Seamless steel tube is a steel pipe that is perforated from the entire round steel and has no welds on the surface, which is called seamless steel tube. According to production methods, seamless steel pipes can be divided into hot-rolled seamless steel pipes, cold-rolled seamless steel tube, cold-drawn seamless steel pipes, extruded seamless steel pipes, top pipes, etc. According to the cross-sectional shape, seamless steel tube are divided into two types: circular and irregular. The irregular pipes have various complex shapes such as square, elliptical, triangular, hexagonal, melon seed, star, and finned pipes. The maximum diameter is 900mm, and the minimum diameter is 4mm. According to different purposes, there are thick walled seamless steel pipes and thin-walled seamless steel pipes. Seamless steel tube are mainly used for petroleum geological drilling pipes, cracking pipes for petrochemical industry, boiler pipes, bearing pipes, and high-precision structural steel pipes for automobiles, tractors, and aviation
Seamless pipes for structural purposes (GB/T8162-1999) are seamless pipes used for general structures and mechanical structures. It is a variety of seamless steel pipes classified according to their different uses.
Application field of seamless pipes for structural purposes
Stainless steel seamless pipes for structural purposes (GB/T14975-2002) are hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless pipes made of stainless steel, which are widely used in industries such as chemical, petroleum, light textile, medical, food, machinery, and other corrosion-resistant pipelines and structural components.
GB/T8162-1999 (Seamless Pipe for Structural Purposes) is mainly used for general structures and mechanical structures. Its representative material (grade): carbon steel 20, 45 steel; Alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.
Executive standard for seamless pipes for structural purposes
Seamless steel tube for structural purposes: GB8162-99
Seamless steel tube for fluid transportation: GB8163-99
Seamless steel tube for boilers: GB3087-1999
High pressure seamless tube for boilers: GB5310-95 (ST45.8- type III)
High pressure seamless steel tube for fertilizer equipment: GB6479-1999
Seamless steel tube for geological drilling: YB235-70
Seamless steel tube for oil drilling: YB528-65
Seamless steel tube for petroleum cracking: GB9948-88
Seamless pipe for petroleum drill collars: YB691-70
Seamless steel tube for automotive axle shafts: GB3088-1999
Seamless steel tube for ships: GB5312-1999
Cold drawn and cold-rolled precision seamless steel pipes: GB3639-1999
Various alloy tube 16Mn, 27SiMn, 15CrMo, 35CrMo, 12CrMov, 20G, 40Cr, 12Cr1MoV, 15CrMo