AK 420 martensitic stainless steel has good corrosion resistance with increased strength over other 400 martensitic stainless steels. The alloy is magnetic. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1212. Producer or source: AK Steel Corporation.