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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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 jZrdH5XLEsKEA9AJhewuSw==

<SEC-DOCUMENT>0001209191-07-051875.txt : 20070905
<SEC-HEADER>0001209191-07-051875.hdr.sgml : 20070905
<ACCEPTANCE-DATETIME>20070905095039
ACCESSION NUMBER:		0001209191-07-051875
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070905
FILED AS OF DATE:		20070905
DATE AS OF CHANGE:		20070905

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KOMAG INC /DE/
		CENTRAL INDEX KEY:			0000813347
		STANDARD INDUSTRIAL CLASSIFICATION:	MAGNETIC & OPTICAL RECORDING MEDIA [3695]
		IRS NUMBER:				942914864
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0102

	BUSINESS ADDRESS:	
		STREET 1:		1710 AUTOMATION PWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
		BUSINESS PHONE:		4085762000

	MAIL ADDRESS:	
		STREET 1:		1710 AUTOMATION PWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			YAMASHITA TSUTOMU T
		CENTRAL INDEX KEY:			0001230580

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16852
		FILM NUMBER:		071098395

	BUSINESS ADDRESS:	
		STREET 1:		KOMAG INCORPORATED
		STREET 2:		1710 AUTOMATION PARKWAY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131
		BUSINESS PHONE:		4085762000
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-09-05</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000813347</issuerCik>
        <issuerName>KOMAG INC /DE/</issuerName>
        <issuerTradingSymbol>KOMG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001230580</rptOwnerCik>
            <rptOwnerName>YAMASHITA TSUTOMU T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1710 AUTOMATION PARKWAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP, CTO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-09-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>43117</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock option (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>18.85</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-09-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1693</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.40</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-03-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1693</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock option (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>32.10</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2007-09-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>14717</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.15</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2017-02-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>14717</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Of these shares, 3,333 were issued pursuant to a 10,000 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of February 15, 2006, February 15, 2007 and February 15, 2008. Of these shares, 9,333 were issued pursuant to a 14,000 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of February 15, 2007, February 15, 2008 and February 15, 2009. Of these shares, 25,000 were issued pursuant to a 25,000 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of October 3, 2007, October 3, 2008 and October 3, 2009. Of these shares, 5,451 were issued pursuant to a 5,451 share restricted stock agreement, which provided for vesting at the rate of 1/3rd of the shares on each of February 15, 2008, February 15, 2009 and February 15, 2010.</footnote>
        <footnote id="F2">Continuation of footnote (1). All 43,117 of such shares were canceled in the merger of State M Corporation, a wholly-owned subsidiary of Western Digital Corporation (the &quot;Parent&quot;), with and into the Issuer (the &quot;Merger&quot;), in exchange for a right to receive cash in the aggregate amount of $1,390,523.25 (or $32.25 per share); provided, however, that the receipt of cash will remain subject to the vesting provisions set forth in the restricted stock agreements and Parent is only obligated to pay cash to the extent the right vests during continued employment.</footnote>
        <footnote id="F3">This option, originally for 6,250 shares and which provided for vesting at the rate of 1/4th of the shares on 03/15/05 and as to 1/36th of the remaining shares on the 15th of each month thereafter, was canceled in the Merger in exchange for a right to receive cash in the aggregate amount of $22,686.20, less any applicable withholding taxes, representing the difference between the exercise price of the option and the $32.25 per share offer price (the &quot;Offer Price&quot;) in the Merger; provided, however, that the receipt of cash will remain subject to the vesting provisions set forth in the option and Parent is only obligated to pay cash to the extent the right vests during continued employment.</footnote>
        <footnote id="F4">This option, which provided for vesting at the rate of 4,906 shares on 02/15/08 and as to 1/24th of the remaining shares on the 15th of each month thereafter, was canceled in the Merger in exchange for a right to receive cash in the aggregate amount of $2,207.55, less any applicable withholding taxes, representing the difference between the exercise price of the option and the Offer Price; provided, however, that the receipt of cash will remain subject to the vesting provisions set forth in the option and Parent is only obligated to pay cash to the extent the right vests during continued employment.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jan Schwartz, Attorney-in-fact for Tsutomu Yamashita</signatureName>
        <signatureDate>2007-09-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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