1.1 This specification covers carbon steel bars and shapes produced from standard rail steel. These bars are furnished in the as-wrought condition intended for structural use, or bar and shape uses, where high tensile properties are applicable. These materials are available in four strength levels as Grade 50, Grade 60, Grade 70, and Grade 80.

1.2 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.

1.3 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.