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 welded pipes, plate-and-roll 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 other special-shaped steel pipes, complex cross-section pipes, double concave pipes, five-petaled plum-shaped pipes, conical pipes, corrugated pipes, melon-shaped pipes, double convex pipes, and more.

Categorized by Usage

Steel pipes are categorized by their applications, including: pipeline steel pipes, heat-engine equipment steel pipes, machinery industry steel pipes, oil and geological drilling steel pipes, vessel steel pipes, chemical industry steel pipes, and special-purpose steel pipes.