1.1 This specification covers cold-formed welded high strength carbon steel or high strength low-alloy steel Hollow Structural Sections (HSS) or special shape structural tubing for welded, riveted, or bolted construction of bridges, buildings, and for structural purposes.1.2 This HSS is produced in welded sizes with a periphery of 64 in. [1626 mm] or less, and a specified wall thickness of 0.625 in. [16 mm] or less.Note 1: Products manufactured to this specification may not be suitable for those applications such as dynamic loaded elements in welded structures, etc. where low-temperature notch-toughness properties may be important. Inquire if dynamic loaded elements are required.1.3 The text of this specification contains notes and footnotes that provide explanatory material. Such notes and footnotes, excluding those in tables and figures, do not contain any mandatory requirements.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard.