UGI 4057 Air is a carbon martensitic stainless steel with nickel for aerospace applications. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1247. Producer or source: Schmolz + Bickenbach USA Inc..