ALLOY STEEL 21/4 Ni possesses a combination of moderate strength and superior resistance to brittle fracture at subzero temperatures. It is one of the most economical materials for the construction of equipment to operate at temperatures as low as 90 F. It is intended primarily for welded pressure vessels. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-414. Producer or source: Alloy steel mills and foundries.