Metallus Inc

During the quarter ended March 31, 2024, officers (as defined in Exchange Act Rule 16a-1(f)) of the Company adopted written plans for the sale of the Company’s common shares intended to satisfy the affirmative defense conditions of Exchange Act Rule 10b5-1(c) (“Rule 10b5-1 trading arrangements”) as follows:

On March 6, 2024, Kristine C. Syrvalin, Executive Vice President, General Counsel and Chief Human Resources Officer, adopted a 10b5-1 trading arrangement that provides for the potential sale of up to 9,008 common shares, as well as up to 2,480 common shares acquired upon exercise of stock options, which trading arrangement is scheduled to start no earlier than June 6, 2024 and terminate no later than December 6, 2024.

On March 7, 2024, Kristopher R. Westbrooks, Executive Vice President and Chief Financial Officer, adopted a 10b5-1 trading arrangement that provides for the potential sale of up to 16,559 common shares, as well as up to 28,346 common shares acquired upon exercise of stock options, which trading arrangement is scheduled to start no earlier than June 10, 2024 and terminate no later than December 4, 2024.

Each of the above-named officers is currently and is expected to remain in compliance with his or her share ownership guidelines following the sale of any common shares pursuant to his or her 10b5-1 trading arrangement.