This specification covers the minimum welding requirements applicable to welded structures and cast components used in the railroad industry. It is not intended to apply to tank car tanks nor to the welding of rails. Recommended practices for welding railroad rails and related components are included in D15.2, Recommended Practice for the Welding of Rails and Related Rail Components for Use by Rail Vehicles. Specifications for welding tank car tanks and components welded directly thereto are outlined in the AAR Manual of Standards and Specifications for Welding, Section C—Part III, Specification M-1002 (AAR M-1002 C-III).

Welding symbols shall be those shown in the latest edition of AWS A2.4, Standard Symbols for Welding, Brazing, and Nondestructive Examination.