Steel pipe non-standard shapes can be divided into ellipticalSpecial Section Steel PipeTriangle-shaped special steel tubes, hexagonal special steel tubes, rhombus-shaped special steel tubes, octagonal special steel tubes, half-circular special steel round tubes, unequal edge hexagonal special steel tubes, five-petal plum blossom-shaped special steel tubes, double-convex special steel tubes, double-concave special steel tubes, melon-shaped special steel tubes, conical special steel tubes, wavy special steel tubes.