Seamless steel pipe is a long strip of steel with hollow section and no joint around it. Steel pipe has hollow section and is widely used as pipeline for conveying fluid, such as pipeline for conveying oil, gas, gas, water and some solid materials. Compared with solid steel such as round steel, steel pipe has the same bending and torsional strength and light weight. It is an economic section steel. It is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and steel scaffold used in construction.

Manufacturing ring parts with steel pipes can improve material utilization, simplify manufacturing processes, and save materials and processing hours, such as rolling bearing rings, Jack sleeves, etc. at present, steel pipes have been widely used for manufacturing. Steel pipe is also the material of various conventional weapons. Gun barrel and barrel should be made of steel pipe. Steel pipe can be divided into round pipe and special-shaped pipe according to different cross-sectional area and shape. Because the circular area is large under the condition of equal circumference, more fluid can be transported with a circular pipe. In addition, when the ring section is subjected to internal or external radial pressure, the force is more uniform. Therefore, most steel pipes are round pipes.

However, circular pipes also have limitations. For example, under the condition of plane bending, circular pipes are not as strong as square and rectangular pipes. Square and rectangular pipes are commonly used in the framework of some agricultural machines and tools and steel and wood furniture. Special shaped steel pipes with other section shapes are also required according to different purposes.


1. Seamless steel pipe for structure (GB / T8162-1999) is a seamless steel pipe for general structure and mechanical structure.

2. Seamless steel pipe for fluid transportation (GB / T8163-1999) is a general seamless steel pipe used to transport water, oil, gas and other fluids.

3. Seamless steel pipe for low and medium pressure boiler (GB3087-1999) is a carbon structural steel hot-rolled and cold drawn (rolled) seamless steel pipe used to manufacture superheated steam pipe, boiling water pipe for low and medium pressure boiler and superheated steam pipe, large smoke pipe, small smoke pipe and arch brick pipe for locomotive boiler.

4. Seamless steel pipe for high pressure boiler (GB5310-1995) is a kind of carbon steel, alloy steel and stainless heat-resistant steel seamless steel pipe used to manufacture the heating surface of water tube boiler with high pressure and above.