The closed iron barrel will be flanged, corrugated, ribbed and crimped after the barrel body is welded. The thickness of the barrel body welded without edging is twice the normal thickness at the weld. The uneven thickness of the barrel body will affect the quality of the subsequent process, especially when hemming and sealing. It makes a lot of material piled up at the welding seam, which cannot meet the requirements of normal curling. This area is called the seam triangle, and it's an eventful area. Since there are more materials than other hemming parts, it is difficult to adapt to the groove shape of the hemming roller, so iron tongues often appear, gaps appear on both sides of the seam welding, and leakage in the triangle area occurs. This is the most serious problem with the quality of iron drums. Therefore, in order to obtain a thickness similar to that of other parts at the welding seam, edging is the most direct method, because the thickness of the welding seam is thinner than that of other parts through edging at the overlapping edge of the welding seam. , the thickness of the weld will be significantly reduced. Therefore, in order to obtain a thickness similar to that of other parts at the welded seam, edging is the most direct method, because the thickness of the welded seam is thinner than that of other parts through edging. After that, the thickness of the weld will be significantly reduced.