This specification covers austenitic gray iron castings that are used primarily for their resistance to heat, corrosion, and wear. The types of castings covered here are: Type 1, Type 1b, Type 2, Type 2b, Type 3, Type 4, Type 5, and Type 6. The materials shall be manufactured by melting in any furnace that produces castings which includes cupolas, air furnaces, electric furnaces, crucible furnaces, and so forth. Heat and product analyses shall be performed wherein specimens shall conform to required chemical composition of carbon, silicon, manganese, nickel, copper, chromium, sulfur, and molybdenum. The materials shall undergo a nonmagnetic test which is based on the material's attraction to a small steel horseshoe-type magnet and a magnetic permeability test in the event that nonmagnetic castings are specified. Tension tests shall be performed wherein specimens shall conform to required tensile strength and Brinell hardness.