By manufacturing process classification

The manufacturing processes of seamless steel pipes can be divided into the basic categories: hot rolling (extrusion), cold rolling (drawing), and hot expanded pipes.

(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.

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 other non-standard steel pipes such as complex cross-section pipes, double concave pipes, five-petal plum blossom-shaped pipes, conical pipes, corrugated pipes, melon-shaped pipes, double convex pipes, etc.

Categorized by Application

Steel pipes are categorized by their applications, including pipeline steel pipes, heat exchanger steel pipes, machinery industry steel pipes, oil and geological drilling steel pipes, container steel pipes, chemical industry steel pipes, and steel pipes for special purposes.