X0306 4 2017-02-23 0 0001018963 ALLEGHENY TECHNOLOGIES INC ATI 0001594792 DeCourcy Patrick J 1000 SIX PPG PLACE PITTSBURGH PA 15222 0 1 0 0 Senior VP, Finance and CFO Common Stock, $0.10 par value 2017-02-23 4 A 0 14815 0.00 A 99843.9276 D Common Stock, $0.10 par value 2017-02-23 4 F 0 542.7985 19.44 D 99301.1291 D Common Stock, $0.10 par value 2017-02-27 4 F 0 2571 19.65 D 96730.1291 D Award of restricted stock units, which are settled in shares of stock upon vesting. The award vests in three equal annual installments on each of the first three anniversaries of the grant date. Shares withheld for payment of taxes on shares of previously-restricted stock awarded on February 23, 2012, the restrictions on which lapsed by their terms on the fifth anniversary of the grant date. 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 23, 2017. Shares withheld for payment of taxes on restricted stock units awarded on February 27, 2016. One-third of such restricted stock units vested by their terms on February 27, 2017. 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, 2017. /s/ Elliot S. Davis, Attorney-in-Fact for Patrick J. DeCourcy 2017-02-27