<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-01-14</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000055604</issuerCik>
        <issuerName>KEYSTONE CONSOLIDATED INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>kesn</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000024240</rptOwnerCik>
            <rptOwnerName>CONTRAN CORP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeSecurity>
        <securityTitle>
            <value>Series A Convertible Preferred Stock</value>
            <footnoteId id="F1"/>
        </securityTitle>
        <conversionOrExercisePrice>
            <value>4</value>
            <footnoteId id="F2"/>
        </conversionOrExercisePrice>
        <transactionDate>
            <value>2003-01-14</value>
            <footnoteId id="F3"/>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>P</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>54956</value>
            </transactionShares>
            <transactionValue>
                <value>211.08</value>
                <footnoteId id="F6"/>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>A</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <exerciseDate>
            <value>2003-03-15</value>
            <footnoteId id="F4"/>
        </exerciseDate>
        <expirationDate>
            <value>1998-08-08</value>
            <footnoteId id="F5"/>
        </expirationDate>
        <underlyingSecurity>
            <underlyingSecurityTitle>
                <value>Common Stock $1.00 par value</value>
            </underlyingSecurityTitle>
            <underlyingSecurityShares>
                <value>13739000</value>
                <footnoteId id="F4"/>
            </underlyingSecurityShares>
        </underlyingSecurity>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>54956</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
                <footnoteId id="F7"/>
            </directOrIndirectOwnership>
        </ownershipNature>
    </derivativeSecurity>

    <footnotes>
        <footnote id="F1">The issuer's Series A 10% Cumulative Convertible Pay-In-Kind Preferred Stock, stated value $1,000 and no par value per share (the &quot;Series A Preferred Stock&quot;), the terms of which are set forth in, and incorporated herein by reference from, the Amended and Restated Certificate of Designations, Rights and Preferences of the Series A 10% Cumulative Convertible Pay-In-Kind Preferred Stock filed as Exhibit 3.2 to the issuer's Annual Report on Form 10-K for the fiscal year ended December 31, 2002 with the Securities and Exchange Commission (the &quot;Amended and Restated Certificate of Designations&quot;).</footnote>
        <footnote id="F2">The conversion price is based on the current conversion price of $4.00 per share Series A Preferred Stock, which is equivalent to one share of Series A Preferred Stock convertible into 250 shares of the issuer's common stock.  The conversion price may be adjusted from time to time pursuant to the Amended and Restated Certificate of Designations.</footnote>
        <footnote id="F3">Contran purchased 54,956 shares of Series A Preferred Stock on October 16, 2003.  Shares of Series A Preferred Stock do not become convertible into shares of the issuer's common stock until March 15, 2003.  The reporting person is deemed to own the underlying common stock 60 days prior to the March 15, 2003 conversion date, or January 14, 2003.</footnote>
        <footnote id="F4">There is currently a limitation on the full conversion of these shares of Series A Preferred Stock into shares of the issuer's common stock due to the current authorized number of shares of the issuer's common stock set forth in the issuer's Restated Certificate of Incorporation.  See the additional information attached as an exhibit to this statement for a description of this limitation.</footnote>
        <footnote id="F5">There is no expiration date.</footnote>
        <footnote id="F6">The aggregate purchase price for the 54,956 shares of Series A Preferred Stock was $11,600,000.00.</footnote>
        <footnote id="F7">See the additional information attached as an exhibit to this statement for a description of additional shares of the issuer's common stock the reporting person may be deemed to beneficially own, directly or indirectly.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Contran Corporation by A. Andrew R. Louis, Secretary</signatureName>
        <signatureDate>2003-06-30</signatureDate>
    </ownerSignature>

</ownershipDocument>

