G-E ALLOY X-63 is a cobalt-base alloy having excellent oxidation and corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on high temperature performance and corrosion resistance as well as heat treating, machining, and joining. Filing Code: Co-19. Producer or source: General Electric Company, Metallurgical Products Department. Originally published March 1960, revised June 1963.