<SEC-DOCUMENT>0001172661-20-000694-index.html : 20200214
<SEC-HEADER>0001172661-20-000694.hdr.sgml : 20200214
<ACCEPTANCE-DATETIME>20200214130421
ACCESSION NUMBER:		0001172661-20-000694
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20200214
DATE AS OF CHANGE:		20200214

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALLEGHENY TECHNOLOGIES INC
		CENTRAL INDEX KEY:			0001018963
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL PIPE & TUBES [3317]
		IRS NUMBER:				251792394
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-46715
		FILM NUMBER:		20617177

	BUSINESS ADDRESS:	
		STREET 1:		1000 SIX PPG PLACE
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222
		BUSINESS PHONE:		4123942800

	MAIL ADDRESS:	
		STREET 1:		100 SIX PPG PLACE
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ALLEGHENY TELEDYNE INC
		DATE OF NAME CHANGE:	19960716

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FRONTIER CAPITAL MANAGEMENT CO LLC
		CENTRAL INDEX KEY:			0001216488
		IRS NUMBER:				043492668
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		99 SUMMER STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>frontier-ati123119a2.htm
<DESCRIPTION>SCHEDULE 13G HOLDINGS REPORT AMENDMENT
<TEXT>
Document 1 - file: frontier-ati123119a2.htm

</DOCUMENT>
</SEC-DOCUMENT>