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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 ULqI59QlMm6SZsOYz2kLmaSKQ9p9uaKv/5wRXvgk/E6kCX+pySGjlRlU1W7VSyuo
 461kXq4nuLJ/Hi376GHnxw==

<SEC-DOCUMENT>0000276889-04-000005.txt : 20040105
<SEC-HEADER>0000276889-04-000005.hdr.sgml : 20040105
<ACCEPTANCE-DATETIME>20040105141805
ACCESSION NUMBER:		0000276889-04-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031230
FILED AS OF DATE:		20040105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BALLOU ROBERT C
		CENTRAL INDEX KEY:			0001232999

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05725
		FILM NUMBER:		04503677

	BUSINESS ADDRESS:	
		STREET 1:		4971 BIRDIE LANE
		CITY:			ANN ARBOR
		STATE:			MI
		ZIP:			48103

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001232999d20040105f4f.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>0001232999</rptOwnerCik><rptOwnerName>BALLOU ROBERT C</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>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>1</isOther><officerTitle></officerTitle><otherText>President - Vehicular Products</otherText></reportingOwnerRelationship></reportingO
wner><nonDerivativeTable><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>1.507</value></transactionShares><transactionPricePerShare><value>47.3998</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2921.826</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></o
wnershipNature></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>19.59</value></transactionShares><transactionPricePerShare><value>46.9639</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2941.416</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natu
reOfOwnership></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, Power of Attorney</signatureName><signatureDate>2004-01-05</signatureDate></ownerSignature></ownershipDocument>

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</SEC-DOCUMENT>
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