Stainless steel 440C, also known as UNS S44004, principal elements are .95% to 1.2% carbon, 16% to 18% chromium, .75% nickel, with traces of manganese, silicon, copper, molybdenum, phosphorus and sulfur. Grade 440C is a high carbon martensitic stainless with moderate corrosion resistance good strength, and the ability to obtain and hold excellent hardness (Rc 60) and wear resistance. It is considered to be slightly cold workable by common practices and does respond to heat treatment.