ATI 6-4 ELI, also known as Grade 23, is a higher purity grade of ATI Ti-6Al-4V for use in surgical and medical applications. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: Ti-159. Producer or source: Allegheny Technologies Inc..