1.1 This specification covers nonheat-treated axles up to and including those 6 1/2 in. (165.1 mm) nominal diameter at the center and heat-treated axles of all sizes for freight cars, passenger cars, and locomotives.

1.2 This specification is for axles with machined bodies. For axles with as-forged bodies, see Specification A383.

1.3 The grades of carbon steel axles are as follows:

1.3.1 Grade U -Nonheat-treated.

1.3.2 Grade F -Double normalized and tempered. (All freight axles over 6 1/2 in. (165.1 mm) nominal diameter at the center shall be Grade F.)

1.3.3 Grade G -Quenched and tempered.

1.3.4 Grade H -Normalized, quenched, and tempered.

1.3.5 Grades F, G, and H axles are used in heavy-duty service on locomotives, cars, and other equipment.

1.4 Typical designs for plain and roller bearing axles are shown in the Manual of Standards and Recommended Practice of the Association of American Railroads.

1.5 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only when specified individually by the purchaser in the order.

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