Seamless steel pipes are made by piercing a solid round steel billet, resulting in pipes without any welds on the surface. Depending on the production method, seamless steel pipes can be categorized into...Hot-rolled Seamless Steel Pipe、Cold-rolled seamless steel tubes、Cold Drawn Seamless Steel PipeExtruded seamless steel tubes, jacking pipes, etc. Seamless steel tubes are divided into round and non-round shapes based on cross-sectional shape. Non-round tubes include square, elliptical, triangular, hexagonal, melon-shaped, star-shaped, and winged tube, among other complex shapes.