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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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 tarTnasVNb2Y1W16SKygMw==

<SEC-DOCUMENT>0001179110-04-019734.txt : 20041015
<SEC-HEADER>0001179110-04-019734.hdr.sgml : 20041015
<ACCEPTANCE-DATETIME>20041015093920
ACCESSION NUMBER:		0001179110-04-019734
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041014
FILED AS OF DATE:		20041015
DATE AS OF CHANGE:		20041015

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:			FLORNESS DANIEL L
		CENTRAL INDEX KEY:			0001017427

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16125
		FILM NUMBER:		041079970

	BUSINESS ADDRESS:	
		STREET 1:		FASTENAL CO
		STREET 2:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987
		BUSINESS PHONE:		5074545374

	MAIL ADDRESS:	
		STREET 1:		FASTENAL CO
		STREET 2:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-10-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000815556</issuerCik>
        <issuerName>FASTENAL CO</issuerName>
        <issuerTradingSymbol>FAST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001017427</rptOwnerCik>
            <rptOwnerName>FLORNESS DANIEL L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2001 THEURER BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WINONA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55987</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Exec. V-P and CFO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-10-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>52.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4016</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">An additional 361 shares of issuers common stock are indirectly owned through the issuers 401(k) plan as of September 30, 2004.  Participants in the plans issuer stock fund hold units which consist of undivided interests in the securities of the issuer and cash held in the fund.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John Milek, Attorney-in-Fact</signatureName>
        <signatureDate>2004-10-15</signatureDate>
    </ownerSignature>
</ownershipDocument>

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