The most obvious difference between square pipe and circular pipe is its cross section. A square pipe is a circular square pipe. The square tube belongs to the forming tube. Compared with circular pipe, non-circular pipe with cross-section has larger moment of inertia and modulus of cross-section, greater flexural and torsional resistance, superior structure, can reduce its own gravity and save the advantages of steel. Therefore, square pipes are widely used in construction, machinery manufacturing, steel structure engineering, shipbuilding, solar support, steel structure engineering, electric power engineering, power plant, agricultural machinery, glass curtain wall, automobile chassis, airport, boiler and so on. Construction, highway railings, construction, pressure vessels, oil storage tanks, bridges, power plant equipment, lifting and transportation machinery and other high-load welding structural parts. The purpose of circular pipes is mainly to be used in general low-pressure fluid pipelines, such as water, natural gas and oil. It is also used for oil well and tubing in the petroleum industry, especially for coal in offshore oilfields, oil heaters, condensers and chemical coking equipment. Pipes for distillate oil exchangers, bridge pipe piles, support pipes for mine tunnels, etc.


Welded pipes are used in most pipeline systems and building steel structures in China. Only chemical, electrical and smelting equipment use seamless or alloy steel pipes. Therefore, the use of welded pipe is very extensive, welded pipe has a large market. For welded pipe, it is only square pipe and circular pipe. Square pipe has the advantages of short welding length and high pressure, and has transcendence in some specific aspects. The advantages of the tube. For circular pipe, the price is low, the production caliber is large, and the stock is large, which has always occupied half of the welded pipe industry.


Square and circular pipes are used in a relatively large number of pipes in the construction industry, but there are advantages and disadvantages in both applications.
The use of square rectangular pipe as building column is better than that of round steel.
2. In corners, square tubes can be used to maximize the effective use of building areas.