Difference between rectangular pipe and rectangular steel pipe:

Rectangular tube is a kind of hollow long steel, also called flat tube, flat square tube or square flat tube (literally). A large number of pipelines used for escorting fluids, such as oil

Natural gas, water, gas, steam, etc. In addition, when the bending and torsional strength are the same, the weight is lighter, so it is also widely used to manufacture mechanical parts and engineering structures. It is also used for consumption of various conventional weapons.

Classification of rectangular pipes: steel pipes are divided into seamless steel pipes and welded steel pipes (seamless pipes), hot rolled Seamless square tube Cold drawn seamless square tube, extruded seamless square tube, welded square tube. 　

The welded square pipe is divided into:

(a) According to the process - arc welding square tube, resistance welding square tube (high-frequency, low-frequency), gas welding square tube, furnace welding square tube (b) according to the weld seam - straight seam welding square tube, spiral welding square tube.