1.1 本规范涵盖由标准钢轨钢生产的碳钢棒材和型材。这些钢筋在锻造状态下提供，用于结构用途或钢筋和形状用途，其中高拉伸性能适用。这些材料有四种强度等级，分别为50级、60级、70级和80级。 1.2 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

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.