-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 OhC60NUuAkp4Afad58NxEnxWmGC/qRhv49rHIPvhtH9aKp+tEZJ9KnHueWuucc3z
 NxuiJltvoDLZsgv8dFqg0g==

<SEC-DOCUMENT>0001209191-04-043886.txt : 20040909
<SEC-HEADER>0001209191-04-043886.hdr.sgml : 20040909
<ACCEPTANCE-DATETIME>20040909170408
ACCESSION NUMBER:		0001209191-04-043886
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040909
FILED AS OF DATE:		20040909
DATE AS OF CHANGE:		20040909

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KASHNOW RICHARD A
		CENTRAL INDEX KEY:			0001135025

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16852
		FILM NUMBER:		041023537

	BUSINESS ADDRESS:	
		STREET 1:		313 CONSTITUTION DR
		STREET 2:		STE 100
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025

	MAIL ADDRESS:	
		STREET 1:		313 CONSTITUTION DR
		STREET 2:		STE 100
		CITY:			MENLO PARK
		STATE:			CA
		ZIP:			94025

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
</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>2004-09-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001135025</rptOwnerCik>
            <rptOwnerName>KASHNOW RICHARD A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>313 CONSTITUTION DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>MENLO PARK</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94025</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-09-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.01</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Purchase Right (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.01</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-09-09</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-08-19</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2004-09-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">3,334 shares subject to the stock purchase right shall be released from the Company's Repurchase Option on August 19, 2005, 3,333 shares subject to the stock purchase right shall be released from the Company's Repurchase Option on August 19, 2006, 3,333 shares subject to the stock purchase right shall be released from the Company's Repurchase Option on August 19, 2007, provided that the Reporter does not cease to be a Participant of the Komag Incorporated Amended and Restated 2002 Qualifed Stock Plan on such dates.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jan Schwartz, Attorney-in-fact for Richard A. Kashnow</signatureName>
        <signatureDate>2004-09-09</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----