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 according to manufacturing processes: straight seam welded steel pipes, spiral welded steel pipes, plate-and-roll butt-welded steel pipes, and hot-expanded welded pipes.

By Shape Classification

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-petaled plum-shaped pipes, conical pipes, corrugated pipes, melon-shaped pipes, and double convex pipes, etc.

Categorized by Use

Steel pipes are categorized by their applications, including 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 steel pipes for special purposes.