Seamless steel pipes are钢管 made by piercing a solid round steel billet, featuring no welds on the surface and are known as seamless steel pipes. According to the production method, seamless steel pipes can be categorized into hot-rolled, cold-rolled, cold drawn, extruded, and jacking types. In terms of cross-sectional shape, they are divided into circular and non-circular pipes. Non-circular pipes come in various shapes such as square, elliptical, triangular, hexagonal, pumpkin, star-shaped, and winged pipes. The diameter can reach 900mm, with the minimum diameter being 4mm. Depending on the application, there are thick-walled and thin-walled seamless steel pipes. Seamless steel pipes are primarily used for oil and gas geological drilling pipes, cracking pipes for petrochemical use, boiler pipes, bearing pipes, and structural steel pipes for automobiles, tractors, and aviation.