AK Steel is closing three production operations in Dearborn, Mich., because of "rapidly deteriorating business conditions."
The company's annealing, hot strip mill and tempering operations will cease July 5. The plants have 343 workers in the Detroit suburb.
The decision came down from the company's parent company, Cleveland-Cliffs.
Cleveland-Cliffs finalized a merger with AK Steel in March 2020.
The company mines iron ore and makes steel. It owns five other production facilities in the Midwest.