Seamless pipe made of a single piece of metal with no seams on the surface is called a seamless steel pipe. According to the production method, the seamless pipe is divided into a hot rolled pipe, a cold rolled pipe, a cold drawn pipe, an extruded pipe, a top pipe, and the like. According to the shape of the section, the seamless steel pipe is divided into two types: a circular shape and an irregular shape, and the shaped pipe has a square shape, an elliptical shape and the like. The maximum diameter is 650mm and the minimum diameter is 0.3mm. Seamless steel pipe is mainly used as petroleum geological drilling pipe, cracking pipe for petrochemical industry, boiler pipe, bearing pipe and high-precision structural steel pipe for automobile, tractor and aviation.