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<!-- DFS Xcelerate Taxonomy Labels Linkbase - http://www.dfsco.com/financial-services/ -->
<!-- Version: 6.23.6 -->
<!-- Round: 3 -->
<!-- Creation date: 2018-02-15T13:59:07Z -->
<!-- Copyright (c) 2017 Donnelley Financial, LLC. All Rights Reserved. -->
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xml:lang="en-US" id="id_9887657_1557434_1_1">AOCI Attributable to Parent [Member]</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember_lbl" xml:lang="en-US" id="id_9887657_1550803_1_1">Accumulated Foreign Currency Adjustment Attributable to Parent [Member]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedTranslationAdjustmentMember" xlink:to="us-gaap_AccumulatedTranslationAdjustmentMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US" id="id_9887657_1554127_1_1">Acquired Finite-lived Intangible Assets, Weighted Average Useful Life</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US" id="id_9887657_1554127_2_1">Acquired intangible assets, amortization period, in years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife_lbl" xml:lang="en-US" id="id_9887657_1554127_12_1">Amortization of intangible assets, weighted average period, years</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US" id="id_9887657_1562455_1_1">Additional Paid in Capital, Common Stock</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xml:lang="en-US" id="id_9887657_1562455_2_1">Capital in excess of par value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalCommonStock" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="us-gaap_AdditionalPaidInCapitalMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US" id="id_9887657_1550810_1_1">Additional Paid-in Capital [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xml:lang="en-US" id="id_9887657_1550810_2_1">Capital in Excess of Par Value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdditionalPaidInCapitalMember" xlink:to="us-gaap_AdditionalPaidInCapitalMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xml:lang="en-US" id="id_9887657_1554140_1_1">Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:to="us-gaap_AdjustmentsNoncashItemsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xml:lang="en-US" id="id_9887657_1562452_1_1">Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xml:lang="en-US" id="id_9887657_1562452_2_1">Stock based compensation expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdvertisingCostsPolicyTextBlock" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1547585_1_1">Advertising Costs, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdvertisingCostsPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1547585_2_1">Advertising</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdvertisingCostsPolicyTextBlock" xlink:to="us-gaap_AdvertisingCostsPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AdvertisingExpense" xlink:label="us-gaap_AdvertisingExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AdvertisingExpense_lbl" xml:lang="en-US" id="id_9887657_1565264_1_1">Advertising Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AdvertisingExpense_lbl" xml:lang="en-US" id="id_9887657_1565264_2_1">Advertising costs charged to operations</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdvertisingExpense" xlink:to="us-gaap_AdvertisingExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd#currency_AllCurrenciesDomain" xlink:label="currency_AllCurrenciesDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="currency_AllCurrenciesDomain_lbl" xml:lang="en-US" id="id_9887657_1557464_1_1">All Currencies [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="currency_AllCurrenciesDomain_lbl" xml:lang="en-US" id="id_9887657_1557464_2_1">All Currencies [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="currency_AllCurrenciesDomain" xlink:to="currency_AllCurrenciesDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US" id="id_9887657_1564307_1_1">Allocated Share-based Compensation Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US" id="id_9887657_1564307_2_1">Stock based compensation expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense_lbl" xml:lang="en-US" id="id_9887657_1564307_12_1">Total stock based compensation cost recognized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllocatedShareBasedCompensationExpense" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_AllOtherMember" xlink:label="aos_AllOtherMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_AllOtherMember_lbl" xml:lang="en-US" id="id_9887657_1623684_3_1">All Other [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_AllOtherMember_lbl" xml:lang="en-US" id="id_9887657_1623684_1_1">All Other [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_AllOtherMember_lbl" xml:lang="en-US" id="id_9887657_1623684_2_1">Other</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_AllOtherMember" xlink:to="aos_AllOtherMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1564248_1_1">Allowance for Doubtful Accounts Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1564248_2_1">Allowance for doubtful accounts</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivable" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="dei_AmendmentFlag"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US" id="id_9887657_1550846_1_1">Amendment Flag</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_AmendmentFlag_lbl" xml:lang="en-US" id="id_9887657_1550846_2_1">Amendment Flag</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AmendmentFlag" xlink:to="dei_AmendmentFlag_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_AmortizationOfAdvertisingCosts" xlink:label="aos_AmortizationOfAdvertisingCosts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_AmortizationOfAdvertisingCosts_lbl" xml:lang="en-US" id="id_9887657_1674731_3_1">Amortization associated with prepaid advertising costs.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_AmortizationOfAdvertisingCosts_lbl" xml:lang="en-US" id="id_9887657_1674731_1_1">Amortization Of Advertising Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_AmortizationOfAdvertisingCosts_lbl" xml:lang="en-US" id="id_9887657_1674731_2_1">Amortization of total advertising costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_AmortizationOfAdvertisingCosts" xlink:to="aos_AmortizationOfAdvertisingCosts_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="us-gaap_AmortizationOfIntangibleAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US" id="id_9887657_1567265_1_1">Amortization of Intangible Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmortizationOfIntangibleAssets_lbl" xml:lang="en-US" id="id_9887657_1567265_2_1">Amortization expenses of other intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfIntangibleAssets" xlink:to="us-gaap_AmortizationOfIntangibleAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_AmortizationPeriodOfAdvertisingCosts" xlink:label="aos_AmortizationPeriodOfAdvertisingCosts"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_AmortizationPeriodOfAdvertisingCosts_lbl" xml:lang="en-US" id="id_9887657_1709590_3_1">Amortization of total advertising costs in months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_AmortizationPeriodOfAdvertisingCosts_lbl" xml:lang="en-US" id="id_9887657_1709590_1_1">Amortization Period of Advertising Costs</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_AmortizationPeriodOfAdvertisingCosts_lbl" xml:lang="en-US" id="id_9887657_1709590_2_1">Amortization of total advertising costs, months</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_AmortizationPeriodOfAdvertisingCosts" xlink:to="aos_AmortizationPeriodOfAdvertisingCosts_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax" xlink:label="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1566261_1_1">Defined Benefit Plan, Amount Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Income) Loss, before Tax</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1566261_2_1">Total recognized in net periodic (benefit) cost and other comprehensive loss</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax" xlink:to="us-gaap_AmountRecognizedInNetPeriodicBenefitCostAndOtherComprehensiveIncomeLossBeforeTax_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_AnnuallyMember" xlink:label="aos_AnnuallyMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_AnnuallyMember_lbl" xml:lang="en-US" id="id_9887657_1612844_3_1">Annually [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_AnnuallyMember_lbl" xml:lang="en-US" id="id_9887657_1612844_1_1">Annually [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_AnnuallyMember_lbl" xml:lang="en-US" id="id_9887657_1612844_2_1">Annually</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_AnnuallyMember" xlink:to="aos_AnnuallyMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_AOSmithCombinedCompensationPlanMember" xlink:label="aos_AOSmithCombinedCompensationPlanMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_AOSmithCombinedCompensationPlanMember_lbl" xml:lang="en-US" id="id_9887657_1586498_3_1">A.O.Smith Combined Compensation Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_AOSmithCombinedCompensationPlanMember_lbl" xml:lang="en-US" id="id_9887657_1586498_1_1">A- O- Smith Combined Compensation Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_AOSmithCombinedCompensationPlanMember_lbl" xml:lang="en-US" id="id_9887657_1586498_2_1">A.O. Smith Combined Compensation Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_AOSmithCombinedCompensationPlanMember" xlink:to="aos_AOSmithCombinedCompensationPlanMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_AquasanaMember" xlink:label="aos_AquasanaMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_AquasanaMember_lbl" xml:lang="en-US" id="id_9887657_1570508_3_1">Aquasana [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_AquasanaMember_lbl" xml:lang="en-US" id="id_9887657_1570508_1_1">Aquasana [Member]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardDateAxis_lbl" xml:lang="en-US" id="id_9887657_1547684_1_1">Award Date [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AwardDateAxis_lbl" xml:lang="en-US" id="id_9887657_1547684_2_1">Award Date [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardDateAxis" xlink:to="us-gaap_AwardDateAxis_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardDateDomain_lbl" xml:lang="en-US" id="id_9887657_1547685_1_1">Award Date [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AwardDateDomain_lbl" xml:lang="en-US" id="id_9887657_1547685_2_1">Award Date [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardDateDomain" xlink:to="us-gaap_AwardDateDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="us-gaap_AwardTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_AwardTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1547686_1_1">Award Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_AwardTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1547686_2_1">Award Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="us-gaap_BalanceSheetLocationAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xml:lang="en-US" id="id_9887657_1550919_1_1">Balance Sheet Location [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xml:lang="en-US" id="id_9887657_1550919_2_1">Balance Sheet Location</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationAxis" xlink:to="us-gaap_BalanceSheetLocationAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="us-gaap_BalanceSheetLocationDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xml:lang="en-US" id="id_9887657_1547693_1_1">Balance Sheet Location [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xml:lang="en-US" id="id_9887657_1547693_2_1">Balance Sheet Location [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationDomain" xlink:to="us-gaap_BalanceSheetLocationDomain_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_BankCreditLinesMember_lbl" xml:lang="en-US" id="id_9887657_1698154_3_1">Bank Credit Lines [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_BankCreditLinesMember_lbl" xml:lang="en-US" id="id_9887657_1698154_1_1">Bank Credit Lines [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_BankCreditLinesMember_lbl" xml:lang="en-US" id="id_9887657_1698154_2_1">Bank Credit Lines</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_BankCreditLinesMember" xlink:to="aos_BankCreditLinesMember_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BuildingMember_lbl" xml:lang="en-US" id="id_9887657_1547722_1_1">Building [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BuildingMember_lbl" xml:lang="en-US" id="id_9887657_1547722_2_1">Building</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US" id="id_9887657_1554289_1_1">Business Acquisition, Acquiree [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xml:lang="en-US" id="id_9887657_1554289_2_1">Business Acquisition, Acquiree [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xml:lang="en-US" id="id_9887657_1557586_2_1">Business Acquisition</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xml:lang="en-US" id="id_9887657_1547726_1_1">Business Acquisition [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionLineItems_lbl" xml:lang="en-US" id="id_9887657_1547726_2_1">Business Acquisition [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessAcquisitionLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xml:lang="en-US" id="id_9887657_1550966_1_1">Business Acquisition, Percentage of Voting Interests Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xml:lang="en-US" id="id_9887657_1550966_2_1">Percentage of ownership interest acquired</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:to="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationAcquisitionRelatedCosts_lbl" xml:lang="en-US" id="id_9887657_1565315_2_1">Acquisition-related costs</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationAcquisitionRelatedCosts" xlink:to="us-gaap_BusinessCombinationAcquisitionRelatedCosts_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_BusinessCombinationContingentConsiderationArrangementsConditionsMeasurementPeriod_lbl" xml:lang="en-US" id="id_9887657_1665988_3_1">Business combination, contingent consideration arrangements, conditions measurement period.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_BusinessCombinationContingentConsiderationArrangementsConditionsMeasurementPeriod_lbl" xml:lang="en-US" id="id_9887657_1665988_1_1">Business Combination, Contingent Consideration Arrangements, Conditions Measurement Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_BusinessCombinationContingentConsiderationArrangementsConditionsMeasurementPeriod_lbl" xml:lang="en-US" id="id_9887657_1665988_2_1">Contingent consideration, conditions measurement period</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xml:lang="en-US" id="id_9887657_1563297_1_1">Business Combination, Contingent Consideration, Liability</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_lbl" xml:lang="en-US" id="id_9887657_1563297_2_1">Contingent consideration and holdback</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_BusinessCombinationContingentConsiderationPaid_lbl" xml:lang="en-US" id="id_9887657_1754255_1_1">Business Combination Contingent Consideration Paid</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1554311_2_1">Acquisitions</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual" xlink:label="us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US" id="id_9887657_1564212_1_1">Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US" id="id_9887657_1564212_2_1">Pre tax earnings</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US" id="id_9887657_1561532_1_1">Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_lbl" xml:lang="en-US" id="id_9887657_1561532_2_1">Revenues</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_CommitmentsAndContingenciesTable_lbl" xml:lang="en-US" id="id_9887657_1706419_1_1">Commitments and Contingencies [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_CommitmentsAndContingenciesTable_lbl" xml:lang="en-US" id="id_9887657_1706419_2_1">Commitments and Contingencies [Table]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_ComponentOfNetIncomeTaxAssetsAndLiabilitiesLineItems" xlink:to="aos_ComponentOfNetIncomeTaxAssetsAndLiabilitiesLineItems_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_ComponentOfNetIncomeTaxAssetsAndLiabilitiesTable_lbl" xml:lang="en-US" id="id_9887657_1704868_3_1">Component Of Net Income Tax Assets And Liabilities [Table]</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_ComponentOfNetIncomeTaxAssetsAndLiabilitiesTable" xlink:to="aos_ComponentOfNetIncomeTaxAssetsAndLiabilitiesTable_lbl"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xml:lang="en-US" id="id_9887657_1551119_1_1">Concentration Risk Benchmark [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xml:lang="en-US" id="id_9887657_1551119_2_1">Concentration Risk Benchmark [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xml:lang="en-US" id="id_9887657_1557722_1_1">Concentration Risk Benchmark [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xml:lang="en-US" id="id_9887657_1557722_2_1">Concentration Risk Benchmark [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1557723_1_1">Concentration Risk Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1557723_2_1">Concentration Risk Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskByTypeAxis_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xml:lang="en-US" id="id_9887657_1557730_1_1">Concentration Risk, Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xml:lang="en-US" id="id_9887657_1557730_2_1">Concentration Risk, Percentage</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConcentrationRiskTypeDomain_lbl" xml:lang="en-US" id="id_9887657_1547942_2_1">Concentration Risk Type [Domain]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_CondensedFinancialInformationOfSubsidiariesDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1627094_3_1">Condensed Financial Information of Subsidiaries Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_CondensedFinancialInformationOfSubsidiariesDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1627094_1_1">Condensed Financial Information of Subsidiaries Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_CondensedFinancialInformationOfSubsidiariesDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1627094_2_1">Condensed Financial Information of Subsidiaries Disclosure [Abstract]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConsolidationItemsAxis_lbl" xml:lang="en-US" id="id_9887657_1551140_1_1">Consolidation Items [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConsolidationItemsAxis_lbl" xml:lang="en-US" id="id_9887657_1551140_2_1">Consolidation Items [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConsolidationItemsAxis" xlink:to="us-gaap_ConsolidationItemsAxis_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ConsolidationItemsDomain_lbl" xml:lang="en-US" id="id_9887657_1547920_1_1">Consolidation Items [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConsolidationItemsDomain_lbl" xml:lang="en-US" id="id_9887657_1547920_2_1">Consolidation Items [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConsolidationItemsDomain" xlink:to="us-gaap_ConsolidationItemsDomain_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ConsolidationPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1551148_2_1">Consolidation</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrencyAxis_lbl" xml:lang="en-US" id="id_9887657_1548008_1_1">Currency [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CurrencyAxis_lbl" xml:lang="en-US" id="id_9887657_1548008_2_1">Currency [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrencyAxis" xlink:to="us-gaap_CurrencyAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1565428_1_1">Current Federal Tax Expense (Benefit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1565428_2_1">Current, Federal</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="dei_CurrentFiscalYearEndDate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US" id="id_9887657_1554541_1_1">Current Fiscal Year End Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xml:lang="en-US" id="id_9887657_1554541_2_1">Current Fiscal Year End Date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CurrentFiscalYearEndDate" xlink:to="dei_CurrentFiscalYearEndDate_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1565429_1_1">Current Foreign Tax Expense (Benefit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1565429_2_1">Current, International</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentForeignTaxExpenseBenefit" xlink:to="us-gaap_CurrentForeignTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1567405_1_1">Current State and Local Tax Expense (Benefit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1567405_2_1">Current, State</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CustomerListsMember" xlink:label="us-gaap_CustomerListsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CustomerListsMember_lbl" xml:lang="en-US" id="id_9887657_1548034_1_1">Customer Lists [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CustomerListsMember_lbl" xml:lang="en-US" id="id_9887657_1548034_2_1">Customer Lists</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerListsMember" xlink:to="us-gaap_CustomerListsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_CustomerOneMember" xlink:label="aos_CustomerOneMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_CustomerOneMember_lbl" xml:lang="en-US" id="id_9887657_1569443_3_1">Customer one</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_CustomerOneMember_lbl" xml:lang="en-US" id="id_9887657_1569443_1_1">Customer 1 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_CustomerOneMember_lbl" xml:lang="en-US" id="id_9887657_1569443_2_1">Customer one</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_CustomerOneMember" xlink:to="aos_CustomerOneMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="us-gaap_CustomerRelationshipsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_CustomerRelationshipsMember_lbl" xml:lang="en-US" id="id_9887657_1557816_1_1">Customer Relationships [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_CustomerRelationshipsMember_lbl" xml:lang="en-US" id="id_9887657_1557816_2_1">Customer Relationships</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerRelationshipsMember" xlink:to="us-gaap_CustomerRelationshipsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_CustomerTwoMember" xlink:label="aos_CustomerTwoMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_CustomerTwoMember_lbl" xml:lang="en-US" id="id_9887657_1747550_3_1">Customer two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_CustomerTwoMember_lbl" xml:lang="en-US" id="id_9887657_1747550_1_1">Customer 2 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_CustomerTwoMember_lbl" xml:lang="en-US" id="id_9887657_1747550_2_1">Customer Two</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_CustomerTwoMember" xlink:to="aos_CustomerTwoMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtDisclosureAbstract" xlink:label="us-gaap_DebtDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1554562_1_1">Debt Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1554562_2_1">Debt Disclosure [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureAbstract" xlink:to="us-gaap_DebtDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtDisclosureTextBlock" xlink:label="us-gaap_DebtDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1554563_1_1">Debt Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1554563_2_1">Debt and Lease Commitments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtDisclosureTextBlock" xlink:to="us-gaap_DebtDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="us-gaap_DebtInstrumentAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US" id="id_9887657_1548029_1_1">Debt Instrument [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xml:lang="en-US" id="id_9887657_1548029_2_1">Debt Instrument [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="us-gaap_DebtInstrumentFaceAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US" id="id_9887657_1562344_1_1">Debt Instrument, Face Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xml:lang="en-US" id="id_9887657_1562344_2_1">Debt instrument, issued</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DebtInstrumentFirstInstallmentPaymentYear" xlink:label="aos_DebtInstrumentFirstInstallmentPaymentYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DebtInstrumentFirstInstallmentPaymentYear_lbl" xml:lang="en-US" id="id_9887657_1680779_3_1">Debt Instrument, First Installment Payment, Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DebtInstrumentFirstInstallmentPaymentYear_lbl" xml:lang="en-US" id="id_9887657_1680779_1_1">Debt Instrument, First Installment Payment, Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DebtInstrumentFirstInstallmentPaymentYear_lbl" xml:lang="en-US" id="id_9887657_1680779_2_1">Debt instrument, principle repayment commencement year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DebtInstrumentFirstInstallmentPaymentYear" xlink:to="aos_DebtInstrumentFirstInstallmentPaymentYear_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US" id="id_9887657_1551243_1_1">Debt Instrument, Interest Rate, Stated Percentage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xml:lang="en-US" id="id_9887657_1551243_2_1">Debt instrument, interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="us-gaap_DebtInstrumentLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xml:lang="en-US" id="id_9887657_1557824_1_1">Debt Instrument [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xml:lang="en-US" id="id_9887657_1557824_2_1">Debt Instrument [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DebtInstrumentMaturityDateYear" xlink:label="aos_DebtInstrumentMaturityDateYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DebtInstrumentMaturityDateYear_lbl" xml:lang="en-US" id="id_9887657_1714607_3_1">Debt Instrument Maturity Date Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DebtInstrumentMaturityDateYear_lbl" xml:lang="en-US" id="id_9887657_1714607_1_1">Debt Instrument Maturity Date Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DebtInstrumentMaturityDateYear_lbl" xml:lang="en-US" id="id_9887657_1714607_2_1">Debt instrument maturity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="aos_DebtInstrumentMaturityDateYear_lbl" xml:lang="en-US" id="id_9887657_1714607_12_1">Debt instrument, maturity year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DebtInstrumentMaturityDateYear" xlink:to="aos_DebtInstrumentMaturityDateYear_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="us-gaap_DebtInstrumentNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US" id="id_9887657_1554577_1_1">Debt Instrument, Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xml:lang="en-US" id="id_9887657_1554577_2_1">Debt Instrument, Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentInterest" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentInterest"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentInterest_lbl" xml:lang="en-US" id="id_9887657_1564454_1_1">Debt Instrument, Periodic Payment, Interest</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentInterest_lbl" xml:lang="en-US" id="id_9887657_1564454_2_1">Interest paid</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPaymentInterest" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentInterest_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="us-gaap_DebtInstrumentTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtInstrumentTable_lbl" xml:lang="en-US" id="id_9887657_1557832_1_1">Schedule of Long-term Debt Instruments [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtInstrumentTable_lbl" xml:lang="en-US" id="id_9887657_1557832_2_1">Schedule of Long-term Debt Instruments [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DebtInstrumentTrancheOneMember" xlink:label="aos_DebtInstrumentTrancheOneMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DebtInstrumentTrancheOneMember_lbl" xml:lang="en-US" id="id_9887657_1574384_3_1">Debt Instrument Tranche One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DebtInstrumentTrancheOneMember_lbl" xml:lang="en-US" id="id_9887657_1574384_1_1">Debt Instrument Tranche One [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DebtInstrumentTrancheOneMember_lbl" xml:lang="en-US" id="id_9887657_1574384_2_1">Tranche One</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DebtInstrumentTrancheOneMember" xlink:to="aos_DebtInstrumentTrancheOneMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DebtInstrumentTrancheTwoMember" xlink:label="aos_DebtInstrumentTrancheTwoMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DebtInstrumentTrancheTwoMember_lbl" xml:lang="en-US" id="id_9887657_1724995_3_1">Debt Instrument Tranche Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DebtInstrumentTrancheTwoMember_lbl" xml:lang="en-US" id="id_9887657_1724995_1_1">Debt Instrument Tranche Two [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DebtInstrumentTrancheTwoMember_lbl" xml:lang="en-US" id="id_9887657_1724995_2_1">Tranche Two</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DebtInstrumentTrancheTwoMember" xlink:to="aos_DebtInstrumentTrancheTwoMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DebtSecuritiesMember" xlink:label="us-gaap_DebtSecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DebtSecuritiesMember_lbl" xml:lang="en-US" id="id_9887657_1551260_1_1">Debt Securities [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DebtSecuritiesMember_lbl" xml:lang="en-US" id="id_9887657_1551260_2_1">Debt Securities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtSecuritiesMember" xlink:to="us-gaap_DebtSecuritiesMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible" xlink:label="us-gaap_DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1567421_1_1">Deferred Foreign Income Tax Expense (Benefit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1567421_2_1">Deferred, International</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilities" xlink:label="us-gaap_DeferredIncomeTaxLiabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xml:lang="en-US" id="id_9887657_1561466_1_1">Deferred Tax Liabilities, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredIncomeTaxLiabilities_lbl" xml:lang="en-US" id="id_9887657_1561466_6_1">All other, Liabilities</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1564494_1_1">Deferred State and Local Income Tax Expense (Benefit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xml:lang="en-US" id="id_9887657_1564494_2_1">Deferred, State</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxAssetEnvironmental" xlink:label="aos_DeferredTaxAssetEnvironmental"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxAssetEnvironmental_lbl" xml:lang="en-US" id="id_9887657_1591626_3_1">The tax effect as of the balance sheet date of the amount of the estimated future tax deductions arising from estimated environmental reserves, which can only be deducted for tax purposes when environmental losses are actually incurred, and which can only be realized if sufficient tax-basis income is generated in future periods to enable the deduction to be taken.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxAssetEnvironmental_lbl" xml:lang="en-US" id="id_9887657_1591626_1_1">Deferred Tax Asset Environmental</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DeferredTaxAssetEnvironmental_lbl" xml:lang="en-US" id="id_9887657_1591626_2_1">Environmental, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxAssetEnvironmental" xlink:to="aos_DeferredTaxAssetEnvironmental_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxAssetsAccountsReceivable" xlink:label="aos_DeferredTaxAssetsAccountsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxAssetsAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1579623_3_1">Deferred Tax Assets, Accounts Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxAssetsAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1579623_1_1">Deferred Tax Assets Accounts Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DeferredTaxAssetsAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1579623_2_1">Accounts receivable, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxAssetsAccountsReceivable" xlink:to="aos_DeferredTaxAssetsAccountsReceivable_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets" xlink:label="aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets_lbl" xml:lang="en-US" id="id_9887657_1741416_3_1">Deferred Tax Assets Goodwill And Intangible Assets Intangible Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets_lbl" xml:lang="en-US" id="id_9887657_1741416_1_1">Deferred Tax Assets Goodwill And Intangible Assets Intangible Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets_lbl" xml:lang="en-US" id="id_9887657_1741416_2_1">Intangibles, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets" xlink:to="aos_DeferredTaxAssetsGoodwillAndIntangibleAssetsIntangibleAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsInventory" xlink:label="us-gaap_DeferredTaxAssetsInventory"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsInventory_lbl" xml:lang="en-US" id="id_9887657_1566467_1_1">Deferred Tax Assets, Inventory</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsInventory_lbl" xml:lang="en-US" id="id_9887657_1566467_2_1">Inventories, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsInventory" xlink:to="us-gaap_DeferredTaxAssetsInventory_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xml:lang="en-US" id="id_9887657_1565485_1_1">Deferred Tax Assets, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xml:lang="en-US" id="id_9887657_1565485_2_1">Net asset</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:label="us-gaap_DeferredTaxAssetsNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xml:lang="en-US" id="id_9887657_1567433_1_1">Deferred Tax Assets, Net of Valuation Allowance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xml:lang="en-US" id="id_9887657_1567433_6_1">Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNet" xlink:to="us-gaap_DeferredTaxAssetsNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsOther" xlink:label="us-gaap_DeferredTaxAssetsOther"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xml:lang="en-US" id="id_9887657_1564480_1_1">Deferred Tax Assets, Other</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xml:lang="en-US" id="id_9887657_1564480_2_1">All other, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsOther" xlink:to="us-gaap_DeferredTaxAssetsOther_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment" xlink:label="us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_lbl" xml:lang="en-US" id="id_9887657_1566470_1_1">Deferred Tax Assets, Property, Plant and Equipment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_lbl" xml:lang="en-US" id="id_9887657_1566470_2_1">Property, plant and equipment, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment" xlink:to="us-gaap_DeferredTaxAssetsPropertyPlantAndEquipment_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits_lbl" xml:lang="en-US" id="id_9887657_1567435_1_1">Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Employee Benefits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits_lbl" xml:lang="en-US" id="id_9887657_1567435_2_1">Employee benefits, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves_lbl" xml:lang="en-US" id="id_9887657_1567442_1_1">Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Warranty Reserves</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves_lbl" xml:lang="en-US" id="id_9887657_1567442_2_1">Product liability and warranties, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:to="us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsWarrantyReserves_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxAssetsUndistributedForeignEarnings" xlink:label="aos_DeferredTaxAssetsUndistributedForeignEarnings"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxAssetsUndistributedForeignEarnings_lbl" xml:lang="en-US" id="id_9887657_1605395_3_1">Deferred Tax Assets, Undistributed Foreign Earnings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxAssetsUndistributedForeignEarnings_lbl" xml:lang="en-US" id="id_9887657_1605395_1_1">Deferred Tax Assets, Undistributed Foreign Earnings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DeferredTaxAssetsUndistributedForeignEarnings_lbl" xml:lang="en-US" id="id_9887657_1605395_2_1">Undistributed foreign earnings, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxAssetsUndistributedForeignEarnings" xlink:to="aos_DeferredTaxAssetsUndistributedForeignEarnings_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DeferredTaxAssetsValuationAllowance" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US" id="id_9887657_1564113_1_1">Deferred Tax Assets, Valuation Allowance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US" id="id_9887657_1564113_4_1">Balance at End of Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US" id="id_9887657_1564113_5_1">Balance at Beginning of Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xml:lang="en-US" id="id_9887657_1564113_14_1">Valuation allowance, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsValuationAllowance" xlink:to="us-gaap_DeferredTaxAssetsValuationAllowance_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxAssetTaxLossAndCreditCarryovers" xlink:label="aos_DeferredTaxAssetTaxLossAndCreditCarryovers"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxAssetTaxLossAndCreditCarryovers_lbl" xml:lang="en-US" id="id_9887657_1693658_3_1">The sum of the tax effects as of the balance sheet date of the amount of excesses of tax deductions over gross income in a year which cannot be used on the tax returns in the current year but can be carried forward to reduce taxable income or income taxes payable in a future year, for which there must be sufficient tax-basis income to utilize a portion or all of the carryforward amount to realize the deferred tax asset and the tax effect as of the balance sheet date of the amount of future tax deductions arising from all unused tax credit carryforwards which have been reduced by a valuation allowance.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxAssetTaxLossAndCreditCarryovers_lbl" xml:lang="en-US" id="id_9887657_1693658_1_1">Deferred Tax Asset Tax Loss And Credit Carryovers</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DeferredTaxAssetTaxLossAndCreditCarryovers_lbl" xml:lang="en-US" id="id_9887657_1693658_2_1">Tax loss and credit carryovers, Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxAssetTaxLossAndCreditCarryovers" xlink:to="aos_DeferredTaxAssetTaxLossAndCreditCarryovers_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxLiabilitiesAccountsReceivable" xlink:label="aos_DeferredTaxLiabilitiesAccountsReceivable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxLiabilitiesAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1704715_3_1">Deferred Tax Liabilities Accounts Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxLiabilitiesAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1704715_1_1">Deferred Tax Liabilities Accounts Receivable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DeferredTaxLiabilitiesAccountsReceivable_lbl" xml:lang="en-US" id="id_9887657_1704715_2_1">Accounts receivable, Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxLiabilitiesAccountsReceivable" xlink:to="aos_DeferredTaxLiabilitiesAccountsReceivable_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxLiabilitiesEnvironmentalTrustFunds" xlink:label="aos_DeferredTaxLiabilitiesEnvironmentalTrustFunds"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxLiabilitiesEnvironmentalTrustFunds_lbl" xml:lang="en-US" id="id_9887657_1583119_3_1">Deferred Tax Liabilities, Environmental Trust Funds</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxLiabilitiesEnvironmentalTrustFunds_lbl" xml:lang="en-US" id="id_9887657_1583119_1_1">Deferred Tax Liabilities, Environmental Trust Funds</label>
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    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxLiabilitiesTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:label="aos_DeferredTaxLiabilitiesTaxDeferredExpenseReservesAndAccrualsWarrantyReserves"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxLiabilitiesTaxDeferredExpenseReservesAndAccrualsWarrantyReserves_lbl" xml:lang="en-US" id="id_9887657_1688542_3_1">Deferred Tax Liabilities Tax Deferred Expense Reserves and Accruals Warranty Reserves</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxLiabilitiesTaxDeferredExpenseReservesAndAccrualsWarrantyReserves_lbl" xml:lang="en-US" id="id_9887657_1688542_1_1">Deferred Tax Liabilities Tax Deferred Expense Reserves and Accruals Warranty Reserves</label>
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    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DeferredTaxLiabilitiesTaxDeferredExpenseReservesAndAccrualsWarrantyReserves" xlink:to="aos_DeferredTaxLiabilitiesTaxDeferredExpenseReservesAndAccrualsWarrantyReserves_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_lbl" xml:lang="en-US" id="id_9887657_1562312_1_1">Deferred Tax Liabilities, Undistributed Foreign Earnings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_lbl" xml:lang="en-US" id="id_9887657_1562312_2_1">Undistributed foreign earnings, Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings" xlink:to="us-gaap_DeferredTaxLiabilitiesUndistributedForeignEarnings_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxLiabilitiesValuationAllowance" xlink:label="aos_DeferredTaxLiabilitiesValuationAllowance"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxLiabilitiesValuationAllowance_lbl" xml:lang="en-US" id="id_9887657_1612986_3_1">Deferred Tax Liabilities, Valuation Allowance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DeferredTaxLiabilitiesValuationAllowance_lbl" xml:lang="en-US" id="id_9887657_1612986_1_1">Deferred Tax Liabilities, Valuation Allowance</label>
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    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DeferredTaxLiabilityTaxLossAndCreditCarryovers" xlink:label="aos_DeferredTaxLiabilityTaxLossAndCreditCarryovers"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DeferredTaxLiabilityTaxLossAndCreditCarryovers_lbl" xml:lang="en-US" id="id_9887657_1698124_3_1">Deferred Tax Liability Tax Loss And Credit Carryovers</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPensionPlanLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1561450_2_1">Pension liabilities</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPensionPlansAndDefinedBenefitPostretirementPlansDisclosureAbstract" xlink:label="us-gaap_DefinedBenefitPensionPlansAndDefinedBenefitPostretirementPlansDisclosureAbstract"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_lbl" xml:lang="en-US" id="id_9887657_1562303_1_1">Defined Benefit Plan, Accumulated Benefit Obligation</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_lbl" xml:lang="en-US" id="id_9887657_1562303_2_1">Accumulated benefit obligation (ABO) at December 31</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1564500_1_1">Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1564500_6_1">Total recognized in accumulated other comprehensive loss</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1563191_1_1">Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1563191_14_1">Net actuarial loss (gain)</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_lbl" xml:lang="en-US" id="id_9887657_1566460_2_1">Prior service cost</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1565498_2_1">Actual return on plan assets</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanDisclosureLineItems_lbl" xml:lang="en-US" id="id_9887657_1554634_2_1">Defined Benefit Plan Disclosure [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:to="us-gaap_DefinedBenefitPlanDisclosureLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_lbl" xml:lang="en-US" id="id_9887657_1561439_1_1">Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_lbl" xml:lang="en-US" id="id_9887657_1561439_2_1">Estimated net actuarial gain that will be amortized from accumulated other comprehensive loss into net periodic benefit cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear" xlink:to="us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_lbl" xml:lang="en-US" id="id_9887657_1567456_1_1">Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_lbl" xml:lang="en-US" id="id_9887657_1567456_2_1">Estimated net prior service cost that will be amortized from accumulated other comprehensive loss into net periodic benefit cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear" xlink:to="us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearSixThroughTen" xlink:label="aos_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearSixThroughTen"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearSixThroughTen_lbl" xml:lang="en-US" id="id_9887657_1676799_3_1">Defined Benefit Plan, Expected Future Benefit Payments in Year Six Through Ten</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearSixThroughTen_lbl" xml:lang="en-US" id="id_9887657_1676799_1_1">Defined Benefit Plan, Expected Future Benefit Payments in Year Six Through Ten</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DefinedBenefitPlanExpectedFutureBenefitPaymentsInYearSixThroughTen_lbl" xml:lang="en-US" id="id_9887657_1676799_2_1">2023 - 2027</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xml:lang="en-US" id="id_9887657_1563184_1_1">Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl" xml:lang="en-US" id="id_9887657_1563184_2_1">2018</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xml:lang="en-US" id="id_9887657_1563187_1_1">Defined Benefit Plan, Expected Future Benefit Payment, Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl" xml:lang="en-US" id="id_9887657_1563187_2_1">2022</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xml:lang="en-US" id="id_9887657_1564106_1_1">Defined Benefit Plan, Expected Future Benefit Payment, Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl" xml:lang="en-US" id="id_9887657_1564106_2_1">2021</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour" xlink:to="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xml:lang="en-US" id="id_9887657_1561438_1_1">Defined Benefit Plan, Expected Future Benefit Payment, Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_lbl" xml:lang="en-US" id="id_9887657_1561438_2_1">2020</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xml:lang="en-US" id="id_9887657_1564107_1_1">Defined Benefit Plan, Expected Future Benefit Payment, Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_lbl" xml:lang="en-US" id="id_9887657_1564107_2_1">2019</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1563178_1_1">Defined Benefit Plan, Expected Return (Loss) on Plan Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1563178_14_1">Expected return on plan assets</label>
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    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets" xlink:label="aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1595463_3_1">Defined benefit plan fair value of non-investment plan assets.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1595463_1_1">Defined Benefit Plan Fair Value Of Non Investment Plan Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1595463_2_1">Non-investment plan assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets" xlink:to="aos_DefinedBenefitPlanFairValueOfNonInvestmentPlanAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1567459_1_1">Defined Benefit Plan, Fair Value of Plan Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1567459_4_1">Plan assets at end of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1567459_5_1">Plan assets at beginning of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1567459_2_1">Total fair value of plan asset investments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets" xlink:to="us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_DefinedBenefitPlanFairValueOfPlanAssetsIncludingNoninvestmentPlanAssets" xlink:label="aos_DefinedBenefitPlanFairValueOfPlanAssetsIncludingNoninvestmentPlanAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_DefinedBenefitPlanFairValueOfPlanAssetsIncludingNoninvestmentPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1600564_3_1">Defined Benefit Plan Fair Value of Plan Assets Including Non-Investment Plan Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_DefinedBenefitPlanFairValueOfPlanAssetsIncludingNoninvestmentPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1600564_1_1">Defined Benefit Plan Fair Value of Plan Assets Including Non-Investment Plan Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="aos_DefinedBenefitPlanFairValueOfPlanAssetsIncludingNoninvestmentPlanAssets_lbl" xml:lang="en-US" id="id_9887657_1600564_6_1">Total plan assets</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" xml:lang="en-US" id="id_9887657_1566486_1_1">Defined Benefit Plan, Funded (Unfunded) Status of Plan</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl" xml:lang="en-US" id="id_9887657_1566486_6_1">Funded status</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanFundedStatusOfPlan" xlink:to="us-gaap_DefinedBenefitPlanFundedStatusOfPlan_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear" xlink:label="us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_lbl" xml:lang="en-US" id="id_9887657_1554640_1_1">Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanHealthCareCostTrendRateAssumedNextFiscalYear_lbl" xml:lang="en-US" id="id_9887657_1554640_2_1">Health care cost trend rate assumed for next year</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="us-gaap_DefinedBenefitPlanInterestCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xml:lang="en-US" id="id_9887657_1564511_1_1">Defined Benefit Plan, Interest Cost</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xml:lang="en-US" id="id_9887657_1564511_2_1">Interest cost</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanInterestCost_lbl" xml:lang="en-US" id="id_9887657_1564511_14_1">Interest cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanInterestCost" xlink:to="us-gaap_DefinedBenefitPlanInterestCost_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xml:lang="en-US" id="id_9887657_1566487_1_1">Defined Benefit Plan, Net Periodic Benefit Cost (Credit)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl" xml:lang="en-US" id="id_9887657_1566487_6_1">Defined-benefit plan (income) cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:to="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditIncreaseDecreaseForPlanAmendment" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditIncreaseDecreaseForPlanAmendment"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditIncreaseDecreaseForPlanAmendment_lbl" xml:lang="en-US" id="id_9887657_1566488_1_1">Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Increase (Decrease) for Plan Amendment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditIncreaseDecreaseForPlanAmendment_lbl" xml:lang="en-US" id="id_9887657_1566488_2_1">Decrease in the service and interest components for pension cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditIncreaseDecreaseForPlanAmendment" xlink:to="us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditIncreaseDecreaseForPlanAmendment_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAmendments" xlink:label="us-gaap_DefinedBenefitPlanPlanAmendments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_DefinedBenefitPlanPlanAmendments_lbl" xml:lang="en-US" id="id_9887657_1563177_1_1">Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_DefinedBenefitPlanPlanAmendments_lbl" xml:lang="en-US" id="id_9887657_1563177_14_1">Plan amendments</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xml:lang="en-US" id="id_9887657_1548400_2_1">Fair Value Measurements, Recurring and Nonrecurring [Table]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xml:lang="en-US" id="id_9887657_1551627_1_1">Fair Value, Inputs, Level 1 [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xml:lang="en-US" id="id_9887657_1551627_2_1">Quoted Prices In Active Markets For Identical Assets (Level 1)</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_lbl" xml:lang="en-US" id="id_9887657_1551671_2_1">Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US" id="id_9887657_1563062_1_1">Finite-Lived Intangible Assets, Accumulated Amortization</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl" xml:lang="en-US" id="id_9887657_1563062_14_1">Accumulated Amortization, Amortizable intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xml:lang="en-US" id="id_9887657_1555137_1_1">Finite-Lived Intangible Assets by Major Class [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xml:lang="en-US" id="id_9887657_1555137_2_1">Finite-Lived Intangible Assets by Major Class</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US" id="id_9887657_1567620_1_1">Finite-Lived Intangible Assets, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross_lbl" xml:lang="en-US" id="id_9887657_1567620_2_1">Gross Carrying Amount, Amortizable intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsGross" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xml:lang="en-US" id="id_9887657_1555138_1_1">Finite-Lived Intangible Assets [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl" xml:lang="en-US" id="id_9887657_1555138_2_1">Finite-Lived Intangible Assets [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_lbl" xml:lang="en-US" id="id_9887657_1551756_1_1">Finite-Lived Intangible Assets, Major Class Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_lbl" xml:lang="en-US" id="id_9887657_1551756_2_1">Finite-Lived Intangible Assets, Major Class Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xml:lang="en-US" id="id_9887657_1567616_1_1">Finite-Lived Intangible Assets, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_lbl" xml:lang="en-US" id="id_9887657_1567616_6_1">Net, Amortizable intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetsNet" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xml:lang="en-US" id="id_9887657_1548566_1_1">Finite-Lived Intangible Asset, Useful Life</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl" xml:lang="en-US" id="id_9887657_1548566_2_1">Intangible assets estimated useful lives</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_FixedIncomeSecuritiesMember" xlink:label="us-gaap_FixedIncomeSecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_FixedIncomeSecuritiesMember_lbl" xml:lang="en-US" id="id_9887657_1555131_1_1">Fixed Income Securities [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_FixedIncomeSecuritiesMember_lbl" xml:lang="en-US" id="id_9887657_1555131_2_1">Fixed Income Securities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FixedIncomeSecuritiesMember" xlink:to="us-gaap_FixedIncomeSecuritiesMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCountryMember" xlink:label="us-gaap_ForeignCountryMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCountryMember_lbl" xml:lang="en-US" id="id_9887657_1551768_1_1">Foreign Tax Authority [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignCountryMember_lbl" xml:lang="en-US" id="id_9887657_1551768_2_1">Non-U.S.</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1551765_1_1">Foreign Currency Transactions and Translations Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1551765_2_1">Foreign currency translation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock" xlink:to="us-gaap_ForeignCurrencyTransactionsAndTranslationsPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="us-gaap_ForeignExchangeContractMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignExchangeContractMember_lbl" xml:lang="en-US" id="id_9887657_1558418_1_1">Foreign Exchange Contract [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignExchangeContractMember_lbl" xml:lang="en-US" id="id_9887657_1558418_2_1">Foreign Currency Contracts</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeContractMember" xlink:to="us-gaap_ForeignExchangeContractMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:label="us-gaap_ForeignExchangeForwardMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xml:lang="en-US" id="id_9887657_1551767_1_1">Foreign Exchange Forward [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xml:lang="en-US" id="id_9887657_1551767_2_1">Foreign currency forward contracts</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeForwardMember" xlink:to="us-gaap_ForeignExchangeForwardMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ForeignPlanMember" xlink:label="us-gaap_ForeignPlanMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ForeignPlanMember_lbl" xml:lang="en-US" id="id_9887657_1555147_1_1">Foreign Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ForeignPlanMember_lbl" xml:lang="en-US" id="id_9887657_1555147_2_1">Foreign Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignPlanMember" xlink:to="us-gaap_ForeignPlanMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_FourPointSevenFiveToElevenPointFiveZeroMember" xlink:label="aos_FourPointSevenFiveToElevenPointFiveZeroMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_FourPointSevenFiveToElevenPointFiveZeroMember_lbl" xml:lang="en-US" id="id_9887657_1695062_3_1">Four Point Seven Five to Eleven Point Five Zero [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_FourPointSevenFiveToElevenPointFiveZeroMember_lbl" xml:lang="en-US" id="id_9887657_1695062_1_1">Four Point Seven Five to Eleven Point Five Zero [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_FourPointSevenFiveToElevenPointFiveZeroMember_lbl" xml:lang="en-US" id="id_9887657_1695062_2_1">$4.75 to $11.50</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd#currency_GBP" xlink:label="currency_GBP"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="currency_GBP_lbl" xml:lang="en-US" id="id_9887657_1555186_1_1">United Kingdom, Pounds</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="currency_GBP_lbl" xml:lang="en-US" id="id_9887657_1555186_2_1">British pound</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="currency_GBP" xlink:to="currency_GBP_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GeographicConcentrationRiskMember" xlink:label="us-gaap_GeographicConcentrationRiskMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GeographicConcentrationRiskMember_lbl" xml:lang="en-US" id="id_9887657_1555195_1_1">Geographic Concentration Risk [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GeographicConcentrationRiskMember_lbl" xml:lang="en-US" id="id_9887657_1555195_2_1">Geographic Concentration Risk</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeographicConcentrationRiskMember" xlink:to="us-gaap_GeographicConcentrationRiskMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Goodwill" xlink:label="us-gaap_Goodwill"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US" id="id_9887657_1567638_1_1">Goodwill</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US" id="id_9887657_1567638_4_1">Ending balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US" id="id_9887657_1567638_5_1">Beginning balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_Goodwill_lbl" xml:lang="en-US" id="id_9887657_1567638_2_1">Goodwill</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Goodwill" xlink:to="us-gaap_Goodwill_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xml:lang="en-US" id="id_9887657_1567639_1_1">Goodwill, Acquired During Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_GoodwillAcquiredDuringPeriod_lbl" xml:lang="en-US" id="id_9887657_1567639_2_1">Acquisitions</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xml:lang="en-US" id="id_9887657_1558622_1_1">Indefinite-lived Intangible Assets [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl" xml:lang="en-US" id="id_9887657_1558622_2_1">Indefinite-lived Intangible Assets [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1567724_1_1">Indefinite-Lived Intangible Assets (Excluding Goodwill)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1567724_2_1">Gross Carrying Amount, indefinite-lived intangible assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1567724_12_1">Net, Indefinite-lived intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl" xml:lang="en-US" id="id_9887657_1558634_1_1">Indefinite-lived Intangible Assets, Major Class Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl" xml:lang="en-US" id="id_9887657_1558634_2_1">Indefinite-lived Intangible Assets, Major Class Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1567740_1_1">Intangible Assets, Gross (Excluding Goodwill)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IntangibleAssetsGrossExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1567740_2_1">Gross Carrying Amount, Total intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsGrossExcludingGoodwill_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1565770_1_1">Intangible Assets, Net (Excluding Goodwill)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1565770_2_1">Other intangibles</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl" xml:lang="en-US" id="id_9887657_1565770_6_1">Net, Total intangible assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestCostsCapitalized" xlink:label="us-gaap_InterestCostsCapitalized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestCostsCapitalized_lbl" xml:lang="en-US" id="id_9887657_1567761_1_1">Interest Costs Capitalized</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestCostsCapitalized_lbl" xml:lang="en-US" id="id_9887657_1567761_2_1">Capitalized interest expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestCostsCapitalized" xlink:to="us-gaap_InterestCostsCapitalized_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InterestExpense" xlink:label="us-gaap_InterestExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US" id="id_9887657_1564735_1_1">Interest Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US" id="id_9887657_1564735_2_1">Interest expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_InterestExpense_lbl" xml:lang="en-US" id="id_9887657_1564735_14_1">Interest expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpense" xlink:to="us-gaap_InterestExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InternalRevenueServiceIRSMember" xlink:label="us-gaap_InternalRevenueServiceIRSMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InternalRevenueServiceIRSMember_lbl" xml:lang="en-US" id="id_9887657_1548794_1_1">Internal Revenue Service (IRS) [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InternalRevenueServiceIRSMember_lbl" xml:lang="en-US" id="id_9887657_1548794_2_1">U.S. federal</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InternalRevenueServiceIRSMember" xlink:to="us-gaap_InternalRevenueServiceIRSMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_IntersegmentEliminationMember" xlink:label="us-gaap_IntersegmentEliminationMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_IntersegmentEliminationMember_lbl" xml:lang="en-US" id="id_9887657_1548795_1_1">Intersegment Eliminations [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_IntersegmentEliminationMember_lbl" xml:lang="en-US" id="id_9887657_1548795_2_1">Inter-segment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IntersegmentEliminationMember" xlink:to="us-gaap_IntersegmentEliminationMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_InventoriesLineItems" xlink:label="aos_InventoriesLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_InventoriesLineItems_lbl" xml:lang="en-US" id="id_9887657_1629330_3_1">Inventories [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_InventoriesLineItems_lbl" xml:lang="en-US" id="id_9887657_1629330_1_1">Inventories [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_InventoriesLineItems_lbl" xml:lang="en-US" id="id_9887657_1629330_2_1">Inventories [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_InventoriesLineItems" xlink:to="aos_InventoriesLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_InventoriesTable" xlink:label="aos_InventoriesTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_InventoriesTable_lbl" xml:lang="en-US" id="id_9887657_1650100_3_1">Inventories [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_InventoriesTable_lbl" xml:lang="en-US" id="id_9887657_1650100_1_1">Inventories [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_InventoriesTable_lbl" xml:lang="en-US" id="id_9887657_1650100_2_1">Inventories [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_InventoriesTable" xlink:to="aos_InventoriesTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryCurrentTable" xlink:label="us-gaap_InventoryCurrentTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryCurrentTable_lbl" xml:lang="en-US" id="id_9887657_1555394_1_1">Inventory, Current [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryCurrentTable_lbl" xml:lang="en-US" id="id_9887657_1555394_2_1">Inventory, Current [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryCurrentTable" xlink:to="us-gaap_InventoryCurrentTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryDisclosureAbstract" xlink:label="us-gaap_InventoryDisclosureAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1555395_1_1">Inventory Disclosure [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryDisclosureAbstract_lbl" xml:lang="en-US" id="id_9887657_1555395_2_1">Inventory Disclosure [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureAbstract" xlink:to="us-gaap_InventoryDisclosureAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryDisclosureTextBlock" xlink:label="us-gaap_InventoryDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1548804_1_1">Inventory Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1548804_2_1">Inventories</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryDisclosureTextBlock" xlink:to="us-gaap_InventoryDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryFinishedGoods" xlink:label="us-gaap_InventoryFinishedGoods"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryFinishedGoods_lbl" xml:lang="en-US" id="id_9887657_1565793_1_1">Inventory, Finished Goods, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryFinishedGoods_lbl" xml:lang="en-US" id="id_9887657_1565793_2_1">Finished products</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryFinishedGoods" xlink:to="us-gaap_InventoryFinishedGoods_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryGross" xlink:label="us-gaap_InventoryGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryGross_lbl" xml:lang="en-US" id="id_9887657_1564767_1_1">Inventory, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InventoryGross_lbl" xml:lang="en-US" id="id_9887657_1564767_6_1">Inventories, at FIFO cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryGross" xlink:to="us-gaap_InventoryGross_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryGrossAbstract" xlink:label="us-gaap_InventoryGrossAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryGrossAbstract_lbl" xml:lang="en-US" id="id_9887657_1558679_1_1">Inventory, Gross [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryGrossAbstract_lbl" xml:lang="en-US" id="id_9887657_1558679_2_1">Inventories</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryGrossAbstract" xlink:to="us-gaap_InventoryGrossAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryLIFOReserve" xlink:label="us-gaap_InventoryLIFOReserve"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryLIFOReserve_lbl" xml:lang="en-US" id="id_9887657_1563846_1_1">Inventory, LIFO Reserve</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_InventoryLIFOReserve_lbl" xml:lang="en-US" id="id_9887657_1563846_14_1">LIFO reserve</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryLIFOReserve" xlink:to="us-gaap_InventoryLIFOReserve_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryLineItems" xlink:label="us-gaap_InventoryLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryLineItems_lbl" xml:lang="en-US" id="id_9887657_1548807_1_1">Inventory [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryLineItems_lbl" xml:lang="en-US" id="id_9887657_1548807_2_1">Inventory [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryLineItems" xlink:to="us-gaap_InventoryLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryNet" xlink:label="us-gaap_InventoryNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US" id="id_9887657_1565797_1_1">Inventory, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US" id="id_9887657_1565797_2_1">Inventories</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_InventoryNet_lbl" xml:lang="en-US" id="id_9887657_1565797_6_1">Net inventory</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryNet" xlink:to="us-gaap_InventoryNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryPolicyTextBlock" xlink:label="us-gaap_InventoryPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1548813_1_1">Inventory, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1548813_2_1">Inventory valuation</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryPolicyTextBlock" xlink:to="us-gaap_InventoryPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryRawMaterials" xlink:label="us-gaap_InventoryRawMaterials"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryRawMaterials_lbl" xml:lang="en-US" id="id_9887657_1564771_1_1">Inventory, Raw Materials, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryRawMaterials_lbl" xml:lang="en-US" id="id_9887657_1564771_2_1">Raw materials</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryRawMaterials" xlink:to="us-gaap_InventoryRawMaterials_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InventoryWorkInProcess" xlink:label="us-gaap_InventoryWorkInProcess"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InventoryWorkInProcess_lbl" xml:lang="en-US" id="id_9887657_1567767_1_1">Inventory, Work in Process, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InventoryWorkInProcess_lbl" xml:lang="en-US" id="id_9887657_1567767_2_1">Work in process</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryWorkInProcess" xlink:to="us-gaap_InventoryWorkInProcess_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentTypeAxis" xlink:label="us-gaap_InvestmentTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1555454_1_1">Investment Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InvestmentTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1555454_2_1">Investment Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentTypeAxis" xlink:to="us-gaap_InvestmentTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_InvestmentTypeCategorizationMember" xlink:label="us-gaap_InvestmentTypeCategorizationMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xml:lang="en-US" id="id_9887657_1552094_1_1">Investments [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xml:lang="en-US" id="id_9887657_1552094_2_1">Investments [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentTypeCategorizationMember" xlink:to="us-gaap_InvestmentTypeCategorizationMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LandMember" xlink:label="us-gaap_LandMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LandMember_lbl" xml:lang="en-US" id="id_9887657_1558783_1_1">Land [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LandMember_lbl" xml:lang="en-US" id="id_9887657_1558783_2_1">Land</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LandMember" xlink:to="us-gaap_LandMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LatestTaxYearMember" xlink:label="us-gaap_LatestTaxYearMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LatestTaxYearMember_lbl" xml:lang="en-US" id="id_9887657_1552119_1_1">Latest Tax Year [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LatestTaxYearMember_lbl" xml:lang="en-US" id="id_9887657_1552119_2_1">Latest Tax Year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LatestTaxYearMember" xlink:to="us-gaap_LatestTaxYearMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_LeasesFutureMinimumPaymentsLineItems" xlink:label="aos_LeasesFutureMinimumPaymentsLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_LeasesFutureMinimumPaymentsLineItems_lbl" xml:lang="en-US" id="id_9887657_1584546_3_1">Leases Future Minimum Payments [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_LeasesFutureMinimumPaymentsLineItems_lbl" xml:lang="en-US" id="id_9887657_1584546_1_1">Leases Future Minimum Payments [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_LeasesFutureMinimumPaymentsLineItems_lbl" xml:lang="en-US" id="id_9887657_1584546_2_1">Leases Future Minimum Payments [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_LeasesFutureMinimumPaymentsLineItems" xlink:to="aos_LeasesFutureMinimumPaymentsLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_LeasesFutureMinimumPaymentsTable" xlink:label="aos_LeasesFutureMinimumPaymentsTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_LeasesFutureMinimumPaymentsTable_lbl" xml:lang="en-US" id="id_9887657_1614457_3_1">Leases Future Minimum Payments [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_LeasesFutureMinimumPaymentsTable_lbl" xml:lang="en-US" id="id_9887657_1614457_1_1">Leases Future Minimum Payments [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_LeasesFutureMinimumPaymentsTable_lbl" xml:lang="en-US" id="id_9887657_1614457_2_1">Leases Future Minimum Payments [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_LeasesFutureMinimumPaymentsTable" xlink:to="aos_LeasesFutureMinimumPaymentsTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="dei_LegalEntityAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US" id="id_9887657_1552126_1_1">Legal Entity [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_LegalEntityAxis_lbl" xml:lang="en-US" id="id_9887657_1552126_2_1">Legal Entity [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_Liabilities" xlink:label="us-gaap_Liabilities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US" id="id_9887657_1561154_1_1">Liabilities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_Liabilities_lbl" xml:lang="en-US" id="id_9887657_1561154_6_1">Total Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAbstract" xlink:label="us-gaap_LiabilitiesAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAbstract_lbl" xml:lang="en-US" id="id_9887657_1552179_1_1">Liabilities [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LiabilitiesAbstract_lbl" xml:lang="en-US" id="id_9887657_1552179_2_1">Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAbstract" xlink:to="us-gaap_LiabilitiesAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US" id="id_9887657_1561155_1_1">Liabilities and Equity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xml:lang="en-US" id="id_9887657_1561155_6_1">Total Liabilities and Stockholders' Equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="us-gaap_LiabilitiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US" id="id_9887657_1563831_1_1">Liabilities, Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xml:lang="en-US" id="id_9887657_1563831_6_1">Total Current Liabilities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl" xml:lang="en-US" id="id_9887657_1561126_1_1">Line of Credit Facility, Current Borrowing Capacity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl" xml:lang="en-US" id="id_9887657_1561126_2_1">Multi-currency revolving credit agreement</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityExpirationDate1" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1_lbl" xml:lang="en-US" id="id_9887657_1555599_1_1">Line of Credit Facility, Expiration Date</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1_lbl" xml:lang="en-US" id="id_9887657_1555599_2_1">Revolving credit facility, expiration date</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityExpirationDate1" xlink:to="us-gaap_LineOfCreditFacilityExpirationDate1_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl" xml:lang="en-US" id="id_9887657_1555601_1_1">Line of Credit Facility, Interest Rate at Period End</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl" xml:lang="en-US" id="id_9887657_1555601_2_1">Line of credit facility, average year-end interest rate</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd" xlink:to="us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US" id="id_9887657_1561998_1_1">Line of Credit Facility, Maximum Borrowing Capacity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xml:lang="en-US" id="id_9887657_1561998_2_1">Multi-currency revolving credit agreement, maximum amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongMember" xlink:label="us-gaap_LongMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongMember_lbl" xml:lang="en-US" id="id_9887657_1558943_1_1">Long [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongMember_lbl" xml:lang="en-US" id="id_9887657_1558943_2_1">Buy</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongMember" xlink:to="us-gaap_LongMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebt" xlink:label="us-gaap_LongTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US" id="id_9887657_1563803_1_1">Long-term Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebt_lbl" xml:lang="en-US" id="id_9887657_1563803_2_1">Debt</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtByMaturityAbstract" xlink:label="us-gaap_LongTermDebtByMaturityAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtByMaturityAbstract_lbl" xml:lang="en-US" id="id_9887657_1555646_1_1">Long-term Debt, Fiscal Year Maturity [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtByMaturityAbstract_lbl" xml:lang="en-US" id="id_9887657_1555646_2_1">Debt And Lease Commitments [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtByMaturityAbstract" xlink:to="us-gaap_LongTermDebtByMaturityAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:label="us-gaap_LongTermDebtCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtCurrent_lbl" xml:lang="en-US" id="id_9887657_1563791_1_1">Long-term Debt, Current Maturities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtCurrent_lbl" xml:lang="en-US" id="id_9887657_1563791_2_1">Less long-term debt due within one year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_LongTermDebtCurrent_lbl" xml:lang="en-US" id="id_9887657_1563791_12_1">Long-term debt due within one year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtCurrent" xlink:to="us-gaap_LongTermDebtCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xml:lang="en-US" id="id_9887657_1561106_1_1">Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xml:lang="en-US" id="id_9887657_1561106_2_1">2018</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xml:lang="en-US" id="id_9887657_1561108_1_1">Long-term Debt, Maturities, Repayments of Principal in Year Five</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xml:lang="en-US" id="id_9887657_1561108_2_1">2022</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xml:lang="en-US" id="id_9887657_1563799_1_1">Long-term Debt, Maturities, Repayments of Principal in Year Four</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xml:lang="en-US" id="id_9887657_1563799_2_1">2021</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xml:lang="en-US" id="id_9887657_1563800_1_1">Long-term Debt, Maturities, Repayments of Principal in Year Three</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xml:lang="en-US" id="id_9887657_1563800_2_1">2020</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xml:lang="en-US" id="id_9887657_1562836_1_1">Long-term Debt, Maturities, Repayments of Principal in Year Two</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xml:lang="en-US" id="id_9887657_1562836_2_1">2019</label>
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    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems_lbl" xml:lang="en-US" id="id_9887657_1581886_3_1">Long Term Debt Maturities Repayments Of Principal [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems_lbl" xml:lang="en-US" id="id_9887657_1581886_1_1">Long Term Debt Maturities Repayments Of Principal [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems_lbl" xml:lang="en-US" id="id_9887657_1581886_2_1">Long Term Debt Maturities Repayments Of Principal [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems" xlink:to="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable_lbl" xml:lang="en-US" id="id_9887657_1631321_3_1">Long Term Debt Maturities Repayments Of Principal [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable_lbl" xml:lang="en-US" id="id_9887657_1631321_1_1">Long Term Debt Maturities Repayments Of Principal [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable_lbl" xml:lang="en-US" id="id_9887657_1631321_2_1">Long Term Debt Maturities Repayments Of Principal [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable" xlink:to="aos_LongTermDebtMaturitiesRepaymentsOfPrincipalTable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:label="us-gaap_LongTermDebtNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1561976_1_1">Long-term Debt, Excluding Current Maturities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1561976_2_1">Long-term debt</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="us-gaap_LongtermDebtTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1552305_1_1">Long-term Debt, Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongtermDebtTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1552305_2_1">Long-term Debt, Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeAxis" xlink:to="us-gaap_LongtermDebtTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="us-gaap_LongtermDebtTypeDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xml:lang="en-US" id="id_9887657_1555658_1_1">Long-term Debt, Type [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_LongtermDebtTypeDomain_lbl" xml:lang="en-US" id="id_9887657_1555658_2_1">Long-term Debt, Type [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongtermDebtTypeDomain" xlink:to="us-gaap_LongtermDebtTypeDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MajorCustomersAxis" xlink:label="us-gaap_MajorCustomersAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MajorCustomersAxis_lbl" xml:lang="en-US" id="id_9887657_1558989_1_1">Customer [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MajorCustomersAxis_lbl" xml:lang="en-US" id="id_9887657_1558989_2_1">Customer [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MajorCustomersAxis" xlink:to="us-gaap_MajorCustomersAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:label="us-gaap_MarketableSecuritiesCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesCurrent_lbl" xml:lang="en-US" id="id_9887657_1566866_1_1">Marketable Securities, Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MarketableSecuritiesCurrent_lbl" xml:lang="en-US" id="id_9887657_1566866_2_1">Marketable securities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesCurrent" xlink:to="us-gaap_MarketableSecuritiesCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_MarketableSecuritiesMaturityPeriod" xlink:label="aos_MarketableSecuritiesMaturityPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_MarketableSecuritiesMaturityPeriod_lbl" xml:lang="en-US" id="id_9887657_1710687_3_1">Marketable Securities Maturity Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_MarketableSecuritiesMaturityPeriod_lbl" xml:lang="en-US" id="id_9887657_1710687_1_1">Marketable Securities Maturity Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_MarketableSecuritiesMaturityPeriod_lbl" xml:lang="en-US" id="id_9887657_1710687_2_1">Marketable securities, Maturity period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_MarketableSecuritiesMaturityPeriod" xlink:to="aos_MarketableSecuritiesMaturityPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MarketableSecuritiesPolicy" xlink:label="us-gaap_MarketableSecuritiesPolicy"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MarketableSecuritiesPolicy_lbl" xml:lang="en-US" id="id_9887657_1559010_1_1">Marketable Securities, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MarketableSecuritiesPolicy_lbl" xml:lang="en-US" id="id_9887657_1559010_2_1">Marketable securities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MarketableSecuritiesPolicy" xlink:to="us-gaap_MarketableSecuritiesPolicy_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_MaximumAggregateProductLiabilityInsuranceCoverage" xlink:label="aos_MaximumAggregateProductLiabilityInsuranceCoverage"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_MaximumAggregateProductLiabilityInsuranceCoverage_lbl" xml:lang="en-US" id="id_9887657_1696160_3_1">Maximum aggregate amount of third party product liability insurance coverage for individual losses in excess of a specified amount.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_MaximumAggregateProductLiabilityInsuranceCoverage_lbl" xml:lang="en-US" id="id_9887657_1696160_1_1">Maximum Aggregate Product Liability Insurance Coverage</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_MaximumAggregateProductLiabilityInsuranceCoverage_lbl" xml:lang="en-US" id="id_9887657_1696160_2_1">Product liability insurance for individual losses in excess of accrual amount</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_MaximumAggregateProductLiabilityInsuranceCoverage" xlink:to="aos_MaximumAggregateProductLiabilityInsuranceCoverage_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MaximumMember" xlink:label="us-gaap_MaximumMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US" id="id_9887657_1552364_1_1">Maximum [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MaximumMember_lbl" xml:lang="en-US" id="id_9887657_1552364_2_1">Maximum</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MaximumMember" xlink:to="us-gaap_MaximumMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MinimumMember" xlink:label="us-gaap_MinimumMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US" id="id_9887657_1555723_1_1">Minimum [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MinimumMember_lbl" xml:lang="en-US" id="id_9887657_1555723_2_1">Minimum</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinimumMember" xlink:to="us-gaap_MinimumMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits" xlink:label="aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits_lbl" xml:lang="en-US" id="id_9887657_1638013_3_1">Minimum Percentage Of Amount Likely To Be Realized Upon Ultimate Settlement To Recognize Tax Benefits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits_lbl" xml:lang="en-US" id="id_9887657_1638013_1_1">Minimum Percentage Of Amount Likely To Be Realized Upon Ultimate Settlement To Recognize Tax Benefits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits_lbl" xml:lang="en-US" id="id_9887657_1638013_2_1">Minimum percentage of amount likely to be realized upon ultimate settlement to recognize tax benefits</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits" xlink:to="aos_MinimumPercentageOfAmountLikelyToBeRealizedUponUltimateSettlementToRecognizeTaxBenefits_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_MutualFundMember" xlink:label="us-gaap_MutualFundMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_MutualFundMember_lbl" xml:lang="en-US" id="id_9887657_1555777_1_1">Mutual Fund [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_MutualFundMember_lbl" xml:lang="en-US" id="id_9887657_1555777_2_1">Mutual Fund</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MutualFundMember" xlink:to="us-gaap_MutualFundMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/currency/2017/currency-2017-01-31.xsd#currency_MXN" xlink:label="currency_MXN"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="currency_MXN_lbl" xml:lang="en-US" id="id_9887657_1549178_1_1">Mexico, Pesos</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="currency_MXN_lbl" xml:lang="en-US" id="id_9887657_1549178_2_1">Mexican peso</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="currency_MXN" xlink:to="currency_MXN_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NameOfMajorCustomerDomain" xlink:label="us-gaap_NameOfMajorCustomerDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NameOfMajorCustomerDomain_lbl" xml:lang="en-US" id="id_9887657_1552462_1_1">Customer [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NameOfMajorCustomerDomain_lbl" xml:lang="en-US" id="id_9887657_1552462_2_1">Customer [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NameOfMajorCustomerDomain" xlink:to="us-gaap_NameOfMajorCustomerDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations_lbl" xml:lang="en-US" id="id_9887657_1566883_1_1">Net Cash Provided by (Used in) Financing Activities, Continuing Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations_lbl" xml:lang="en-US" id="id_9887657_1566883_6_1">Cash Used in Financing Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_lbl" xml:lang="en-US" id="id_9887657_1552479_1_1">Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract_lbl" xml:lang="en-US" id="id_9887657_1552479_2_1">Financing Activities</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations_lbl" xml:lang="en-US" id="id_9887657_1564875_1_1">Net Cash Provided by (Used in) Investing Activities, Continuing Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations_lbl" xml:lang="en-US" id="id_9887657_1564875_6_1">Cash Used in Investing Activities</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_lbl" xml:lang="en-US" id="id_9887657_1552480_1_1">Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_lbl" xml:lang="en-US" id="id_9887657_1549194_1_1">Net Cash Provided by (Used in) Operating Activities, Continuing Operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_lbl" xml:lang="en-US" id="id_9887657_1549194_6_1">Cash Provided by Operating Activities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="us-gaap_NetIncomeLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561938_1_1">Net Income (Loss) Attributable to Parent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561938_2_1">Earnings from continuing operations</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561938_6_1">Net Earnings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_NetIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561938_12_1">Net earnings</label>
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    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NetOperatingLossesAndTaxCredits" xlink:label="aos_NetOperatingLossesAndTaxCredits"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NetOperatingLossesAndTaxCredits_lbl" xml:lang="en-US" id="id_9887657_1655116_3_1">Net operating losses and tax credits.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NetOperatingLossesAndTaxCredits_lbl" xml:lang="en-US" id="id_9887657_1655116_1_1">Net Operating Losses And Tax Credits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="aos_NetOperatingLossesAndTaxCredits_lbl" xml:lang="en-US" id="id_9887657_1655116_4_1">Net Operating Losses and Tax Credits, Ending balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="aos_NetOperatingLossesAndTaxCredits_lbl" xml:lang="en-US" id="id_9887657_1655116_5_1">Net Operating Losses and Tax Credits, Beginning balance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NetOperatingLossesAndTaxCredits" xlink:to="aos_NetOperatingLossesAndTaxCredits_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NetOperatingLossesAndTaxCreditsAdditions" xlink:label="aos_NetOperatingLossesAndTaxCreditsAdditions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NetOperatingLossesAndTaxCreditsAdditions_lbl" xml:lang="en-US" id="id_9887657_1676582_3_1">Net operating losses and tax credits, additions.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NetOperatingLossesAndTaxCreditsAdditions_lbl" xml:lang="en-US" id="id_9887657_1676582_1_1">Net Operating Losses And Tax Credits Additions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_NetOperatingLossesAndTaxCreditsAdditions_lbl" xml:lang="en-US" id="id_9887657_1676582_2_1">Net Operating Losses and Tax Credits, Additions</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NetOperatingLossesAndTaxCreditsAdditions" xlink:to="aos_NetOperatingLossesAndTaxCreditsAdditions_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NetOperatingLossesAndTaxCreditsDeductions" xlink:label="aos_NetOperatingLossesAndTaxCreditsDeductions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NetOperatingLossesAndTaxCreditsDeductions_lbl" xml:lang="en-US" id="id_9887657_1624963_3_1">Net Operating Losses And Tax Credits, Deductions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NetOperatingLossesAndTaxCreditsDeductions_lbl" xml:lang="en-US" id="id_9887657_1624963_1_1">Net Operating Losses And Tax Credits Deductions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="aos_NetOperatingLossesAndTaxCreditsDeductions_lbl" xml:lang="en-US" id="id_9887657_1624963_14_1">Net Operating Losses and Tax Credits, Reductions</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NetOperatingLossesAndTaxCreditsDeductions" xlink:to="aos_NetOperatingLossesAndTaxCreditsDeductions_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1549205_1_1">New Accounting Pronouncements, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1549205_2_1">Recent Accounting Pronouncements</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NoncurrentAssets" xlink:label="us-gaap_NoncurrentAssets"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NoncurrentAssets_lbl" xml:lang="en-US" id="id_9887657_1566886_1_1">Long-Lived Assets</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NoncurrentAssets_lbl" xml:lang="en-US" id="id_9887657_1566886_2_1">Long-lived Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NoncurrentAssets" xlink:to="us-gaap_NoncurrentAssets_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NorthAmericaSegmentMember" xlink:label="aos_NorthAmericaSegmentMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NorthAmericaSegmentMember_lbl" xml:lang="en-US" id="id_9887657_1602171_3_1">North America Segment [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NorthAmericaSegmentMember_lbl" xml:lang="en-US" id="id_9887657_1602171_1_1">North America Segment [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_NorthAmericaSegmentMember_lbl" xml:lang="en-US" id="id_9887657_1602171_2_1">North America</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NorthAmericaSegmentMember" xlink:to="aos_NorthAmericaSegmentMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NotesPayable" xlink:label="us-gaap_NotesPayable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesPayable_lbl" xml:lang="en-US" id="id_9887657_1562796_1_1">Notes Payable</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesPayable_lbl" xml:lang="en-US" id="id_9887657_1562796_2_1">Carrying amount of term notes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayable" xlink:to="us-gaap_NotesPayable_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NotesPayableFairValueDisclosure" xlink:label="us-gaap_NotesPayableFairValueDisclosure"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NotesPayableFairValueDisclosure_lbl" xml:lang="en-US" id="id_9887657_1563734_1_1">Notes Payable, Fair Value Disclosure</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NotesPayableFairValueDisclosure_lbl" xml:lang="en-US" id="id_9887657_1563734_2_1">Fair value of term notes</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableFairValueDisclosure" xlink:to="us-gaap_NotesPayableFairValueDisclosure_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember" xlink:label="aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember_lbl" xml:lang="en-US" id="id_9887657_1656595_3_1">November Twenty Sixteen Term Notes with Insurance Companies [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember_lbl" xml:lang="en-US" id="id_9887657_1656595_1_1">November Twenty Sixteen Term Notes with Insurance Companies [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember_lbl" xml:lang="en-US" id="id_9887657_1656595_2_1">November 2016 Term Notes with Insurance Companies</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember" xlink:to="aos_NovemberTwentySixteenTermNotesWithInsuranceCompaniesMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement" xlink:label="aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement_lbl" xml:lang="en-US" id="id_9887657_1659346_3_1">Number Of Banks Involved In Multi-Year Multi-Currency Revolving Credit Agreement</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement_lbl" xml:lang="en-US" id="id_9887657_1659346_1_1">Number Of Banks Involved In Multi Year Multi Currency Revolving Credit Agreement</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement_lbl" xml:lang="en-US" id="id_9887657_1659346_2_1">Number of banks involved in multi-year multi-currency revolving credit agreement</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement" xlink:to="aos_NumberOfBanksInvolvedInMultiYearMultiCurrencyRevolvingCreditAgreement_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:label="us-gaap_NumberOfReportableSegments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US" id="id_9887657_1559167_1_1">Number of Reportable Segments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xml:lang="en-US" id="id_9887657_1559167_2_1">Number of reporting segments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_NumberOfTranches" xlink:label="aos_NumberOfTranches"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_NumberOfTranches_lbl" xml:lang="en-US" id="id_9887657_1700798_3_1">Number of Tranches</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_NumberOfTranches_lbl" xml:lang="en-US" id="id_9887657_1700798_1_1">Number of Tranches</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_NumberOfTranches_lbl" xml:lang="en-US" id="id_9887657_1700798_2_1">Debt instrument, number of tranches</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_NumberOfTranches" xlink:to="aos_NumberOfTranches_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent" xlink:label="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_lbl" xml:lang="en-US" id="id_9887657_1561045_1_1">OCI, before Reclassifications, Net of Tax, Attributable to Parent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_lbl" xml:lang="en-US" id="id_9887657_1561045_2_1">Other comprehensive gain (loss) before reclassifications</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent" xlink:to="us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="us-gaap_OperatingIncomeLoss"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561916_1_1">Operating Income (Loss)</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561916_2_1">Operating earnings</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xml:lang="en-US" id="id_9887657_1561916_12_1">Segment earnings</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingIncomeLoss" xlink:to="us-gaap_OperatingIncomeLoss_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US" id="id_9887657_1561032_1_1">Operating Leases, Future Minimum Payments Due</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl" xml:lang="en-US" id="id_9887657_1561032_2_1">Future minimum payments under non-cancelable operating leases due, total</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_lbl" xml:lang="en-US" id="id_9887657_1552576_1_1">Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_lbl" xml:lang="en-US" id="id_9887657_1552576_2_1">Debt And Lease Commitments [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" xml:lang="en-US" id="id_9887657_1561912_1_1">Operating Leases, Future Minimum Payments Due, Next Twelve Months</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent_lbl" xml:lang="en-US" id="id_9887657_1561912_2_1">2018</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" xml:lang="en-US" id="id_9887657_1562786_1_1">Operating Leases, Future Minimum Payments, Due in Three Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears_lbl" xml:lang="en-US" id="id_9887657_1562786_2_1">2020</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" xml:lang="en-US" id="id_9887657_1561034_1_1">Operating Leases, Future Minimum Payments, Due in Two Years</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears_lbl" xml:lang="en-US" id="id_9887657_1561034_2_1">2019</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" xml:lang="en-US" id="id_9887657_1563728_1_1">Operating Leases, Future Minimum Payments, Due Thereafter</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter_lbl" xml:lang="en-US" id="id_9887657_1563728_2_1">Thereafter</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xml:lang="en-US" id="id_9887657_1552593_1_1">Operating Segments [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xml:lang="en-US" id="id_9887657_1552593_2_1">Operating Segments</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingSegmentsMember" xlink:to="us-gaap_OperatingSegmentsMember_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems_lbl" xml:lang="en-US" id="id_9887657_1712310_3_1">Organization And Summary Of Significant Accounting Policies [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems_lbl" xml:lang="en-US" id="id_9887657_1712310_1_1">Organization And Summary Of Significant Accounting Policies [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesLineItems_lbl" xml:lang="en-US" id="id_9887657_1712310_2_1">Organization And Summary Of Significant Accounting Policies [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl" xml:lang="en-US" id="id_9887657_1636363_3_1">Organization And Summary Of Significant Accounting Policies [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl" xml:lang="en-US" id="id_9887657_1636363_1_1">Organization And Summary Of Significant Accounting Policies [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl" xml:lang="en-US" id="id_9887657_1636363_2_1">Organization And Summary Of Significant Accounting Policies [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesTable" xlink:to="aos_OrganizationAndSummaryOfSignificantAccountingPoliciesTable_lbl"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1567894_2_1">Other assets</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax_lbl" xml:lang="en-US" id="id_9887657_1561890_14_1">Other changes in plan assets and projected benefit obligation recognized in other comprehensive loss Net actuarial (gain) loss</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_OtherComprehensiveIncomeLossMinimumPensionLiabilityNetAdjustmentTaxEffect_lbl" xml:lang="en-US" id="id_9887657_1699790_1_1">Other Comprehensive Income (Loss), Minimum Pension Liability Net Adjustment, Tax Effect</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:label="us-gaap_PaymentsToAcquireMarketableSecurities"/>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PaymentsToAcquireMarketableSecurities_lbl" xml:lang="en-US" id="id_9887657_1561814_14_1">Investments in marketable securities</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PaymentsToAcquireProductiveAssets_lbl" xml:lang="en-US" id="id_9887657_1561817_2_1">Capital expenditures</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PensionAndOtherPostretirementBenefitsDisclosureLineItems_lbl" xml:lang="en-US" id="id_9887657_1613306_3_1">Pension and Other Postretirement Benefits Disclosure [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PensionAndOtherPostretirementBenefitsDisclosureLineItems_lbl" xml:lang="en-US" id="id_9887657_1613306_1_1">Pension and Other Postretirement Benefits Disclosure [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PensionAndOtherPostretirementBenefitsDisclosureTable_lbl" xml:lang="en-US" id="id_9887657_1660163_3_1">Pension and Other Postretirement Benefits Disclosure [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PensionAndOtherPostretirementBenefitsDisclosureTable_lbl" xml:lang="en-US" id="id_9887657_1660163_1_1">Pension and Other Postretirement Benefits Disclosure [Table]</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1562666_1_1">Liability, Defined Benefit Plan</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1562666_2_1">Liability on foreign pension plan</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1562666_19_1">Net pension liability at end of year</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1563613_1_1">Liability, Defined Benefit Plan, Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1563613_14_1">Non-current liabilities</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PensionContributions" xlink:label="us-gaap_PensionContributions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionContributions_lbl" xml:lang="en-US" id="id_9887657_1561802_1_1">Payment for Pension Benefits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionContributions_lbl" xml:lang="en-US" id="id_9887657_1561802_2_1">Voluntary pension contribution</label>
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    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_PensionExpenseIncome" xlink:label="aos_PensionExpenseIncome"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PensionExpenseIncome_lbl" xml:lang="en-US" id="id_9887657_1696185_3_1">The amount of pension benefit costs or benefits recognized during the period for defined benefit plans For defined benefit plans, pension expense income includes the following components: service cost, interest cost, expected return on plan assets, gain (loss) on plan assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PensionExpenseIncome_lbl" xml:lang="en-US" id="id_9887657_1696185_1_1">Pension Expense Income</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="aos_PensionExpenseIncome_lbl" xml:lang="en-US" id="id_9887657_1696185_14_1">Pension (income) expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_PensionExpenseIncome" xlink:to="aos_PensionExpenseIncome_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="us-gaap_PensionPlansDefinedBenefitMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PensionPlansDefinedBenefitMember_lbl" xml:lang="en-US" id="id_9887657_1552705_1_1">Pension Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PensionPlansDefinedBenefitMember_lbl" xml:lang="en-US" id="id_9887657_1552705_2_1">Pension Plans, Defined Benefit</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PensionPlansDefinedBenefitMember" xlink:to="us-gaap_PensionPlansDefinedBenefitMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees" xlink:label="aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees_lbl" xml:lang="en-US" id="id_9887657_1615445_3_1">Percentage match of the first one percent of contributions made by participating employees.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees_lbl" xml:lang="en-US" id="id_9887657_1615445_1_1">Percentage Match Of First One Percent Of Contributions Made By Participating Employees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees_lbl" xml:lang="en-US" id="id_9887657_1615445_2_1">Percentage match of the first one percent of contributions made by participating employees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees" xlink:to="aos_PercentageMatchOfFirstOnePercentOfContributionsMadeByParticipatingEmployees_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees" xlink:label="aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees_lbl" xml:lang="en-US" id="id_9887657_1662931_3_1">Percentage Match Of The Next Five Percent Of Contributions Made By Participating Employees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees_lbl" xml:lang="en-US" id="id_9887657_1662931_1_1">Percentage Match Of Next Five Percent Of Contributions Made By Participating Employees</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees_lbl" xml:lang="en-US" id="id_9887657_1662931_2_1">Percentage Match Of The Next Five Percent Of Contributions Made By Participating Employees</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees" xlink:to="aos_PercentageMatchOfNextFivePercentOfContributionsMadeByParticipatingEmployees_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PercentageOfLIFOInventory" xlink:label="us-gaap_PercentageOfLIFOInventory"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PercentageOfLIFOInventory_lbl" xml:lang="en-US" id="id_9887657_1556013_1_1">Percentage of LIFO Inventory</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PercentageOfLIFOInventory_lbl" xml:lang="en-US" id="id_9887657_1556013_2_1">Percentage of (LIFO) inventory</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PercentageOfLIFOInventory" xlink:to="us-gaap_PercentageOfLIFOInventory_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_PercentageOfStockDividendToStockHolders" xlink:label="aos_PercentageOfStockDividendToStockHolders"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PercentageOfStockDividendToStockHolders_lbl" xml:lang="en-US" id="id_9887657_1693648_3_1">Percentage of stock dividend to stock holders.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PercentageOfStockDividendToStockHolders_lbl" xml:lang="en-US" id="id_9887657_1693648_1_1">Percentage Of Stock Dividend To Stock Holders</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_PercentageOfStockDividendToStockHolders_lbl" xml:lang="en-US" id="id_9887657_1693648_2_1">Percentage of stock dividend to stock holders</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_PercentageOfStockDividendToStockHolders" xlink:to="aos_PercentageOfStockDividendToStockHolders_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PlanAssetCategoriesDomain" xlink:label="us-gaap_PlanAssetCategoriesDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanAssetCategoriesDomain_lbl" xml:lang="en-US" id="id_9887657_1559323_1_1">Plan Asset Categories [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PlanAssetCategoriesDomain_lbl" xml:lang="en-US" id="id_9887657_1559323_2_1">Plan Asset Categories [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanAssetCategoriesDomain" xlink:to="us-gaap_PlanAssetCategoriesDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="us-gaap_PlanNameAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameAxis_lbl" xml:lang="en-US" id="id_9887657_1549394_1_1">Plan Name [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PlanNameAxis_lbl" xml:lang="en-US" id="id_9887657_1549394_2_1">Plan Name [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="us-gaap_PlanNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PlanNameDomain_lbl" xml:lang="en-US" id="id_9887657_1559324_1_1">Plan Name [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PlanNameDomain_lbl" xml:lang="en-US" id="id_9887657_1559324_2_1">Plan Name [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PositionAxis" xlink:label="us-gaap_PositionAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PositionAxis_lbl" xml:lang="en-US" id="id_9887657_1556034_1_1">Position [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PositionAxis_lbl" xml:lang="en-US" id="id_9887657_1556034_2_1">Position [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PositionAxis" xlink:to="us-gaap_PositionAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PositionDomain" xlink:label="us-gaap_PositionDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PositionDomain_lbl" xml:lang="en-US" id="id_9887657_1559335_1_1">Position [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PositionDomain_lbl" xml:lang="en-US" id="id_9887657_1559335_2_1">Position [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PositionDomain" xlink:to="us-gaap_PositionDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_PostretirementMedicalBenefitsQualifyingAge" xlink:label="aos_PostretirementMedicalBenefitsQualifyingAge"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PostretirementMedicalBenefitsQualifyingAge_lbl" xml:lang="en-US" id="id_9887657_1652607_3_1">Postretirement Medical Benefits Qualifying Age</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PostretirementMedicalBenefitsQualifyingAge_lbl" xml:lang="en-US" id="id_9887657_1652607_1_1">Postretirement Medical Benefits Qualifying Age</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_PostretirementMedicalBenefitsQualifyingAge_lbl" xml:lang="en-US" id="id_9887657_1652607_2_1">Medical and life insurance maximum participant coverage age, in years</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_PostretirementMedicalBenefitsQualifyingAge" xlink:to="aos_PostretirementMedicalBenefitsQualifyingAge_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xml:lang="en-US" id="id_9887657_1559359_1_1">Preferred Stock, Par or Stated Value Per Share</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xml:lang="en-US" id="id_9887657_1559359_2_1">Preferred stock, par value</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockParOrStatedValuePerShare" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="us-gaap_PreferredStockSharesAuthorized"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xml:lang="en-US" id="id_9887657_1559360_1_1">Preferred Stock, Shares Authorized</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xml:lang="en-US" id="id_9887657_1559360_2_1">Preferred stock, shares authorized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockSharesAuthorized" xlink:to="us-gaap_PreferredStockSharesAuthorized_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="us-gaap_PreferredStockValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PreferredStockValue_lbl" xml:lang="en-US" id="id_9887657_1560899_1_1">Preferred Stock, Value, Issued</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PreferredStockValue_lbl" xml:lang="en-US" id="id_9887657_1560899_2_1">Preferred Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PreferredStockValue" xlink:to="us-gaap_PreferredStockValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription_lbl" xml:lang="en-US" id="id_9887657_1549436_1_1">Reclassification, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PriorPeriodReclassificationAdjustmentDescription_lbl" xml:lang="en-US" id="id_9887657_1549436_2_1">Reclassifications</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PriorPeriodReclassificationAdjustmentDescription" xlink:to="us-gaap_PriorPeriodReclassificationAdjustmentDescription_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_PrivateEquityMember" xlink:label="aos_PrivateEquityMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_PrivateEquityMember_lbl" xml:lang="en-US" id="id_9887657_1574911_3_1">Private Equity [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_PrivateEquityMember_lbl" xml:lang="en-US" id="id_9887657_1574911_1_1">Private Equity [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_PrivateEquityMember_lbl" xml:lang="en-US" id="id_9887657_1574911_2_1">Private equity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_PrivateEquityMember" xlink:to="aos_PrivateEquityMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl" xml:lang="en-US" id="id_9887657_1568011_1_1">Proceeds from Issuance of Long-term Debt</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl" xml:lang="en-US" id="id_9887657_1568011_2_1">Long-term debt incurred</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfLongTermDebt_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl" xml:lang="en-US" id="id_9887657_1566070_1_1">Proceeds from Sale and Maturity of Marketable Securities</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl" xml:lang="en-US" id="id_9887657_1566070_2_1">Proceeds from sales of marketable securities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_ProceedsFromStockOptionsActivity" xlink:label="aos_ProceedsFromStockOptionsActivity"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_ProceedsFromStockOptionsActivity_lbl" xml:lang="en-US" id="id_9887657_1619739_3_1">The cash inflow associated with the amount received from holders exercising their stock options. This item is net of cash paid by the employer to a taxing authority when shares are directly withheld for employee income tax purposes.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_ProceedsFromStockOptionsActivity_lbl" xml:lang="en-US" id="id_9887657_1619739_1_1">Proceeds From Stock Options Activity</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_ProceedsFromStockOptionsActivity_lbl" xml:lang="en-US" id="id_9887657_1619739_2_1">Net (payments) proceeds from stock option activity</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_ProceedsFromStockOptionsActivity" xlink:to="aos_ProceedsFromStockOptionsActivity_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_ProductLiabilityIndividualClaimMaximumAmount" xlink:label="aos_ProductLiabilityIndividualClaimMaximumAmount"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_ProductLiabilityIndividualClaimMaximumAmount_lbl" xml:lang="en-US" id="id_9887657_1711602_3_1">Maximum amount self insured by the company for an individual product liability claim. Amounts in excess to be covered by third party insurance.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_ProductLiabilityIndividualClaimMaximumAmount_lbl" xml:lang="en-US" id="id_9887657_1711602_1_1">Product Liability Individual Claim Maximum Amount</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_ProductLiabilityIndividualClaimMaximumAmount_lbl" xml:lang="en-US" id="id_9887657_1711602_2_1">Amounts in excess to be covered by third party insurance</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_ProductLiabilityIndividualClaimMaximumAmount" xlink:to="aos_ProductLiabilityIndividualClaimMaximumAmount_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantiesDisclosuresAbstract" xlink:label="us-gaap_ProductWarrantiesDisclosuresAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantiesDisclosuresAbstract_lbl" xml:lang="en-US" id="id_9887657_1552826_1_1">Product Warranties Disclosures [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductWarrantiesDisclosuresAbstract_lbl" xml:lang="en-US" id="id_9887657_1552826_2_1">Product Warranties</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantiesDisclosuresAbstract" xlink:to="us-gaap_ProductWarrantiesDisclosuresAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyAccrual" xlink:label="us-gaap_ProductWarrantyAccrual"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xml:lang="en-US" id="id_9887657_1560888_1_1">Standard and Extended Product Warranty Accrual</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xml:lang="en-US" id="id_9887657_1560888_4_1">Balance at end of year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ProductWarrantyAccrual_lbl" xml:lang="en-US" id="id_9887657_1560888_5_1">Balance at beginning of year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyAccrual" xlink:to="us-gaap_ProductWarrantyAccrual_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyAccrualClassifiedCurrent" xlink:label="us-gaap_ProductWarrantyAccrualClassifiedCurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyAccrualClassifiedCurrent_lbl" xml:lang="en-US" id="id_9887657_1563577_1_1">Product Warranty Accrual, Current</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductWarrantyAccrualClassifiedCurrent_lbl" xml:lang="en-US" id="id_9887657_1563577_2_1">Product warranties</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyAccrualClassifiedCurrent" xlink:to="us-gaap_ProductWarrantyAccrualClassifiedCurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyAccrualNoncurrent" xlink:label="us-gaap_ProductWarrantyAccrualNoncurrent"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyAccrualNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1561776_1_1">Product Warranty Accrual, Noncurrent</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductWarrantyAccrualNoncurrent_lbl" xml:lang="en-US" id="id_9887657_1561776_2_1">Product warranties</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyAccrualNoncurrent" xlink:to="us-gaap_ProductWarrantyAccrualNoncurrent_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyAccrualPayments" xlink:label="us-gaap_ProductWarrantyAccrualPayments"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyAccrualPayments_lbl" xml:lang="en-US" id="id_9887657_1568062_1_1">Standard and Extended Product Warranty Accrual, Decrease for Payments</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ProductWarrantyAccrualPayments_lbl" xml:lang="en-US" id="id_9887657_1568062_14_1">Claims settled</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyAccrualPayments" xlink:to="us-gaap_ProductWarrantyAccrualPayments_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyExpense" xlink:label="us-gaap_ProductWarrantyExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyExpense_lbl" xml:lang="en-US" id="id_9887657_1567077_1_1">Product Warranty Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductWarrantyExpense_lbl" xml:lang="en-US" id="id_9887657_1567077_2_1">Expense</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyExpense" xlink:to="us-gaap_ProductWarrantyExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyLiabilityLineItems" xlink:label="us-gaap_ProductWarrantyLiabilityLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyLiabilityLineItems_lbl" xml:lang="en-US" id="id_9887657_1552828_1_1">Product Warranty Liability [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductWarrantyLiabilityLineItems_lbl" xml:lang="en-US" id="id_9887657_1552828_2_1">Product Warranty Liability [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyLiabilityLineItems" xlink:to="us-gaap_ProductWarrantyLiabilityLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ProductWarrantyLiabilityTable" xlink:label="us-gaap_ProductWarrantyLiabilityTable"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ProductWarrantyLiabilityTable_lbl" xml:lang="en-US" id="id_9887657_1549466_1_1">Product Warranty Liability [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ProductWarrantyLiabilityTable_lbl" xml:lang="en-US" id="id_9887657_1549466_2_1">Product Warranty Liability [Table]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProductWarrantyLiabilityTable" xlink:to="us-gaap_ProductWarrantyLiabilityTable_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_ProductWarrantyPeriod" xlink:label="aos_ProductWarrantyPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_ProductWarrantyPeriod_lbl" xml:lang="en-US" id="id_9887657_1646975_3_1">Product Warranty Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_ProductWarrantyPeriod_lbl" xml:lang="en-US" id="id_9887657_1646975_1_1">Product Warranty Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_ProductWarrantyPeriod_lbl" xml:lang="en-US" id="id_9887657_1646975_2_1">Product warranty period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_ProductWarrantyPeriod" xlink:to="aos_ProductWarrantyPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xml:lang="en-US" id="id_9887657_1552818_1_1">Property, Plant and Equipment [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xml:lang="en-US" id="id_9887657_1552818_2_1">Property, Plant and Equipment [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1559426_1_1">Property, Plant and Equipment, Type [Axis]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xml:lang="en-US" id="id_9887657_1559426_2_1">Property, Plant and Equipment, Type [Axis]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1556094_1_1">Property, Plant and Equipment Disclosure [Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl" xml:lang="en-US" id="id_9887657_1556094_2_1">Property, Plant and Equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="us-gaap_PropertyPlantAndEquipmentGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xml:lang="en-US" id="id_9887657_1567082_1_1">Property, Plant and Equipment, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xml:lang="en-US" id="id_9887657_1567082_2_1">Property, plant and equipment, gross</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentGross" xlink:to="us-gaap_PropertyPlantAndEquipmentGross_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xml:lang="en-US" id="id_9887657_1556105_1_1">Property, Plant and Equipment [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xml:lang="en-US" id="id_9887657_1556105_2_1">Property, Plant and Equipment [Line Items]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="us-gaap_PropertyPlantAndEquipmentNet"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US" id="id_9887657_1565076_1_1">Property, Plant and Equipment, Net</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US" id="id_9887657_1565076_2_1">Net property, plant and equipment</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xml:lang="en-US" id="id_9887657_1565076_6_1">Net property, plant and equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNet" xlink:to="us-gaap_PropertyPlantAndEquipmentNet_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract" xlink:label="us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_lbl" xml:lang="en-US" id="id_9887657_1556106_1_1">Property, Plant and Equipment, Net, by Type [Abstract]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_lbl" xml:lang="en-US" id="id_9887657_1556106_2_1">Property, Plant and Equipment, Net, by Type [Abstract]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNetByTypeAbstract_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1559432_1_1">Property, Plant and Equipment, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl" xml:lang="en-US" id="id_9887657_1559432_2_1">Property, plant and equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xml:lang="en-US" id="id_9887657_1552831_1_1">Property, Plant and Equipment [Table Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl" xml:lang="en-US" id="id_9887657_1552831_2_1">Schedule of Property Plant and Equipment</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock_lbl"/>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xml:lang="en-US" id="id_9887657_1566168_1_1">Selling, General and Administrative Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SellingGeneralAndAdministrativeExpense_lbl" xml:lang="en-US" id="id_9887657_1566168_2_1">Selling, general and administrative expenses</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_SeventeenPointFourSixToTwentyFivePointThreeFourMember_lbl" xml:lang="en-US" id="id_9887657_1579995_3_1">Seventeen Point Four Six to Twenty Five Point Three Four [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_SeventeenPointFourSixToTwentyFivePointThreeFourMember_lbl" xml:lang="en-US" id="id_9887657_1579995_1_1">Seventeen Point Four Six to Twenty Five Point Three Four [Member]</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_lbl" xml:lang="en-US" id="id_9887657_1565175_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1_lbl" xml:lang="en-US" id="id_9887657_1565175_2_1">Aggregate intrinsic value for the exercisable options</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xml:lang="en-US" id="id_9887657_1556521_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xml:lang="en-US" id="id_9887657_1556521_2_1">Exercisable at End of Period</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1556522_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1556522_2_1">Weighted-Avg. Per Share Exercisable Price, ending period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" xml:lang="en-US" id="id_9887657_1553242_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" xml:lang="en-US" id="id_9887657_1553242_2_1">Average remaining contractual life for exercisable options, in years</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xml:lang="en-US" id="id_9887657_1567168_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl" xml:lang="en-US" id="id_9887657_1567168_2_1">Aggregate Intrinsic Value, Exercised at end of Period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xml:lang="en-US" id="id_9887657_1553243_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xml:lang="en-US" id="id_9887657_1553243_14_1">Forfeited</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl" xml:lang="en-US" id="id_9887657_1559851_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl" xml:lang="en-US" id="id_9887657_1559851_2_1">Number of Options, granted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xml:lang="en-US" id="id_9887657_1556525_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xml:lang="en-US" id="id_9887657_1556525_2_1">Granted</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US" id="id_9887657_1553244_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xml:lang="en-US" id="id_9887657_1553244_2_1">Weighted-average fair value per option at the date of grant</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xml:lang="en-US" id="id_9887657_1568182_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xml:lang="en-US" id="id_9887657_1568182_2_1">Aggregate intrinsic value for the outstanding options</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US" id="id_9887657_1556527_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US" id="id_9887657_1556527_4_1">Outstanding, Ending Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US" id="id_9887657_1556527_5_1">Outstanding, Beginning Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xml:lang="en-US" id="id_9887657_1556527_2_1">Number of Options, outstanding</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1556529_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1556529_4_1">Weighted-Avg. Per Share Exercise Price, ending period</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1556529_5_1">Weighted-Avg. Per Share Exercise Price, beginning period</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US" id="id_9887657_1549872_1_1">Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl" xml:lang="en-US" id="id_9887657_1549872_2_1">Average remaining contractual life for outstanding options, in years</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US" id="id_9887657_1549884_1_1">Equity Award [Domain]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xml:lang="en-US" id="id_9887657_1549884_2_1">Equity Award [Domain]</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1549885_1_1">Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1549885_2_1">Weighted-Avg. Per Share Exercise Price - Exercised</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1553211_1_1">Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_lbl" xml:lang="en-US" id="id_9887657_1553211_2_1">Weighted-Avg. Per Share Exercise Price - Forfeited</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_StockholdersEquityLineItems_lbl" xml:lang="en-US" id="id_9887657_1596596_3_1">Stockholders Equity [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_StockholdersEquityLineItems_lbl" xml:lang="en-US" id="id_9887657_1596596_1_1">Stockholders Equity [Line Items]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_StockholdersEquityLineItems_lbl" xml:lang="en-US" id="id_9887657_1596596_2_1">Stockholders Equity [Line Items]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_StockholdersEquityTable_lbl" xml:lang="en-US" id="id_9887657_1700208_3_1">Stockholders' Equity [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_StockholdersEquityTable_lbl" xml:lang="en-US" id="id_9887657_1700208_1_1">Stockholders' Equity [Table]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_StockholdersEquityTable_lbl" xml:lang="en-US" id="id_9887657_1700208_2_1">Stockholders' Equity [Table]</label>
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    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US" id="id_9887657_1550084_1_1">Trading Symbol</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="dei_TradingSymbol_lbl" xml:lang="en-US" id="id_9887657_1550084_2_1">Trading Symbol</label>
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    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TreasuryStockMember" xlink:label="us-gaap_TreasuryStockMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockMember_lbl" xml:lang="en-US" id="id_9887657_1553449_1_1">Treasury Stock [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TreasuryStockMember_lbl" xml:lang="en-US" id="id_9887657_1553449_2_1">Treasury Stock</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockMember" xlink:to="us-gaap_TreasuryStockMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TreasuryStockShares" xlink:label="us-gaap_TreasuryStockShares"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US" id="id_9887657_1550096_1_1">Treasury Stock, Shares</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TreasuryStockShares_lbl" xml:lang="en-US" id="id_9887657_1550096_2_1">Treasury stock, number of shares held</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockShares" xlink:to="us-gaap_TreasuryStockShares_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:label="us-gaap_TreasuryStockSharesAcquired"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockSharesAcquired_lbl" xml:lang="en-US" id="id_9887657_1553425_1_1">Treasury Stock, Shares, Acquired</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TreasuryStockSharesAcquired_lbl" xml:lang="en-US" id="id_9887657_1553425_2_1">Shares repurchased</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockSharesAcquired" xlink:to="us-gaap_TreasuryStockSharesAcquired_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TreasuryStockValue" xlink:label="us-gaap_TreasuryStockValue"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US" id="id_9887657_1568215_1_1">Treasury Stock, Value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_TreasuryStockValue_lbl" xml:lang="en-US" id="id_9887657_1568215_14_1">Treasury stock at cost</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValue" xlink:to="us-gaap_TreasuryStockValue_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xml:lang="en-US" id="id_9887657_1567214_1_1">Treasury Stock, Value, Acquired, Cost Method</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xml:lang="en-US" id="id_9887657_1567214_2_1">Shares repurchased, value</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xml:lang="en-US" id="id_9887657_1567214_14_1">Shares repurchased</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:to="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_TwentyFiveYearPensionPlanMember" xlink:label="aos_TwentyFiveYearPensionPlanMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_TwentyFiveYearPensionPlanMember_lbl" xml:lang="en-US" id="id_9887657_1742686_3_1">Twenty Five Year Pension Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_TwentyFiveYearPensionPlanMember_lbl" xml:lang="en-US" id="id_9887657_1742686_1_1">Twenty Five Year Pension Plan [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_TwentyFiveYearPensionPlanMember_lbl" xml:lang="en-US" id="id_9887657_1742686_2_1">Twenty Five Year Pension Plan</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_TwentyFiveYearPensionPlanMember" xlink:to="aos_TwentyFiveYearPensionPlanMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_TwentySixPointFourSevenToFiftyPointOneSixMember" xlink:label="aos_TwentySixPointFourSevenToFiftyPointOneSixMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_TwentySixPointFourSevenToFiftyPointOneSixMember_lbl" xml:lang="en-US" id="id_9887657_1769058_3_1">Twenty six point four seven to fifty point one six.</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_TwentySixPointFourSevenToFiftyPointOneSixMember_lbl" xml:lang="en-US" id="id_9887657_1769058_1_1">Twenty Six Point Four Seven To Fifty Point One Six [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_TwentySixPointFourSevenToFiftyPointOneSixMember_lbl" xml:lang="en-US" id="id_9887657_1769058_2_1">$26.47 to $50.16</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_TwentySixPointFourSevenToFiftyPointOneSixMember" xlink:to="aos_TwentySixPointFourSevenToFiftyPointOneSixMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_TwoThousandFifteenMember" xlink:label="aos_TwoThousandFifteenMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_TwoThousandFifteenMember_lbl" xml:lang="en-US" id="id_9887657_1740724_3_1">Two Thousand Fifteen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_TwoThousandFifteenMember_lbl" xml:lang="en-US" id="id_9887657_1740724_1_1">Two Thousand Fifteen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_TwoThousandFifteenMember_lbl" xml:lang="en-US" id="id_9887657_1740724_2_1">Two Thousand Fifteen</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_TwoThousandFifteenMember" xlink:to="aos_TwoThousandFifteenMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_TwoThousandSeventeenMember" xlink:label="aos_TwoThousandSeventeenMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_TwoThousandSeventeenMember_lbl" xml:lang="en-US" id="id_9887657_1731526_3_1">Two Thousand Seventeen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_TwoThousandSeventeenMember_lbl" xml:lang="en-US" id="id_9887657_1731526_1_1">Two Thousand Seventeen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_TwoThousandSeventeenMember_lbl" xml:lang="en-US" id="id_9887657_1731526_2_1">Two Thousand Seventeen</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_TwoThousandSeventeenMember" xlink:to="aos_TwoThousandSeventeenMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_TwoThousandSixteenMember" xlink:label="aos_TwoThousandSixteenMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_TwoThousandSixteenMember_lbl" xml:lang="en-US" id="id_9887657_1607862_3_1">Two Thousand Sixteen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_TwoThousandSixteenMember_lbl" xml:lang="en-US" id="id_9887657_1607862_1_1">Two Thousand Sixteen [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_TwoThousandSixteenMember_lbl" xml:lang="en-US" id="id_9887657_1607862_2_1">Two Thousand Sixteen</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_TwoThousandSixteenMember" xlink:to="aos_TwoThousandSixteenMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefits" xlink:label="us-gaap_UnrecognizedTaxBenefits"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US" id="id_9887657_1562500_1_1">Unrecognized Tax Benefits</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US" id="id_9887657_1562500_4_1">Balance at December 31</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_UnrecognizedTaxBenefits_lbl" xml:lang="en-US" id="id_9887657_1562500_5_1">Balance at January 1</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefits" xlink:to="us-gaap_UnrecognizedTaxBenefits_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US" id="id_9887657_1563383_1_1">Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl" xml:lang="en-US" id="id_9887657_1563383_2_1">Additions for tax positions of prior years</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions" xlink:to="us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xml:lang="en-US" id="id_9887657_1560724_1_1">Unrecognized Tax Benefits that Would Impact Effective Tax Rate</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl" xml:lang="en-US" id="id_9887657_1560724_2_1">Unrecognized tax benefits that would affect the effective tax rate, if recognized</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate" xlink:to="us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.sec.gov/country/2017/country-2017-01-31.xsd#country_US" xlink:label="country_US"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="country_US_lbl" xml:lang="en-US" id="id_9887657_1560668_1_1">UNITED STATES</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="country_US_lbl" xml:lang="en-US" id="id_9887657_1560668_2_1">United States</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_US" xlink:to="country_US_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_UseOfEstimates" xlink:label="us-gaap_UseOfEstimates"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US" id="id_9887657_1557325_1_1">Use of Estimates, Policy [Policy Text Block]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_UseOfEstimates_lbl" xml:lang="en-US" id="id_9887657_1557325_2_1">Use of estimates</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UseOfEstimates" xlink:to="us-gaap_UseOfEstimates_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_USTreasurySecuritiesMember" xlink:label="us-gaap_USTreasurySecuritiesMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_USTreasurySecuritiesMember_lbl" xml:lang="en-US" id="id_9887657_1560669_1_1">US Treasury Securities [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_USTreasurySecuritiesMember_lbl" xml:lang="en-US" id="id_9887657_1560669_2_1">US Treasury Securities</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_USTreasurySecuritiesMember" xlink:to="us-gaap_USTreasurySecuritiesMember_lbl"/>
    <loc xlink:type="locator" xlink:href="aos-20171231.xsd#aos_ValuationAllowanceForTradeAndNotesReceivableMember" xlink:label="aos_ValuationAllowanceForTradeAndNotesReceivableMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation" xlink:label="aos_ValuationAllowanceForTradeAndNotesReceivableMember_lbl" xml:lang="en-US" id="id_9887657_1677496_3_1">Valuation Allowance For Trade And Notes Receivable [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="aos_ValuationAllowanceForTradeAndNotesReceivableMember_lbl" xml:lang="en-US" id="id_9887657_1677496_1_1">Valuation Allowance For Trade And Notes Receivable [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="aos_ValuationAllowanceForTradeAndNotesReceivableMember_lbl" xml:lang="en-US" id="id_9887657_1677496_2_1">Valuation Allowance For Trade And Notes Receivable</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="aos_ValuationAllowanceForTradeAndNotesReceivableMember" xlink:to="aos_ValuationAllowanceForTradeAndNotesReceivableMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:label="us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_lbl" xml:lang="en-US" id="id_9887657_1554030_1_1">Valuation Allowance of Deferred Tax Assets [Member]</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_lbl" xml:lang="en-US" id="id_9887657_1554030_2_1">Valuation Allowance For Deferred Tax Assets</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember" xlink:to="us-gaap_ValuationAllowanceOfDeferredTaxAssetsMember_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance_lbl" xml:lang="en-US" id="id_9887657_1562479_1_1">Valuation Allowances and Reserves, Balance</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance_lbl" xml:lang="en-US" id="id_9887657_1562479_4_1">Balance at End of Year</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesBalance_lbl" xml:lang="en-US" id="id_9887657_1562479_5_1">Balance at Beginning of Year</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesBalance" xlink:to="us-gaap_ValuationAllowancesAndReservesBalance_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl" xml:lang="en-US" id="id_9887657_1560721_1_1">Valuation Allowances and Reserves, Additions for Charges to Cost and Expense</label>
    <label xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel" xlink:label="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl" xml:lang="en-US" id="id_9887657_1560721_2_1">Charged to Costs and Expenses</label>
    <labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense" xlink:to="us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_lbl"/>
    <loc xlink:type="locator" xlink:href="http://xbrl.fasb.org/us-gaap/2017/elts/us-gaap-2017-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions" xlink:label="us-gaap_ValuationAllowancesAndReservesDeductions"/>
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