Firth Brown NCMI is a tough, shock resisting, oil hardening nickel-chromium-molybdenum steel having the highest combination of tensile and endurance strengths along with ductility. It is recommended for heavy duty service parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-247. Producer or source: Firth Brown Ltd, Atlas Works.