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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-09-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001287151</issuerCik>
        <issuerName>XERIUM TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>XRM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001291381</rptOwnerCik>
            <rptOwnerName>Wilson James Forbes</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CARL MARKS MANAGEMENT COMPANY, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>900 THIRD AVENUE, 33RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022-4775</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2010-09-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>113874</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1495830</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnotes 1&amp;2</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person is a director of Xerium Technologies, Inc. (the &quot;Issuer&quot;) and is one of three individual managing members of Carl Marks Management Company, LLC (&quot;CMMC&quot;), a Delaware limited liability company and registered investment adviser, which is the investment adviser to (i) Carl Marks Strategic Investments, L.P. (&quot;CMSI&quot;), a Delaware limited partnership and private investment partnership, and (ii) Carl Marks Strategic Opportunities Fund, L.P. (&quot;CMSO&quot;), a Delaware limited partnership and private investment partnership.  The reporting person is also one of three individual managing members of (i) CMSI GP, LLC (&quot;CMSI GP&quot;), a Delaware limited liability company and the general partner of CMSI, and (ii) Carl Marks GP, LLC (&quot;CMSO GP&quot;), a Delaware limited liability company and the general partner of CMSO.  On September 3, 2010, CMSI purchased 34,386 shares of Common Stock of the Issuer (&quot;Common Stock&quot;).  On the same date, CMSO purchased 79,488 shares of Common Stock.</footnote>
        <footnote id="F2">The 469,058 shares of Common Stock held by CMSI and the 1,026,772 shares of Common Stock held by CMSO may be deemed to be beneficially owned (i) indirectly by CMMC, as the investment adviser to CMSI and CMSO, (ii) indirectly by CMSI GP, as the general partner of CMSI, and CMSO GP, as the general partner of CMSO, respectively, and (iii) indirectly, on a shared basis, by the reporting person and the two other individual managing members of CMMC, the investment adviser to CMSI and CMSO, who share the power to direct the vote or disposition of such securities.  CMMC and the three individual managing members of CMMC have filed statements pursuant to Section 13 of the Securities Exchange Act of 1934, as amended, with respect to the securities of the Issuer which they may be deemed to beneficially own.  The reporting person's indirect interest in the securities reported herein (if any) is limited to his pecuniary interest in CMSI and CMSO (if any).</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ James Forbes Wilson</signatureName>
        <signatureDate>2010-09-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
