Seamless steel tubes are pipes made from a solid piece of metal with no seams on the surface. They are classified into hot-rolled, cold-rolled, cold drawn, extruded, and jacked pipes based on production methods. According to their cross-sectional shapes, seamless tubes come in circular and non-circular types, with complex shapes including square, elliptical, triangular, hexagonal, pumpkin, star-shaped, and winged pipes. Diameter ranges from 0.3mm to 650mm, and they are divided into thick-walled and thin-walled tubes depending on their applications. Seamless steel tubes are primarily used for oil and gas geological drilling pipes, cracking pipes for petrochemical use, boiler tubes, bearing tubes, and high-precision structural steel tubes for automotive, tractor, and aviation purposes.