1.1 This specification covers carbon steel track bolts and carbon steel nuts for use in conjunction with joint bars to connect rails in railroad track. 1.2 Two grades of track bolts are defined: 1.2.1 Grade 1, Low-Carbon, Untreated, primarily for industrial and mine track use. 1.2.2 Grade 2, Heat-Treated, for general track use. 1.3 Two grades of nuts are defined: 1.3.1 Grade 1, Low-Carbon or Soft Steel, primarily for application on Grade 1 track bolts. 1.3.2 Grade 2, Medium-Carbon, for general application on track bolts. 1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.