Cobalt Chrome Cobalt-chrome (Co-Cr) is a metal Alloy of cobalt and chromium. Cobalt-chrome has a very high specific strength and is commonly used in gas turbines, dental implants, and orthopedic implants. The Alloy composition used in orthopedic implants is described in industry standard ASTM-F75: cobalt with 27 to 30% chromium, 5 to 7% Molybdenum, and limits on other important elements such as manganese and silicon, less than 1%, iron, less than 0.75%, Nickel, less than 0.5%, and carbon, nitrogen, tungsten, phosphorus, sulfur, boron etc.[1] Besides cobalt-chromium-Molybdenum (Co-Cr-Mo), cobalt-Nickel-chromium-Molybdenum (Co-Ni-Cr-Mo) is also used for implants. The possible toxicity of released Ni ions from Co-Ni-Cr Alloys and also their limited frictional properties are a matter of concern in using these Alloys as articulating components. Thus, Co-Cr-Mo is usually the dominant Alloy for total joint arthroplasty.