Metallus Inc

During the quarter ended December 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 November 14, 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 15,000 common shares, which trading arrangement is scheduled to start no sooner than March 3, 2025 and terminate no later than September 3, 2025.

On November 16, 2024, Michael S. Williams, President and Chief Executive Officer, adopted a 10b5-1 trading arrangement that provides for the potential sale of up to 100,000 common shares, which trading arrangement is scheduled to start no sooner than March 6, 2025 and terminate no later than September 19, 2025.

On November 18, 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 12,000 common shares and up to 12,104 common shares acquired upon the exercise of stock options, which trading arrangement is scheduled to start no sooner than March 6, 2025 and terminate no later than September 8, 2025.

On December 5, 2024, Nicholas A. Yacobozzi, Chief Accounting Officer, adopted a 10b5-1 trading arrangement that provides for the potential sale of up to 21,974 common shares, which trading arrangement is scheduled to start no sooner than March 6, 2025 and terminate no later than September 8, 2025.

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.