<SEC-DOCUMENT>0001140361-17-038477.txt : 20171011
<SEC-HEADER>0001140361-17-038477.hdr.sgml : 20171011
<ACCEPTANCE-DATETIME>20171011194326
ACCESSION NUMBER:		0001140361-17-038477
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20171009
FILED AS OF DATE:		20171011
DATE AS OF CHANGE:		20171011

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			NOBLE WILLIAM B
		CENTRAL INDEX KEY:			0001253564

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06936
		FILM NUMBER:		171133587

	MAIL ADDRESS:	
		STREET 1:		BRICK CLOSE, KIIN FARM
		CITY:			MILTON KEYNES
		STATE:			X0
		ZIP:			MK1 13LJ

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WD 40 CO
		CENTRAL INDEX KEY:			0000105132
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS CHEMICAL PRODUCTS [2890]
		IRS NUMBER:				951797918
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		1061 CUDAHY PL
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110
		BUSINESS PHONE:		6192751400

	MAIL ADDRESS:	
		STREET 1:		1061 CUDAHY PLACE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-10-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000105132</issuerCik>
        <issuerName>WD 40 CO</issuerName>
        <issuerTradingSymbol>WDFC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001253564</rptOwnerCik>
            <rptOwnerName>NOBLE WILLIAM B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BRICK CLOSE</rptOwnerStreet1>
            <rptOwnerStreet2>KIIN FARM</rptOwnerStreet2>
            <rptOwnerCity>MILTON KEYNES</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>MK1 13LJ</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Managing Director, Europe</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-10-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>509</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12326</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-10-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>806</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13132</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock Units (Common Stock equivalents) were granted pursuant to the WD-40 Company 2016 Stock Incentive Plan. The Restricted Stock Units (RSUs) will be settled solely with Issuer Common Stock upon an annual vesting schedule as provided for in the Award Agreement for the RSUs as follows: 34% not later than November 15, 2018, 33% not later than November 15, 2019, and 33% not later than November 15, 2020.</footnote>
        <footnote id="F2">Acquisition of additional vested Market Share Units (Common Stock equivalents) upon certified performance vesting of Market Share Units (MSUs) awarded to the reporting person on October 13, 2014. Vested MSUs will be settled solely with Issuer Common Stock not later than November 15, 2017.</footnote>
        <footnote id="F3">Total includes 5,613 RSUs, of which 1,642 are subject to future vesting, 571 MSUs (target number) awarded to the reporting person in 2015, all of which are subject to future vesting, 1,612 vested MSUs, and 280 vested Deferred Performance Units (Common Stock equivalents). MSUs (which are performance-based equity awards) that were granted to the reporting person on October 11, 2016 and October 9, 2017 are not reported herein as beneficially owned Common Stock equivalents.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Richard T. Clampitt, as attorney-in-fact for William B. Noble</signatureName>
        <signatureDate>2017-10-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
