<SEC-DOCUMENT>0001123292-18-000591.txt : 20180329
<SEC-HEADER>0001123292-18-000591.hdr.sgml : 20180329
<ACCEPTANCE-DATETIME>20180329172747
ACCESSION NUMBER:		0001123292-18-000591
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180327
FILED AS OF DATE:		20180329
DATE AS OF CHANGE:		20180329

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MOLLINS GREGG J
		CENTRAL INDEX KEY:			0001256539

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13122
		FILM NUMBER:		18724083

	MAIL ADDRESS:	
		STREET 1:		350 S GRAND AVE STE 5100
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RELIANCE STEEL & ALUMINUM CO
		CENTRAL INDEX KEY:			0000861884
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-METALS SERVICE CENTERS & OFFICES [5051]
		IRS NUMBER:				951142616
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		350 S GRAND AVE STE 5100
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071
		BUSINESS PHONE:		213-687-7700

	MAIL ADDRESS:	
		STREET 1:		350 S GRAND AVE STE 5100
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90071
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-03-27</periodOfReport>

    <issuer>
        <issuerCik>0000861884</issuerCik>
        <issuerName>RELIANCE STEEL &amp; ALUMINUM CO</issuerName>
        <issuerTradingSymbol>RS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001256539</rptOwnerCik>
            <rptOwnerName>MOLLINS GREGG J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>350 SOUTH GRAND AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 5100</rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90071</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-03-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>17110</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>219005</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12775</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held by Trustee of Reliance Steel &amp; Aluminum Co. Employee Stock Ownership Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Gregg J. Mollins by William A. Smith II as his Attorney-in-Fact</signatureName>
        <signatureDate>2018-03-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
