Shanghai large-diameter low-alloy square tube 450 * 450 * 12-14 Shanghai Iron Horse Industry Co., Ltd. supply low-alloy square tube, low-alloy rectangular tube, Q345B square tube, Q345B rectangular pipe, galvanized pipe, galvanized rectangular tube, shaped size of square tube production order. Low-alloy square tube 400 * 400 * 8.0 low-alloy square tube 400 * 400 * 10.0 low-alloy square tube 400 * 400 * 12.0 low-alloy square tube 400 * 400 * 14.0 low-alloy square tube 400 * 400 * 16.0 low-alloy square tube 400 * 400 * 20.0 low-alloy square tube 450 * 450 * 12.0 low-alloy square tube 450 * 450 * 14.0 low-alloy square tube 450 * 450 * 16.0 low-alloy square tube 500 * 500 * 16.0 low-alloy square tube 500 * 500 * 20.0 Low alloy square tube 600 * 600 * 16.0 low-alloy square tube 600 * 600 * 18.0 low-alloy square tube 600 * 600 * 20.0 low alloy rectangular tube 300 * 400 * 10.0 low alloy rectangular tube 300 * 400 * 12.0 * 300 low-alloy rectangular tube 400 * 14.0 low alloy rectangular tube 300 * 400 * 16.0 low alloy rectangular tube 300 * 500 * 16.0 low alloy rectangular tube 300 * 500 * 18.0 low alloy rectangular tube 300 * 600 * 12.0 low alloy rectangular tube 400 * 500 * 12.0