X0306 4 2020-05-12 0 0001018963 ALLEGHENY TECHNOLOGIES INC ATI 0001241243 HARVEY J BRETT 1000 SIX PPG PLACE PITTSBURGH PA 15222 1 0 0 0 Common Stock, par value $0.10 per share 2020-05-12 4 A 0 21214 0.00 A 70912.815 D Common Stock, par value $0.10 per share 2020-05-13 4 F 0 36 6.73 D 70876.815 D Annual Director award under the Issuer's 2020 Incentive Plan as part of the Issuer's Director compensation program. Includes 13,577 shares representing Mr. Harvey's annual director award and 7,637 shares that Mr. Harvey elected, in December 2019, to receive in lieu of a portion of his 2020 cash retainer. Annual Director award granted under the Issuer's 2020 Incentive Plan as part of the Issuer's Director compensation program. Shares withheld for payment of taxes in connection with the May 13, 2020 vesting of restricted stock granted in May 2019. Represents the average of the high and low trading prices for one share of the Issuer's common stock on the New York Stock Exchange on May 13, 2020. /s/ Elliot S. Davis, Attorney-in-Fact for J. Brett Harvey 2020-05-14