1. Scope 1.1 This specification covers steel joint bars for connecting steel rails in mine, industrial, and standard railroad track. 1.2 Three grades of joint bars are defined for applications where non-heat treated bars are suitable: 1.2.1 Grade 1, low-carbon, primarily for industrial and mine use. 1.2.2 Grade 2, medium-carbon, primarily for industrial and mine use. 1.2.3 Grade 3, high-carbon, for general use in standard railroad track. They may be used in the production of insulated track joints. 1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.