1、according to production methods classification
（1）seamless pipe - hot-rolled pipes, cold-rolled pipes, cold-drawn tubes, extruded tubes, pipe jacking
（a）in accordance with sub-processes - arc welded pipe, ERW pipe (high frequency, low frequency), gas pipe, furnace pipe
（b）by weld points - Longitudinal Welded Pipe, Spi Welded Pipe
2 in accordance with section shape classification
（1）easy-section steel tube - circular steel tube, square steel pipe, steel tube oval, triangular steel pipe, steel pipe hexagonal, diamond-shaped steel tube, steel pipe octagonal, semi-circular steel, other
（2）the complexity of cross-section steel tube - scalene hexagonal steel pipe, five plum-shaped steel tube, steel tube double-convex, double concave steel pipe, melon-shaped steel tube, conical steel pipe, corrugated-shaped steel tube, steel pipe watchcase, other
3、classified according to wall thickness - thin-walled steel pipe, thick-walle steel pipe
4、by end-use Category - pipe with steel pipe, steel pipe for thermal
equipment, machinery for industrial use steel pipes, petroleum, geological drilling using steel pipe, steel tube container, chemical industrial steel pipes, special-purpose steel pipes, other
