<SEC-DOCUMENT>0001140361-15-038710.txt : 20151027
<SEC-HEADER>0001140361-15-038710.hdr.sgml : 20151027
<ACCEPTANCE-DATETIME>20151027190103
ACCESSION NUMBER:		0001140361-15-038710
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20151023
FILED AS OF DATE:		20151027
DATE AS OF CHANGE:		20151027

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SEWITCH STANLEY JR
		CENTRAL INDEX KEY:			0001619180

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06936
		FILM NUMBER:		151178790

	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>2015-10-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001619180</rptOwnerCik>
            <rptOwnerName>SEWITCH STANLEY JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>WD-40 COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>1061 CUDAHY PLACE</rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP, Global Org. Dev.</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-10-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>316</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7870.073</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-10-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>551</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7319.073</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares withheld pursuant to mandatory provisions of Restricted Stock Unit (RSU) Award Agreements in satisfaction of tax withholding obligation upon settlement of 837 RSUs (Common Stock equivalents).</footnote>
        <footnote id="F2">Shares withheld pursuant to mandatory provisions of Market Stock Unit (MSU) Award Agreements in satisfaction of tax withholding obligation upon settlement of 1,466 MSUs (Common Stock equivalents).</footnote>
        <footnote id="F3">Total includes 975.073 shares held in WD-40 Company Profit Sharing Plan (Company Stock Fund) account. Total also includes 1,547 Restricted Stock Units, all of which are subject to future vesting and 2,307 Market Share Units, all of which are subject to future vesting.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Richard T. Clampitt, as attorney-in-fact for Stanley Sewitch, Jr.</signatureName>
        <signatureDate>2015-10-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
