This specification covers seamless cold-finished carbon steel round structural frame tubing for automotive racing applications. Tubing may be used for other applications requiring similar tolerances and properties. 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.

This specification includes requirements for materials and manufacturing process to be used, the chemical composition of carbon steel, heat treatment, product analysis, tensile properties, additional mechanical testing (flare test, flatten test), nondestructive eddy current test, workmanship, finish, and appearance. It also provides guidance for coating, packaging, and product and package marking.

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 and health practices and determine the applicability of regulatory limitations prior to use.