Classification by production method
(1) According to process - arc welded pipe, resistance welded pipe (high frequency, low frequency), gas welded pipe, furnace welded pipe
(2) According to welding seam - straight seam welded pipe, spiral welded pipe
Classification by cross-sectional shape
(1) Simple cross-section steel pipes - round steel pipes, square steel pipes, oval steel pipes, triangular steel pipes, hexagonal steel pipes, rhombus steel pipes, octagonal steel pipes, semi-circular steel pipes, others
(2) Complex cross-section steel pipes - unequal hexagonal steel pipes, five-petal plum blossom-shaped steel pipes, double-convex steel pipes, double-concave steel pipes, melon-shaped steel pipes, conical steel pipes, corrugated steel pipes, watch case steel pipes, and others
Classified by wall thickness
Thin-walled steel pipe, thick-walled steel pipe
Classification by end shape
Divided into round welded pipes and special-shaped (square, flat, etc.) welded pipes.
