By manufacturing process classification
Manufacturing processes for seamless steel tubes can be categorized into the basic types: hot rolling (extrusion), cold rolling (drawing), and hot expanded tubes.
(2) Welded pipes can be categorized by manufacturing process into: straight seam welded pipes, spiral seam welded pipes, plate-and-coil butt-welded pipes, and hot-expanded welded pipes.
Categorized by shape
Steel pipes can be categorized by shape into: round pipes, square pipes, rectangular pipes, octagonal pipes, hexagonal pipes, D-shaped pipes, pentagonal pipes, and various other shaped pipes such as complex cross-section pipes, double concave pipes, five-petal plum blossom-shaped pipes, conical pipes, corrugated pipes, melon-shaped pipes, and double convex pipes, etc.
Categorized by usage
Steel pipes can be categorized by application into: pipeline steel pipes, thermal equipment steel pipes, mechanical industry steel pipes, oil and geological drilling steel pipes, container steel pipes, chemical industry steel pipes, and special purpose steel pipes, etc.
