This specification covers gray iron castings for products of the automobile, truck, tractor and allied industries. The materials shall be classified into eight grades (G1800, G2500, G3000, G3500, G4000, G2500a, G3500b and G3500c) based on the range of their casting hardness, chemical composition and microstructure. Grades G1800 and G2500 shall be annealed. Alloy gray iron automotive camshafts of grade designation G4000d shall conform to the required values of casting hardness, chemical compositions of chromium, molybdenum, and nickel and microstructure. The cam areas of camshaft casting shall undergo selective hardening by flame or induction hardening and shall conform to the required values of depth and surface hardness.

1.1 This specification applies to gray iron castings, cast in sand molds, used in the products of the automobile, truck, tractor, and allied industries.

1.2 The values stated in inch-pound units are to be regarded as the standard.