X0306 4 2020-02-26 0 0001018963 ALLEGHENY TECHNOLOGIES INC ATI 0001332656 Powers Elizabeth C 1000 SIX PPG PLACE PITTSBURGH PA 15222 0 1 0 0 Senior VP, CHRO Common Stock, par value $0.10 per share 2020-02-26 4 F 0 2808 18.62 D 110260.8834 D Common Stock, par value $0.10 per share 2020-02-27 4 F 0 2099 18.12 D 108161.8834 D Shares withheld for payment of taxes on performance/restricted stock granted in 2015 that vested on February 26, 2020. 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 February 26, 2020. This amount includes 1,921.0769 shares of common stock that Ms. Powers owns in the Company's 401(k) Plan. Fluctuations in 401(k) share amounts reflect the Plan's unit reporting method. Ms. Powers holds approximately 1,610 units, which represent interests in the Company's stock fund. Shares withheld for payment of taxes on restricted stock units awarded on February 27, 2019. One-third of such restricted stock units vested by their terms on February 27, 2020. 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 February 27, 2020. /s/ Elliot S. Davis, Attorney-in-Fact for Elizabeth C. Powers 2020-02-28