<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-12-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000945489</issuerCik>
        <issuerName>BELL INDUSTRIES INC /NEW/</issuerName>
        <issuerTradingSymbol>BI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000932334</rptOwnerCik>
            <rptOwnerName>NEWCASTLE PARTNERS L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 CRESCENT COURT</rptOwnerStreet1>
            <rptOwnerStreet2>STE 1400</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001251296</rptOwnerCik>
            <rptOwnerName>NEWCASTLE CAPITAL MANAGEMENT LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 CRESCENT COURT</rptOwnerStreet1>
            <rptOwnerStreet2>STE 1400</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001251293</rptOwnerCik>
            <rptOwnerName>NEWCASTLE CAPITAL GROUP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 CRESCENT COURT</rptOwnerStreet1>
            <rptOwnerStreet2>STE 1400</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001208889</rptOwnerCik>
            <rptOwnerName>SCHWARZ MARK E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 CRESCENT COURT</rptOwnerStreet1>
            <rptOwnerStreet2>STE 1400</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</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, $.001 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2006-12-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.3</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>562500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $.001 par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2007-01-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.6</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>565100</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Owned directly by Newcastle Partners, L.P. (&quot;NP&quot;).  Newcastle Capital Management, L.P. (&quot;NCM&quot;) is the general partner of NP, Newcastle Capital Group, L.L.C. (&quot;NCG&quot;) is the general partner of NCM and Mark E. Schwarz (&quot;Schwarz&quot;) is the managing member of NCG.  Accordingly, each of NCM, NCG and Schwarz may be deemed to beneficially own the shares described herein.  The reporting persons are members of a Section 13(d) group.  NP disclaims beneficial ownership of any shares owned by any other member of the group.  Schwarz, NCM and NCG disclaim beneficial ownership of the shares owned by NP, except to the extent of their pecuniary interest therein, and any other shares owned by any other member of the group.  Mark Schwarz is a director of Bell Industries, Inc.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Newcastle Partners, L.P., By: Newcastle Capital Management, L.P., its general partner, By: Newcastle Capital Group, L.L.C. its general partner, by:/s/ Mark E. Schwarz, its managing member</signatureName>
        <signatureDate>2007-01-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Newcastle Capital Management, L.P., By: Newcastle Capital Group, L.L.C. its general partner, By: /s/ Mark E. Schwarz, its managing member</signatureName>
        <signatureDate>2007-01-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Newcastle Capital Group, L.L.C., By: /s/ Mark E. Schwarz, its managing member</signatureName>
        <signatureDate>2007-01-22</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Mark E. Schwarz</signatureName>
        <signatureDate>2007-01-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
