MUELLER Alloy 6421 is a modification of MUELLER Alloy No. 6420 (Alloy Digest Cu-266, February 1973). Alloy 6421 has the same general properties as Alloy 6420 but with somewhat superior ductility and resistance to corrosion. Alloy 6421 has extremely good resistance to corrosion, high strength, excellent ductility, good machinability and good hot-working characteristics. Its applications include aircraft and marine bushings, nuts, bolts, and pickling equipment. 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, machining, and joining. Filing Code: Cu-471. Producer or source: Mueller Brass Company.