1, Material problems. The degree of deformation of different materials after stamping is different. The greater the degree of deformation of stainless steel, the harder it is to level. This is because of the rigidity of stainless steel, so the flattening in the later stage is difficult to achieve the same flatness as before. 

　　2, Aperture, hole spacing problem. The smaller the hole is, the denser the pitch is, the worse the flatness is. The punching process of the punching needle and the stainless steel rod when the 420 stainless steel rod is pressed is equivalent to annealing the stainless steel rod, so the stainless steel rod is not well leveled.

　　3, Leaving the edge of the board. The bigger the margin, the worse the flatness is. The opening ratio is larger, the aperture is larger, and the four sides are whiter. It is not easy to level, but we have leveling equipment, and we will level the 420 stainless steel rod as much as possible. Convenient for customers.