This specification deals with carbon and alloy steel forgings (including gas bottles) for use in thin-walled pressure vessels. Covered here are the following grades of steel forgings: Grade A; Grade B; Grade C; Grade D; Grade E, Classes 55, 65, and 70; Grade F, Classes 55, 65, and 70; Grade G, Classes 55, 65, and 70; Grade H, Classes 55, 65, and 70; Grade J, Classes 55, 65, and 70; Grade K; Grade L; Grade J, Class 110; and Grade M, Classes 85 and 100. Materials shall be manufactured by melting procedures, and optionally heat treated by normalization, normalization and tempering, or liquid-quenching and tempering. Heat and product analyses shall be performed wherein steel specimens shall conform to required chemical compositions of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, and vanadium. Steel materials shall also undergo bending, flattening and hardness tests and shall conform to required values of tensile strength, yield strength, elongation, and hardness. Forgings shall be subjected to magnetic particle examination as well.