According to GB2102-88. There are three types of steel pipe packaging: bundling, packing, oiling or oiling. A steel pipe is a long strip of steel having a hollow section and no seams around it. Steel pipes have a hollow section and are used in large quantities as pipes for transporting fluids, such as pipes for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, the steel pipe is lighter in weight when it has the same bending and torsional strength. It is an economical section steel and is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycles. Shelf and steel scaffolding used in construction. The use of steel pipes to manufacture ring-shaped parts can improve material utilization, simplify manufacturing processes, save materials and processing man-hours, such as rolling bearing rings, jack sleeves, etc., and have been widely used in steel pipes. Steel pipes are also indispensable materials for various conventional weapons, and barrels, barrels, etc. are all made of steel pipes. Steel pipes can be divided into round pipes and shaped pipes according to the shape of the cross-sectional area. Since the area of the circle is the largest under the condition of equal circumference, more fluid can be transported by the circular tube. In addition, the circular section is subjected to a relatively uniform force when subjected to internal or external radial pressure, and therefore, most of the steel pipes are round pipes.

However, the round pipe also has certain limitations. For example, under the condition of being bent by the plane, the round pipe is not as strong as the square and rectangular pipe, and some agricultural machinery skeletons, steel wood furniture, etc. are commonly used square and rectangular pipes.