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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 P0m8m7Tm55/KHOqD2NXIn1ZhyWptVU8rnMBkACpd5vnt6JWChGFYu5W0bkW+UGdw
 8P4ZczGjSUbtPAtHYIOHcA==

<SEC-DOCUMENT>0000276889-04-000003.txt : 20040105
<SEC-HEADER>0000276889-04-000003.hdr.sgml : 20040105
<ACCEPTANCE-DATETIME>20040105141727
ACCESSION NUMBER:		0000276889-04-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031230
FILED AS OF DATE:		20040105

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			QUANEX CORP
		CENTRAL INDEX KEY:			0000276889
		STANDARD INDUSTRIAL CLASSIFICATION:	ROLLING DRAWING & EXTRUDING OF NONFERROUS METALS [3350]
		IRS NUMBER:				381872178
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1031

	BUSINESS ADDRESS:	
		STREET 1:		1900 W LOOP S STE 1500
		STREET 2:		ATTN WENDY RODENBECK
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77027
		BUSINESS PHONE:		713-877-5328

	MAIL ADDRESS:	
		STREET 1:		1900 WEST LOOP SOUTH
		STREET 2:		SUITE 1500
		CITY:			HOUSTON
		STATE:			TX
		ZIP:			77027

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MURPHY TERRY M
		CENTRAL INDEX KEY:			0001015235

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05725
		FILM NUMBER:		04503668

	BUSINESS ADDRESS:	
		STREET 1:		ONE MADISON AVENUE
		CITY:			CADILLAC
		STATE:			MI
		ZIP:			49601
		BUSINESS PHONE:		6167792200

	MAIL ADDRESS:	
		STREET 1:		ONE MADISON AVENUE
		CITY:			CADILLAC
		STATE:			MI
		ZIP:			49601
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001015235d20040105f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-12-30</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000276889</issuerCik><issuerName>QUANEX CORP</issuerName>        <issuerTradingSymbol>NX</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001015235</rptOwnerCik><rptOwnerName>MURPHY TERRY M</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>1900 WEST LOOP SOUTH</rptOwnerStreet1><rptOwnerStreet2>SUITE 1500</rptOwnerStreet2><rptOwnerCity>HOUSTON</rptOwnerCity><rptOwnerState>TX</rptOwnerState><rptOwnerZipCode>77027</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Vice President &amp; CFO</officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><n
onDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-12-30</value></transactionDate><deemedExecutionDate><value>2003-12-31</value></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1"/></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>3.521</value></transactionShares><transactionPricePerShare><value>47.3998</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>7396.163</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershi
pNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-02</value></transactionDate><deemedExecutionDate><value>2004-01-05</value></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F2"/></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>9.795</value></transactionShares><transactionPricePerShare><value>46.9639</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>7405.958</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwn
ership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><derivativeTable></derivativeTable><footnotes><footnote id="F1">Acquired through Quanex Dividend Reinvestment Plan.</footnote><footnote id="F2">Shares acquired through Employee Stock Purchase Plan.</footnote></footnotes><ownerSignature><signatureName>Terry M Murphy</signatureName><signatureDate>2004-01-05</signatureDate></ownerSignature></ownershipDocument>

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</SEC-DOCUMENT>
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