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Categorized by manufacturing process

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-to-roll joint 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, 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 use into: pipeline steel pipes, heat treatment 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.