Seamless steel pipes are made by perforating a whole round steel bar. There is no weld on the surface of the steel pipe, which is called seamless steel pipe. According to the production method, seamless steel pipes can be divided into hot-rolled seamless steel pipes, cold-rolled seamless steel pipes, cold-drawn seamless steel pipes, extruded seamless steel pipes, jacking pipes, etc. According to the cross-sectional shape, seamless steel pipes are divided into round and special-shaped ones. Special-shaped pipes have square, oval, triangle, hexagon, melon seed, star, winged pipes and many other complex shapes. The maximum diameter is 900mm and the minimum diameter is 4mm. According to different uses, there are thick-walled seamless steel pipes and thin-walled seamless steel pipes. Seamless steel pipes are mainly used as petroleum geological drilling pipes, cracking pipes for petrochemicals, boiler pipes, bearing pipes, and high-precision structural steel pipes for automobiles, tractors, and aviation.
