Hollow Section steel Tube is the general name for the steel pipe other than thecircular steel pipe. Such as square, rectangle, oval,elliptical, cone, trapezoidal, spiral, etc. Different steel pipe can more adapt to the particularity of use conditions, save metal and improve the labor productivity of parts manufacturing. It is widely used in aviation, automobile, shipbuilding, mining machinery, agricultural machinery, construction, light textile and boiler manufacturing. The methods of producing different pipes are cold pulling, electric welding, extrusion and hot rolling, etc. Compared with the round tube, the different tubes generally have a larger moment of inertia and cross section modulus, and have a large bending resistance and torsion resistance, which can greatly reduce the structural weight and save steel.