NITRALLOY 125 (0.20-0.30% C) is a special alloy steel which can be nitrided, that is, surface hardened, without final quenching, by the action of ammonia gas at relatively low temperatures. Nitralloy 125 is also known as Nitralloy H. 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, machining, and joining. Filing Code: SA-61. Producer or source: Alloy steel mills and foundries.