... Round pipe diameter: 89mm-219mm, thickness: 4-30mm 2) Square tube: 16 x 16mm-400 x 400mm, thickness: 4-30mm 3 ... ) Rectangle tube: 19 x 10mm-500 x 300mm, thickness: 4-30mmB: ... , bright and galvanizedC: Length of each pipe: 500mm-16,000mmD: Steel grade: Q195 - Q235A, ST37-2, ST52, S235, S355, SS400, ... For all details, please don't hesitate to contact us. Seamless Tube