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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-07-16</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001533526</issuerCik>
        <issuerName>GLOBAL BRASS &amp; COPPER HOLDINGS, INC.</issuerName>
        <issuerTradingSymbol>BRSS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001365411</rptOwnerCik>
            <rptOwnerName>Whitaker Ronald C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>475 N. MARTINGALE ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 1200</rptOwnerStreet2>
            <rptOwnerCity>SCHAUMBURG</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60173</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2019-07-16</value>
                <footnoteId id="F1"/>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>U</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>30207</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>44</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On April 9, 2019, Global Brass and Copper Holdings, Inc. (the &quot;Company&quot;) entered into an Agreement and Plan of Merger (the &quot;Merger Agreement&quot;) with Wieland Holdings, Inc., an Illinois corporation (&quot;Parent&quot;), Elephant Acquisition Corp., a Delaware corporation and wholly owned Subsidiary of Parent (&quot;Merger Sub&quot;) and Wieland-Werke Aktiengesellschaft, a German stock corporation (&quot;Parent Holdco&quot;), pursuant to which Parent Holdco would acquire the Company. On July 16, 2019, pursuant to the Merger Agreement, Merger Sub merged with and into the Company, with the Company continuing as the surviving corporation and a wholly-owned indirect subsidiary of Parent (the &quot;Merger&quot;).</footnote>
        <footnote id="F2">As consideration for the Merger, each share of common stock of the Company (the &quot;Shares&quot;) (other than Shares owned by the Company in treasury or by Parent Holdco, Parent or Merger Sub, or any wholly owned subsidiary of Parent Holdco (other than Parent and Merger Sub)) was automatically canceled and converted into the right to receive an amount in cash equal to $44, without interest thereon and less any applicable withholding taxes.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Anne-Marie W. D'Angelo, as Attorney-in-Fact</signatureName>
        <signatureDate>2019-07-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
