1. Classification by production method
(1) Seamless pipe - hot rolled pipe, cold rolled pipe, cold drawn pipe, extruded pipe, pipe jacking;

(2) Welded pipe: arc welded pipe, resistance welded pipe (high-frequency, low-frequency), gas welded pipe, furnace welded pipe; Classified by weld seam - straight seam welded pipe, spiral welded pipe
 

2. Classification by section shape
(1) Simple section - round, square, rectangular, elliptical, triangular, hexagonal, rhombic, octagonal, semicircular;

(2) The complex section is an unequal hexagon, five petal plum blossom, biconvex, biconcave, melon seed, cone and ripple;

(3) According to the wall thickness, it can be divided into a thin wall stainless steel pipe and a thick wall stainless steel pipe;