MUELLER Alloy No. 6300 (formerly MBCo. Alloy 224K and sometimes called Tuf-Stuf Alloy) is a heat-treatable aluminum bronze containing 5% nickel. It is intended for those applications requiring combinations of corrosion resistance, excellent bearing properties at considerable loads, and extremely high strength both at room and elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-361. Producer or source: Mueller Brass Company.