Stainless steel is an alloy composed of varying amounts of manganese, silicon, chromium, and low-carbon steel. The chromium content in stainless steel provides lasting corrosion resistance in oxygenated environments and extreme temperatures and can deliver exceptional durability when hardened. While stainless steel is typically an alloy composed of the four components above, select grades add molybdenum and nickel to improve the corrosion resistance. While there are several compositions, for a steel alloy to be considered stainless steel, it must contain 10.5% chromium or more.