1.1 本规范涵盖用于桥梁和建筑物的焊接、铆接或螺栓连接施工以及一般结构用途的冷成型焊接和无缝碳钢圆形、方形、矩形或特殊结构管状型材。 1.2 这种管子有焊接和无缝两种尺寸，外围尺寸为88英寸。[2235 mm]或更小，且规定壁厚为1.000 in。[25.4毫米]或更小。D级需要热处理。 注1: 按照本规范制造的产品可能不适用于焊接结构中的动态加载元件等应用，在这些应用中，通常通过夏比冲击试验测量的低温缺口韧性性能可能很重要。 其他ASTM标准也有CVN要求，可能更适合这些应用。 1.3 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。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。除非订单中规定了本规范的“M”名称，否则英寸-磅单位应适用。 1.4 本规范的文本包含提供解释材料的注释和脚注。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。 1.5 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 cold-formed welded and seamless carbon steel round, square, rectangular, or special structural tubular shapes for welded, riveted, or bolted construction of bridges and buildings, and for general structural purposes. 1.2 This tubing is produced in both welded and seamless sizes with a periphery of 88 in. [2235 mm] or less, and a specified wall thickness of 1.000 in. [25.4 mm] or less. Grade D requires heat treatment. Note 1: Products manufactured to this specification may not be suitable for those applications such as dynamically loaded elements in welded structures, etc., where low-temperature notch-toughness properties, which are typically measured by Charpy Impact testing, may be important. There are other ASTM standards that do have CVN requirements and may be more suitable for those applications. 1.3 The values stated in either SI units or inch-pound 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 non-conformance with the standard. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order. 1.4 The text of this specification contains notes and footnotes that provide explanatory material. Such notes and footnotes, excluding those in tables and figures, do not contain any mandatory requirements. 1.5 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.