440A (Annealed) is a high carbon martensitic stainless steel that is AOD melted. This alloy can be heat treated to extremely high hardnesses. It has slightly less carbon than 440B and 440C giving it better machinability, but less hardness. This material is typically used for parts requiring hardness up to 55 HRC and resistance to wear, corrosion, and oxidation. The combination of good wear resistance and high hardness makes this alloy an excellent candidate for cutting tools and knife blades. It also is often used for dental and surgical equipment. (UNS S44002)
