1.1 本规范适用于汽车比赛用无缝冷加工碳钢圆形结构框架管。化学要求列于 表1 . 管道可用于要求类似公差和特性的其他应用。本规范包括热处理和机械性能要求，以满足应用需求。管子拟通过焊接进行弯曲和连接。焊接工艺应适用于等级、部件状况和预期用途。 1.2 管子外径尺寸范围为0.625至2.0英寸。[16至50毫米]。壁厚应规定为最小壁厚。 1.3 可以提供可选的补充要求，当需要其中一个或多个时，应在订单中说明每个补充要求。 1.4 以英寸-磅单位或国际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。 1.5 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.6 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 is for seamless cold-finished carbon steel round structural frame tubing for automotive racing applications. The chemical requirements are listed in Table 1 . Tubing may be used for other applications requiring similar tolerances and properties. The specification includes requirements for heat treatment and mechanical properties to meet the needs for the application. The tubing is intended to be bent and joined by welding. The welding procedure shall be suitable for the grade, the condition of the components, and the intended service. 1.2 The tubing outside diameter size range is from 0.625 to 2.0 in. [16 to 50 mm]. The wall thickness shall be specified as a minimum wall. 1.3 Optional supplementary requirements may be provided and, when one or more of these are desired, each shall be so stated in the order. 1.4 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 non-conformance with the standard. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.6 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.