1, according to the production method can be divided into two categories: seamless steel pipe and seamed steel pipe, seamed steel pipe referred to as straight seam steel pipe.

2、Steel pipe can be divided into two categories according to the material: carbon pipe and alloy pipe, stainless steel pipe.

3、Steel pipe can be divided into: light pipe and wire pipe according to the way of pipe end connection.

4、Steel pipe can be divided into: black pipe and coated pipe according to the surface coating characteristics.

5、Steel pipe can be divided into: round steel pipe and shaped steel pipe according to the shape of cross-section.

6, commonly used welded steel pipe can be divided into: high-frequency welded pipe, straight seam submerged arc welded pipe, spiral submerged arc welded pipe.

Seamless steel pipe: seamless steel pipe wall thickness is thicker, diameter thickness is smaller. However, the diameter of the pipe is limited, its application is also limited, and the production cost, especially the production cost of large diameter seamless steel pipe is relatively high.

High-frequency welded steel pipe: high-frequency welded pipe pipe shape is good, uniform wall thickness, welding produced by the internal and external burrs through the corresponding tool to scrape, on-line through non-destructive testing to strictly control the quality of the weld seam, the degree of automation is very high, the production cost is low. But the wall thickness is relatively thin, the pipe diameter is relatively small, the wall thickness is generally not more than 12mm, the diameter of the pipe is generally not more than 610mm, the steel structure is particularly suitable for the production of pipe diffuser frame structure.