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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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<SEC-DOCUMENT>0001005477-04-001775.txt : 20040504
<SEC-HEADER>0001005477-04-001775.hdr.sgml : 20040504
<ACCEPTANCE-DATETIME>20040504164953
ACCESSION NUMBER:		0001005477-04-001775
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040129
FILED AS OF DATE:		20040504

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:			FEINBERG STEPHEN
		CENTRAL INDEX KEY:			0000947822
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16852
		FILM NUMBER:		04778298

	BUSINESS ADDRESS:	
		STREET 1:		450 PARK AVE
		STREET 2:		28TH FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		2128912120

	MAIL ADDRESS:	
		STREET 1:		450 PARK AVE
		STREET 2:		28TH FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar123.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-01-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000947822</rptOwnerCik>
            <rptOwnerName>FEINBERG STEPHEN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CERBERUS CAPITAL MANAGEMENT, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>299 PARK AVENUE - 22ND FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10171</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2004-01-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>500000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6426800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By partnerships, corporations and companies</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Cerberus Partners, L.P., a Delaware limited partnership (&quot;Cerberus&quot;), is the holder of 683,147 shares of the common stock (the &quot;Shares&quot;) of Komag, Incorporated (the &quot;Company&quot;), Cerberus International, Ltd., a corporation organized under the laws of the Bahamas (&quot;International&quot;), is the holder of 3,086,762 Shares, Cerberus Series One Holdings, LLC, a Delaware limited liability company (&quot;Cerberus Series One&quot;), is the holder of 1,560,446 Shares, Cerberus Series Two Holdings, LLC, a Delaware limited liability company (&quot;Cerberus Series Two&quot;), is the holder of 929,208 Shares, and Cerberus America Series One Holdings, LLC, a Delaware limited liability company (&quot;Cerberus America&quot;, and together with Cerberus, International, Cerberus Series One and Cerberus Series Two, the &quot;Cerberus Entities&quot;), is the holder of 167,237 Shares.  On January 29, 2004, the Cerberus Entities sold an aggregate of 500,000 Shares pursuant
 to an underwritten offering.</footnote>
        <footnote id="F2">Stephen Feinberg possesses sole power to vote and direct the disposition of all securities of the Company owned by the Cerberus Entities.  Thus, for the purposes of Reg. Section 240.13d-3, Stephen Feinberg is deemed to beneficially own 6,426,800 Shares.  Stephen Feinberg's interest in the securities reported herein is limited to the extent of his pecuniary interest in each of the Cerberus Entities, if any.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Stephen Feinberg</signatureName>
        <signatureDate>2004-05-03</signatureDate>
    </ownerSignature>
</ownershipDocument>

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