<SEC-DOCUMENT>0001666138-21-000033.txt : 20210201
<SEC-HEADER>0001666138-21-000033.hdr.sgml : 20210201
<ACCEPTANCE-DATETIME>20210201164412
ACCESSION NUMBER:		0001666138-21-000033
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210128
FILED AS OF DATE:		20210201
DATE AS OF CHANGE:		20210201

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VanArsdale William
		CENTRAL INDEX KEY:			0001674326

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-37793
		FILM NUMBER:		21577291

	MAIL ADDRESS:	
		STREET 1:		16100 SOUTH LATHROP AVENUE
		CITY:			HARVEY
		STATE:			IL
		ZIP:			60426

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Atkore International Group Inc.
		CENTRAL INDEX KEY:			0001666138
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS ELECTRICAL MACHINERY, EQUIPMENT & SUPPLIES [3690]
		IRS NUMBER:				900631463
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		16100 SOUTH LATHROP AVENUE
		CITY:			HARVEY
		STATE:			IL
		ZIP:			60426
		BUSINESS PHONE:		7083391610

	MAIL ADDRESS:	
		STREET 1:		16100 SOUTH LATHROP AVENUE
		CITY:			HARVEY
		STATE:			IL
		ZIP:			60426
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_161221582899697.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-01-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001666138</issuerCik>
        <issuerName>Atkore International Group Inc.</issuerName>
        <issuerTradingSymbol>ATKR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001674326</rptOwnerCik>
            <rptOwnerName>VanArsdale William</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>16100 SOUTH LATHROP AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HARVEY</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60426</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</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2021-01-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2597</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25204</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects the award of restricted stock units (&quot;RSUs&quot;) granted to Director on January 28, 2021. These RSUs are scheduled to vest based on continued service as a Director on the earlier of (a) the day immediately preceding the first anniversary of the grant date and (b) the day immediately preceding the Atkore International Group Inc. annual meeting of stockholders next following the grant date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Daniel S. Kelly, Attorney-in-Fact for William VanArsdale</signatureName>
        <signatureDate>2021-02-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
