1.1 本规范涵盖两个等级，36[250]和50[345]，用于建筑框架或一般结构用途的低屈服拉伸比轧制钢结构型材和板材。 1.2 法兰宽度为6英寸的所有形状型材。规范中描述的[150 mm]及以上 A6/A6M 附件A2和小于等于5英寸的板。本规范包括[125 mm]厚。 1.3 在买方要求进行额外测试或附加限制的情况下，提供了补充要求。 此类要求仅在采购订单中规定时适用。 1.4 当焊接钢材时，应采用适合钢材等级和预期用途或服务的焊接工艺。见规范附录X3 A6/A6M 有关焊接性的信息。 1.5 本规范的文本包含注释或脚注，或两者兼有，以提供解释性材料；此类注释和脚注（不包括表和图中的注释和脚注）不包含任何强制性要求。 1.6 以英寸为单位的数值- 磅单位或国际单位应单独视为标准。在文本中，国际单位显示在括号中。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 1.7 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 two grades, 36 [250] and 50 [345] of rolled steel structural shapes and plates with low yield to tensile ratio for use in building framing or for general structural purposes. 1.2 All shape profiles with a flange width of 6 in. [150 mm] and greater described in Specification A6/A6M , Annex A2, and plates up to and including 5 in. [125 mm] thick are included in this specification. 1.3 Supplementary requirements are provided for use where additional testing or additional restrictions are required by the purchaser. Such requirements apply only when specified in the purchase order. 1.4 When the steel is to be welded, a welding procedure suitable for the grade of steel and intended use or service is to be utilized. See Appendix X3 of Specification A6/A6M for information on weldability. 1.5 The text of this specification contains notes or footnotes, or both, that provide explanatory material; such notes and footnotes, excluding those in tables and figures, do not contain any mandatory requirements. 1.6 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.7 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.