Steel structures built with steel tubes leverage the excellent properties of tubular profiles to resist the efforts of compression, torsion and Flex in all directions. With regard to the strength and stability, tubular sections present superiority with regard to other families of steel sections. In particular, closed circular hollow sections have the section more efficient before torques, having distributed all his material around the polar axis. The torque of the tubular section profiles module is 200 to 300 times greater than that of the open section profiles. Already for some time, the branches of bamboo, by its tubular structure, were converted into light building materials that took advantage of all these benefits. In the 19th century, along with the development of the steel industry, arose the first methods of manufacture of pipes with circular hollow sections at the same time that developed the manufacture of classic open sections hot rolled (I, L and U profiles). Circular section tubes are manufactured from a solid steel block, where the resulting tubes are not soldiers. In the case of circular welded tubes, piping is manufactured or from a flat plate.
The circular steel tubes manufacturing process is virtually the same in the case of use as fluid conduction or structural element. However, the Stewart & Lloyds, in the United Kingdom in 1952, was the pioneer in the industrial production of rectangular hollow section profiles. Section cuadrada, rectangular, hexagonal or octagonal tubes, are obtained from deformation, both hot and cold, a tube circulate as part to comply. For this reason, tube is passed through a few cylinders of conformation working in series providing the original hose as required. In the selection of a profile particularly in a steel structure depend on aspects such as advantages and disadvantages regarding mechanical properties, unitary cost of material and manufacture, installation and maintenance costs.