<SEC-DOCUMENT>0000089439-19-000144.txt : 20191210
<SEC-HEADER>0000089439-19-000144.hdr.sgml : 20191210
<ACCEPTANCE-DATETIME>20191210121818
ACCESSION NUMBER:		0000089439-19-000144
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20191206
FILED AS OF DATE:		20191210
DATE AS OF CHANGE:		20191210

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Christopher Gregory L.
		CENTRAL INDEX KEY:			0001341985

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06770
		FILM NUMBER:		191276955

	MAIL ADDRESS:	
		STREET 1:		8285 TOURNAMENT DRIVE, SUITE 150
		CITY:			MEMPHIS
		STATE:			TN
		ZIP:			38125

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MUELLER INDUSTRIES INC
		CENTRAL INDEX KEY:			0000089439
		STANDARD INDUSTRIAL CLASSIFICATION:	ROLLING DRAWING & EXTRUDING OF NONFERROUS METALS [3350]
		IRS NUMBER:				250790410
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1228

	BUSINESS ADDRESS:	
		STREET 1:		SUITE 100
		STREET 2:		150 SCHILLING BOULEVARD
		CITY:			COLLIERVILLE
		STATE:			TN
		ZIP:			38017
		BUSINESS PHONE:		(901)753-3200

	MAIL ADDRESS:	
		STREET 1:		SUITE 100
		STREET 2:		150 SCHILLING BOULEVARD
		CITY:			COLLIERVILLE
		STATE:			TN
		ZIP:			38017

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SHARON STEEL CORP
		DATE OF NAME CHANGE:	19910103
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_157599828054658.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-12-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000089439</issuerCik>
        <issuerName>MUELLER INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>MLI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001341985</rptOwnerCik>
            <rptOwnerName>Christopher Gregory L.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2530 JOHNSON ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GERMANTOWN</rptOwnerCity>
            <rptOwnerState>TN</rptOwnerState>
            <rptOwnerZipCode>38139</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board &amp; CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-12-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>22798</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>32.01</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>497658</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6800</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by children</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>83500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by trust where he is beneficiary</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>123500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by trust where wife is beneficiary</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This form reflects the sale of shares which may be deemed to be beneficially owned by the Reporting Person. The sale was effected pursuant to a previously disclosed Rule 10b5-1 trading plan.</footnote>
        <footnote id="F2">The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $32.00 to $32.01, inclusive.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Anthony Steinriede, Attorney-in-Fact</signatureName>
        <signatureDate>2019-12-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
