Allegheny Ludlum No. 2 and No. 5 relay steels are iron/silicon alloys. They are soft magnetic alloys that combine high magnetic permeability, low residual magnetization and low coercive force with good mechanical properties and fabricability. This datasheet provides information on composition and physical properties. It also includes information on forming, heat treating, and machining. Filing Code: Fe-97. Producer or source: Allegheny Ludlum Corporation.