-----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,
 Cn9cqvJ8gkfor+strVac0+HP2bn0dfxt61Jujengc+yabngpsckXCtbvLeEwGSeU
 vMFK+KbF26gqv5oKG5gPHA==

<SEC-DOCUMENT>0000073309-03-000029.txt : 20030902
<SEC-HEADER>0000073309-03-000029.hdr.sgml : 20030901
<ACCEPTANCE-DATETIME>20030902140500
ACCESSION NUMBER:		0000073309-03-000029
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030901
FILED AS OF DATE:		20030902

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NUCOR CORP
		CENTRAL INDEX KEY:			0000073309
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL WORKS, BLAST FURNACES  ROLLING MILLS (COKE OVENS) [3312]
		IRS NUMBER:				131860817
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2100 REXFORD RD
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28211
		BUSINESS PHONE:		7043667000

	MAIL ADDRESS:	
		STREET 1:		2100 REXFORD ROAD
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28211

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NUCLEAR CORP OF AMERICA INC
		DATE OF NAME CHANGE:	19680911

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AZTEC MECHANICAL CONTRACTORS INC
		DATE OF NAME CHANGE:	19660629

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RUTKOWSKI JOSEPH A
		CENTRAL INDEX KEY:			0001181107

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-04119
		FILM NUMBER:		03875906

	BUSINESS ADDRESS:	
		STREET 1:		2100 REXFORD RD
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28211
		BUSINESS PHONE:		7043667000

	MAIL ADDRESS:	
		STREET 1:		2100 REXFORD RD
		CITY:			CHARLOTTE
		STATE:			NC
		ZIP:			28211
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001181107d20030902f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-09-01</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000073309</issuerCik><issuerName>NUCOR CORP</issuerName>        <issuerTradingSymbol>NUE</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001181107</rptOwnerCik><rptOwnerName>RUTKOWSKI JOSEPH A</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>2100 REXFORD ROAD</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>CHARLOTTE</rptOwnerCity><rptOwnerState>NC</rptOwnerState><rptOwnerZipCode>28211-</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>EXECUTIVE VICE PRESIDENT</officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><nonDeri
vativeTable><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>20325</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeTransaction><securityTitle><value>Stock Option</value></securityTitle><conversionOrExercisePrice><value>51.29</value></conversionOrExercisePrice><transactionDate><value>2003-09-01</value></transactionDate><deemedExecutionDate><value>2003-09-01</value></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>4874</value></transactionShares><transactionPricePerShare><value>0</value></transac
tionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2003-09-01</value></exerciseDate><expirationDate><value>2010-08-31</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>4874</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>4874</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes></footnotes><ownerSignature><signatureName>Kelly J. Wilmoth - Attorney-in-fact</signatureName><signatureDate>2003-09-02</signatureDate></ownerSignature></ownershipDocument>

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