<SEC-DOCUMENT>0001124194-16-000012.txt : 20160510
<SEC-HEADER>0001124194-16-000012.hdr.sgml : 20160510
<ACCEPTANCE-DATETIME>20160510142652
ACCESSION NUMBER:		0001124194-16-000012
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160506
FILED AS OF DATE:		20160510
DATE AS OF CHANGE:		20160510

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ILLINOIS TOOL WORKS INC
		CENTRAL INDEX KEY:			0000049826
		STANDARD INDUSTRIAL CLASSIFICATION:	GENERAL INDUSTRIAL MACHINERY & EQUIPMENT [3560]
		IRS NUMBER:				361258310
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		155 HARLEM AVENUE
		CITY:			GLENVIEW
		STATE:			IL
		ZIP:			60025
		BUSINESS PHONE:		8477247500

	MAIL ADDRESS:	
		STREET 1:		155 HARLEM AVENUE
		CITY:			GLENVIEW
		STATE:			IL
		ZIP:			60025

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CROWN SUSAN
		CENTRAL INDEX KEY:			0001124194

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-04797
		FILM NUMBER:		161635137

	MAIL ADDRESS:	
		STREET 1:		222 NORTH LASALLE STREET
		STREET 2:		SUITE 2000
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60601
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-05-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000049826</issuerCik>
        <issuerName>ILLINOIS TOOL WORKS INC</issuerName>
        <issuerTradingSymbol>ITW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001124194</rptOwnerCik>
            <rptOwnerName>CROWN SUSAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>222 NORTH LASALLE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 2000</rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60601</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-05-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1378</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>104.19</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46077</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See ftn.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See ftn.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5770</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5770</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 9,312 shares of deferred stock under the ITW Director's Deferred Fee Plan as of May 6, 2016.</footnote>
        <footnote id="F2">Owned by Reporting Person's spouse.</footnote>
        <footnote id="F3">Owned by a trust of which Reporting Person's children are beneficiaries.</footnote>
        <footnote id="F4">Represents units of phantom stock held by the Reporting Person as of May 6, 2016 under the Phantom Stock Plan for non-officer directors.  Each unit is equal in value to one share of common stock.  The units are not transferrable and have no voting rights.  Additional units are credited in amounts equivalent to cash dividends paid on the common stock reported as of May 6, 2016.</footnote>
    </footnotes>

    <remarks>The Reporting Person disclaims beneficial ownership of the shares described in Footnotes 2 and 3 except to the extent of her pecuniary interest therein.</remarks>

    <ownerSignature>
        <signatureName>/s/ Susan Crown</signatureName>
        <signatureDate>2016-05-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
