(1) Simple cross-section steel pipe-round steel pipe, square steel pipe, oval steel pipe, triangular steel pipe, hexagonal steel pipe, diamond steel pipe, octagonal steel pipe, semi-circular steel circle, and others.
(2) Complex cross-section steel pipes-unequal hexagonal steel pipes, five-lobed plum steel pipes, double convex steel pipes, double concave steel pipes, melon-shaped steel pipes, conical steel pipes, corrugated steel pipes, case steel pipes, and others
