1.1 This specification covers several grades of carbon and alloy steel seamless mechanical tubing. The grades are listed in Tables 1-3. When welding is used for joining the weldable mechanical tube grades, the welding procedure shall be suitable for the grade, the condition of the components, and the intended service. 1.2 This specification covers both seamless hot-finished mechanical tubing and seamless cold-finished mechanical tubing in sizes up to and including 12 3/4 in. (323.8 mm) outside diameter for round tubes with wall thicknesses as required. 1.3 The tubes shall be furnished in the following shapes, as specified by the purchaser: round, square, rectangular, and special sections. 1.4 Supplementary requirements of an optional nature are provided and when desired shall be so stated in the order. 1.5 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.