Hollow Sections

  A hollow structural section (HSS) is a type of metal profile with a hollow tubular cross section. In some countries they are referred to instead as a structural hollow section (SHS). Most HSS are of circular or rectangular section, although other shapes are available, such as elliptical. They normally comprise structural steel, although are also available in stainless steel, aluminium and other materials. HSS is sometimes mistakenly referenced as hollow structural steel. Rectangular HSS are also called tube steel or structural tubing. Circular HSS are sometimes mistakenly called steel pipe though true steel pipe is actually dimensioned and classed differently than HSS. The corners of HSS are heavily rounded, or chamfered, at radii approximately twice the wall thickness. The wall thickness is uniform around the section. Square HSS is made the same way as pipe. During the manufacturing process flat steel plate is gradually changed in shape to become round where the edges are presented ready to weld. The edges are then welded together to form the mother tube. During the manufacturing process the mother tube goes through a series of shaping stands and cold forms the round HSS (mother tube) into the final round, square, or rectangular shape. Most American manufacturers adhere to the ASTM A500 standard, while Canadian manufacturers follow both ASTM A500 and CSA G40.21. European hollow sections are generally in accordance with the EN 10210 standard.