Cold Rolled Steel Square Bar is a common bar stock with many applications. It is measured by taking its thickness or its width which are the same. It is characterized by its sharper corners, as opposed to Hot Rolled Square Bar, which has slightly rounded edges. C1018 Cold Finish Square, is a rolled steel product with close dimensional accuracy, smooth surface finish, and increased mechanical properties and machinability. C1018 Cold Finish Square is a general purpose low carbon steel with good case hardening qualities and is especially suited for cold forming and bending.