Since commencing full production in 1958, the mill has specialized in producing large steel sections for the construction industry. It has supplied steel for iconic structures such as The Shard in London and the new World Trade Center in New York.

In 1967 Dorman Long became part of the newly established British Steel Corporation. However the ownership was been changed over the years frequently.

In 2016 the works were sold to Greybull Capital, which rebranded it as British Steel Ltd. Subsequently, in 2020, British Steel was acquired by the Chinese Hebei Jingye Group.

In November 2023, British Steel announced plans to install an electric arc furnace adjacent to the mill, aiming to resume steelmaking on Teesside and enhance operational efficiency.