1.1 This specification covers three grades of seam-welded, round, tapered steel tubes for structural use. Grades A and B are of low-carbon steel composition and Grade C is of weather-resistant steel composition.

1.2 This tubing is produced in welded sizes in a range of diameters from 2 1/2 to 30 in. (63.5 to 762.0 mm) inclusive. Wall thicknesses range from 0.1046 to 0.375 in. (2.66 to 9.53 mm). Tapers are subject to agreement with the manufacturer.

1.3 The values stated in inch-pound units are to be regarded as the standard.