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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 DGEKyG/4AG33OEnPDA66lA==

<SEC-DOCUMENT>0001179110-03-007495.txt : 20030917
<SEC-HEADER>0001179110-03-007495.hdr.sgml : 20030917
<ACCEPTANCE-DATETIME>20030917112443
ACCESSION NUMBER:		0001179110-03-007495
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030917
FILED AS OF DATE:		20030917

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FASTENAL CO
		CENTRAL INDEX KEY:			0000815556
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-BUILDING MATERIALS, HARDWARE, GARDEN SUPPLY [5200]
		IRS NUMBER:				410948415
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987
		BUSINESS PHONE:		5074545374

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			OBERTON WILLARD D
		CENTRAL INDEX KEY:			0001036295

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16125
		FILM NUMBER:		03898873

	BUSINESS ADDRESS:	
		STREET 1:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987
		BUSINESS PHONE:		5074545374

	MAIL ADDRESS:	
		STREET 1:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-09-17</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000815556</issuerCik>
        <issuerName>FASTENAL CO</issuerName>
        <issuerTradingSymbol>FAST</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001036295</rptOwnerCik>
            <rptOwnerName>OBERTON WILLARD D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2001 THEURER BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WINONA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55987</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>CEO and President</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-09-17</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>2000</value>
</transactionShares>
<transactionPricePerShare><value>27.50</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>119520</value>
<footnoteId id="F1"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-09-17</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>D</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>2000</value>
</transactionShares>
<transactionPricePerShare><value>42.46</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>117520</value>
<footnoteId id="F1"></footnoteId>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable><derivativeTransaction><securityTitle><value>Stock Appreciation Right</value>
</securityTitle>
<conversionOrExercisePrice><value>27.50</value>
</conversionOrExercisePrice>
<transactionDate><value>2003-09-17</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>M</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>2000</value>
</transactionShares>
<transactionPricePerShare><value>0</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<exerciseDate><value>2003-07-01</value>
</exerciseDate>
<expirationDate><value>2003-12-31</value>
</expirationDate>
<underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value>
</underlyingSecurityTitle>
<underlyingSecurityShares><value>2000</value>
</underlyingSecurityShares>
</underlyingSecurity>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>0</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</derivativeTransaction>
</derivativeTable>
<footnotes><footnote id="F1">An additional 35,800 shares of issuer's common stock are owned by the reporting person's spouse.  And additional 7,800 shares of issuer's common stock are held by the reporting person and the reporting person's spouse as Custodians for their minor children.  The reporting person disclaims beneficial ownership of all of the shares listed in this footnote.</footnote>
</footnotes>
<ownerSignature><signatureName>John Milek, Attorney-in-Fact</signatureName>
<signatureDate>2003-09-17</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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