-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001182013-05-000001.txt : 20050523
<SEC-HEADER>0001182013-05-000001.hdr.sgml : 20050523
<ACCEPTANCE-DATETIME>20050523131234
ACCESSION NUMBER:		0001182013-05-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050428
FILED AS OF DATE:		20050523
DATE AS OF CHANGE:		20050523

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SYNALLOY CORP
		CENTRAL INDEX KEY:			0000095953
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL PIPE & TUBES [3317]
		IRS NUMBER:				570426694
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1230

	BUSINESS ADDRESS:	
		STREET 1:		CROFT INDUSTRIAL PARK
		STREET 2:		P O BOX 5627
		CITY:			SPARTANBURG
		STATE:			SC
		ZIP:			29304
		BUSINESS PHONE:		864-585-3605

	MAIL ADDRESS:	
		STREET 1:		P O BOX 5627
		CITY:			SPARTANBURG
		STATE:			SC
		ZIP:			29304

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BLACKMAN UHLER INDUSTRIES INC
		DATE OF NAME CHANGE:	19710510

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			FISHBURN SIBYL N
		CENTRAL INDEX KEY:			0001182013

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-19687
		FILM NUMBER:		05850501

	BUSINESS ADDRESS:	
		STREET 1:		3542 PEAKWOOD DR SW
		CITY:			ROANOKE
		STATE:			VA
		ZIP:			24014
		BUSINESS PHONE:		5403442262
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-04-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000095953</issuerCik>
        <issuerName>SYNALLOY CORP</issuerName>
        <issuerTradingSymbol>synl</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001182013</rptOwnerCik>
            <rptOwnerName>FISHBURN SIBYL N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></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>2005-04-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2195</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.39</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>63975</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7065</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Spouse</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">I expressly disclaim beneficial ownership of these securities and filing this report shall not be construed as an admission of my beneficial ownership thereof for purposes of Section 16 of the Securities Act, or otherwise.</footnote>
        <footnote id="F2">N/A</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Cheryl C. Carter, Power of Attorney for Sibyl N. Fishburn</signatureName>
        <signatureDate>2005-05-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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