1.1 本规范涵盖圆形、方形、矩形和特殊形状的电阻焊接碳钢机械管，焊接后镀锌或由铝涂层、镀锌（镀锌）、锌铁合金涂层（镀锌）制成，55 % 铝-锌合金涂层或锌-铝-镁合金涂层的碳钢板。本规范不包括用作电气导管（EMT）或中间金属导管（IMC）的管道。 1.1.1 根据化学要求，该产品有各种等级（第节 5. 和 9 ). 1.1.2 该产品有多种类型（第节 3. ). 1.2 本规范涵盖外径或最大外径范围为 1. / 2. 至15英寸。[12.7至380.0 mm]，壁厚0.028至0.180 in。[0.70至4.60 mm]。 可订购不确定的壁厚。在这些情况下，应采用表3、4、5、6、12和13中更严格的公差。 1.3 订购上述范围内的尺寸时，应满足本规范的所有其他要求。 1.4 本规范以英寸磅单位和国际单位制表示；但是，除非采购订单规定了适用的M规格名称（SI单位），否则应采用英寸磅单位。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，SI单位显示在括号中。每个系统中规定的值可能不完全相等；因此，每个系统应独立使用。合并两个系统的值可能导致不符合标准。 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《国际标准、指南和建议制定原则决定》中确立的国际公认标准化原则制定的。

1.1 This specification covers round, square, rectangular, and special shape, electric-resistance-welded carbon steel mechanical tubing, either zinc-coated (galvanized) after welding or produced from aluminum-coated, zinc-coated (galvanized), zinc-iron alloy-coated (galvannealed), 55 % aluminum-zinc alloy-coated, or zinc-aluminum-magnesium alloy-coated carbon steel sheet. Tubing for use as electrical conduit (EMT) or intermediate metallic conduit (IMC) is not covered by this specification. 1.1.1 The product is available in various grades based on chemical requirements (Sections 5 and 9 ). 1.1.2 The product is available in various Types (Section 3 ). 1.2 This specification covers mechanical tubing with outside diameters or maximum outside dimensions ranging from 1 / 2 to 15 in. [12.7 to 380.0 mm] and wall thickness from 0.028 to 0.180 in. [0.70 to 4.60 mm]. Indeterminate wall thicknesses may be ordered. In those cases the more stringent tolerances of Tables 3, 4, 5, 6, 12 and 13 shall apply. 1.3 When sizes within the ranges listed above are ordered, all other requirements of the specification shall be met. 1.4 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order specifies the applicable M specification designation (SI units), the inch-pound units shall apply. 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. 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.