ASTM F 688

This specification covers the requirements for wrought cobalt-35nickel-20chromium-10molybdenum alloy for use in the manufacture of surgical implants. The alloy shall be manufactured into plates, sheets, and foils in the annealed, cold-worked, or cold-worked and capability-aged condition. The plates may be available in ground or dull finish, while the sheet and foil may be of dull cold-rolled, bright cold-rolled, intermediate polished, general-purpose polished, dull satin finished, high luster finish, or mirror finish. In addition, plate edges may be of rolled edge or approximate square edge, while for sheet and foil, edges may be approximate square edge or an edge produced by slitting or shearing. Heat and product analyses as well as tests for ultimate tensile strength, yield strength, elongation, hardness, and average grain size shall be performed and shall conform to the requirements specified.