This specification covers cold-drawn buttweld carbon steel tubes for use as round, square, rectangular or special shape mechanical tubing. The carbon steel can be made unless a specific type of melting process is required by the purchaser. Heat and product analysis shall be made to determine the specified percentages of chemical elements to which steel tubes shall conform to. The tubing shall be free of injurious defects and shall have a workmanlike finish. Unless otherwise specified, both outside and inside surfaces of the tubing shall be coated with a film of rust-retarding oil before shipping.

1.1 This specification covers cold-drawn furnace-buttweld carbon steel tubes for use as mechanical tubing.

1.2 This specification covers round, square, rectangular, and special shape mechanical tubing.

1.3 Round tube size ranges covered are outside diameters up to 3 ¹/₂ in. [90 mm] and wall thickness from 0.035 to 0.500 in. [0.89 to 12.70 mm].

1.4 Optional supplementary requirements are provided and, when desired, shall be so stated in the order.

1.5 This product is available in various grades (Section 7   Tables 1 and 2 and conditions (Section 6).

1.6 Units—This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M specification designation (SI units), the inch-pound units shall apply. 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. The values stated in inch-pound units are to be regarded as standard. The values given in brackets are mathematical conversions to SI units that are provided for information only and are not considered 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.