... , rectangle, ellipse, semicircle, arch, sector, triangle, hexagon and octagon, etc Square Hollow Section Pipe/Steel Pipe/Tube 1 ... , rectangle, ellipse, semicircle, arch, sector, triangle, hexagon and octagon, etc 5-Available Diameter 20-600mm or other requests6 ... products are widly used in machinery, raod and construction fields, lifter, tower crane, automobile and structure, etc. 9- Other products: ...