This specification covers a group of common requirements that are mandatory for steel castings produced by the investment casting process for pressure-containing parts. Master heats shall be made by the electric furnace process with or without separate refining such as argon-oxygen-decarburization (AOD), vacuum-oxygen degassing (VOD), vacuum-induction-melting (VIM). Ferritic and martensitic steel shall be cooled after pouring to provide complete transformation of austenite prior to heat treatment to enhance mechanical properties. Chemical, heat, and product analyses shall be performed and the chemical composition thus determined shall conform to the prescribed values in carbon, manganese, silicon, phosphorus, sulfur, nickel, chromium, molybdenum, vanadium, tungsten, copper, and aluminum. Tensile testing shall be done on the castings and shall meet the required yield and tensile strength, elongation, and reduction of area. Each casting shall also be tested after machining to hydrostatic shell pressure test and shall not show any leaks.