MUELLER Alloy 4820 is a copper-zinc alloy (brass) containing a medium amount of lead (0.4-1.0%) to make it free machining. It has a good combination of strength and ductility. Its good resistance to corrosion by salt water makes it suitable for marine applications. It also is used for screw machine products and fasteners. 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-436. Producer or source: Mueller Brass Company.