This specification covers the standard for martensitic stainless steel for various structural, architectural, pressure vessel, and heat-resisting applications. The material shall undergo heat-treatment by tempering. The steel shall conform to the requirements as to chemical composition specified for carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel, molybdenum, and nitrogen. Mechanical testing shall be performed on the steel and shall conform to the specified values in mechanical properties such as yield strength, tensile strength, elongation, and Brinell hardness.