<SEC-DOCUMENT>0001140361-15-041970.txt : 20151117
<SEC-HEADER>0001140361-15-041970.hdr.sgml : 20151117
<ACCEPTANCE-DATETIME>20151117113125
ACCESSION NUMBER:		0001140361-15-041970
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20151116
FILED AS OF DATE:		20151117
DATE AS OF CHANGE:		20151117

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:			FREEMAN MICHAEL L
		CENTRAL INDEX KEY:			0001191593

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06936
		FILM NUMBER:		151237456

	MAIL ADDRESS:	
		STREET 1:		405 SANDALWOOD COURT
		CITY:			ENCINITAS
		STATE:			CA
		ZIP:			92024
</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>2015-11-16</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001191593</rptOwnerCik>
            <rptOwnerName>FREEMAN MICHAEL L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1061 CUDAHY PLACE</rptOwnerStreet1>
            <rptOwnerStreet2></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>Division President, Americas</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-11-16</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3709</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>94.86</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27286.404</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Transaction pursuant to trading plan adopted pursuant to Rule 10b5-1 under Securities Exchange Act of 1934.</footnote>
        <footnote id="F2">Average price for multiple sales at prices ranging from $95.13 to $94.60 per share.</footnote>
        <footnote id="F3">Total includes 2312.404 shares held in WD-40 Company Profit Sharing Plan (Company Stock Fund) account.  Also includes 5980 Restricted Stock Units, of which 2009 are subject to future vesting, and 3150 Market Share Units, all of which are subject to future vesting.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Richard T. Clampitt, attorney-in-fact for Michael L Freeman</signatureName>
        <signatureDate>2015-11-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
