This specification covers minimum-wall-thickness carbon steel tubes proposed for use in heat exchangers, condensers, and similar heat-transfer apparatus. The materials under this specification shall be in accordance with other ASTM document enlisted herein unless otherwise provided. The tubes shall be manufactured by electric-resistance welding and shall undergo heat treatment. Mechanical testing of the specimens shall include a flattening test, flange test and a reverse flattening test. The specimens shall also be subjected to Brinell or Rockwell hardness test and hydrostatic or nondestructive electric test.

1.1 This specification2 covers minimum-wall-thickness, electric-resistance-welded, carbon steel tubes to be used for heat exchangers, condensers, and similar heat-transfer apparatus.

1.2 The tubing sizes usually furnished to this specification are to 3 in. [76.2 mm] in outside diameter, inclusive. Tubing having other dimensions may be furnished, provided such tubes comply with all other requirements of this specification.

1.3 Mechanical property requirements do not apply to tubing smaller than ¹/₈ in. [3.2 mm] in inside diameter or 0.015 in. [0.4 mm] in thickness.

1.4 The purchaser shall specify in the order the outside diameter and minimum wall thickness. The inside diameter shall not be specified.

1.5 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 are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order.

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.