This specification deals with the standard requirements for heat-treated alloy steel axles and solid design roller bearing axles with machined bodies for mass transit and commuter cars in electric and locomotive hauled railway service. Various axle designs are used for this service including motor and non-motor with either inboard or outboard journals. Materials shall be forged, cooled and heat treated by normalizing, liquid quenching, tempering, and straightening. Steels shall conform to chemical composition requirements specified for each of the seven classes considered here. Conformance to mechanical property requirements such as tensile strength, yield strength, elongation, and reduction of area, shall be evaluated by tensile tests. Details of nondestructive ultrasonic and magnetic particle examination procedures are discussed thoroughly. Final axle products shall conform to purchaser-specified size, shape, and finish. Rough machining shall be free of excessively rough ridges and coarse chatter marks, and the finish machined axle surfaces shall be free of injurious imperfections.

1.1 This specification covers heat-treated carbon and alloy steel axles for mass transit and commuter cars in electric and locomotive hauled railway service.

1.2 This specification is for solid design roller bearing axles with machined bodies.

1.3 Various axle designs are used for this service including motor and non-motor with either inboard or outboard journals.

1.4 Supplementary requirements including those in the general requirements of Specification A788/A788M are provided for use when additional testing or inspection is desired. These shall apply only when specified individually by the purchaser in the order.

1.5 Unless the order specifies the applicable “M” specification designation, the axles shall be furnished to the inch-pound units.

1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.