Square tube

The utility model discloses a square tube which comprises an inner tube, an outer tube is arranged on the outer wall of the inner tube, supporting plates are fixedly connected to the four corners of the inner wall of the outer tube, and the tail ends of the supporting plates are fixedly connected with the outer wall of the inner tube. According to the square and square tube, the inner tube, the outer tube and the supporting plate are matched, so that the inner tube is protected by the outer tube, the inner tube and the supporting plate are supported by the supporting plate, the connection strength is improved, and due to the design, on one hand, the compression resistance, torsion resistance and bending resistance of the square and square tube are improved, and meanwhile, once the square and square tube is punctured by the outside, the connection strength is improved. The outer pipe can be used for buffering and unloading force, the damage degree of the inner pipe is reduced, the space formed among the suppor