In accordance with CSA G40.21, hollow sections — welded or seamless round, square, rectangular or special-profile structural tubing — are available in two classes: Class C Hollow sections that are cold-formed from a section produced either by a seamless process or by an automatic electric-welding process producing a continuous weld. Class H (i) Hollow sections made by a seamless or furnace-butt welding (continuous welding) or automatic electric-welding process, and hot-formed to final shape; or (ii) Hollow sections made by a seamless automatic electric welding process producing a continuous weld, and cold-formed to final shape; subsequently stress-relieved by heating to a temperature of 450°C (850°F) or higher, followed by cooling in air.
Description: General requirements for rolled or welded structural quality steel.
Intended use: General specification for plates, shapes, hollow sections, sheet, sheet piling, cold-formed channels and bars used in construction.
What are the benefits of Class H?