AMPCOLOY 91 Alloy is a cobalt-bearing copper alloy with a small addition of beryllium to make it age hardenable. It has an excellent combination of strength, toughness and electrical conductivity. It is recommended for resistance welding tips and wheels; flash, butt and projection welding dies; springs; slip and collector rings; and electrical components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-286. Producer or source: Ampco Metal Inc..