<SEC-DOCUMENT>0001628280-16-018838.txt : 20160809
<SEC-HEADER>0001628280-16-018838.hdr.sgml : 20160809
<ACCEPTANCE-DATETIME>20160809191422
ACCESSION NUMBER:		0001628280-16-018838
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160806
FILED AS OF DATE:		20160809
DATE AS OF CHANGE:		20160809

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KLA TENCOR CORP
		CENTRAL INDEX KEY:			0000319201
		STANDARD INDUSTRIAL CLASSIFICATION:	OPTICAL INSTRUMENTS & LENSES [3827]
		IRS NUMBER:				042564110
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		ONE TECHNOLOGY DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035
		BUSINESS PHONE:		4088756000

	MAIL ADDRESS:	
		STREET 1:		ONE TECHNOLOGY DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KLA INSTRUMENTS CORP
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kirk Michael
		CENTRAL INDEX KEY:			0001582625

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-09992
		FILM NUMBER:		161819647

	MAIL ADDRESS:	
		STREET 1:		ONE TECHNOLOGY DRIVE
		CITY:			MILPITAS
		STATE:			CA
		ZIP:			95035
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_147078444921944.xml
<DESCRIPTION>FORM 4
<TEXT>
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        <issuerName>KLA TENCOR CORP</issuerName>
        <issuerTradingSymbol>KLAC</issuerTradingSymbol>
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            <rptOwnerStreet1>C/O KLA-TENCOR CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE TECHNOLOGY DRIVE</rptOwnerStreet2>
            <rptOwnerCity>MILPITAS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95035</rptOwnerZipCode>
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            <isDirector>0</isDirector>
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            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President</officerTitle>
            <otherText></otherText>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2016-08-07</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
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                    <value>A</value>
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                    <value>D</value>
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                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock - Restricted Stock Units</value>
                <footnoteId id="F7"/>
            </securityTitle>
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                <sharesOwnedFollowingTransaction>
                    <value>57748</value>
                    <footnoteId id="F8"/>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
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    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On August 6, 2013, the Reporting Person received a grant of restricted stock units (&quot;RSUs&quot;) covering 13,350 shares of KLA-Tencor common stock.  On August 6, 2016, the Reporting Person vested in twenty-five percent (25%) of such RSUs.</footnote>
        <footnote id="F2">Pursuant to such terms of the August 6, 2013 RSU grant, 1,742 shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding.  Because the vesting date of such RSUs occurred on a day on which the NASDAQ Stock Market was closed for trading, the fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on the last completed trading day immediately prior to such vesting date.</footnote>
        <footnote id="F3">On August 6, 2015, the Reporting Person received a grant of RSUs covering 17,650 shares of KLA-Tencor common stock.  On August 6, 2016, the Reporting Person vested in twenty-five percent (25%) of such RSUs.</footnote>
        <footnote id="F4">Pursuant to such terms of the August 6, 2015 RSU grant, 2,303 shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding.  Because the vesting date of such RSUs occurred on a day on which the NASDAQ Stock Market was closed for trading, the fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on the last completed trading day immediately prior to such vesting date.</footnote>
        <footnote id="F5">On August 7, 2014, the Reporting Person received a grant of RSUs covering 14,650 shares of KLA-Tencor common stock.  On August 7, 2016, the Reporting Person vested in twenty-five percent (25%) of such RSUs.</footnote>
        <footnote id="F6">Pursuant to such terms of the August 7, 2014 RSU grant, 1,912 shares of KLA-Tencor common stock were automatically withheld at vesting to cover required tax withholding.  Because the vesting date of such RSUs occurred on a day on which the NASDAQ Stock Market was closed for trading, the fair market value of KLA-Tencor common stock used for purposes of calculating the number of shares to be withheld was the closing price of KLA-Tencor common stock as reported on the last completed trading day immediately prior to such vesting date.</footnote>
        <footnote id="F7">Each RSU represents a contingent right to receive one share of KLA-Tencor common stock.</footnote>
        <footnote id="F8">Does not include performance-based RSUs, if any, held by the Reporting Person for which an assessment has not yet been made regarding the achievement of the applicable performance goals.  Any such holdings will be reported on a Form 4 within two business days of the date such assessment is made.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Teri A. Little as Attorney-in-Fact for Michael Kirk</signatureName>
        <signatureDate>2016-08-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</DOCUMENT>
</SEC-DOCUMENT>
