Cracks often appear when the bending radius and bending angle are too large. For products with small bending width, cracks appear at both ends of the width; When the bending width is large, the crack appears on the bending curve, close to the middle of the bending width. In addition, cracks often appear in the right angle part of the bending curve.

Solutions to cracks in Metal Stamping Parts:
1. When cracks occur during stamping, measures shall be taken.

(1) When the radius of curvature is constant, the thicker the plate or the longer the bending width, the greater the possibility of crack occurrence. When SPCC steel plate is used, if R / T < 0.5, cracks will occur. Therefore, the design with R / T greater than 0.5 can avoid the occurrence of cracks.

(2) Make the bending curve at right angles to the direction of the optical fiber. However, because the bending limit in the fiber direction is different from that in the vertical direction, when the bending limit is close to the ultimate bending, the relationship between the bending curve and the fiber direction should be considered.

(3) The burr side is located on the inner side of the elbow and deburred.

(4) Only the burr part of the stamping curve shall be annealed.

(5) Before stamping, compress the cutting surface on the burr side to a 45 degree angle.

(6) When the bending limit of thick plate is exceeded and it needs to be bent into small R, the additional back pressure method is adopted. In the free bending die, the lower die adopts a strong ejector plate, which increases the compressive stress of the deformed part of the plate in the bending process, so as to greatly reduce the bending radius and prevent the generation of cracks. Form a V-shaped top by bending the outside of the product.
2 measures to be taken when the bending part is at right angles to the bending curve in the processing of stamping parts.
(1) If the curve moves backward from the blank end face (2t + R), or the bending curve is aligned with the blank end face, an empty groove (1.5-2.0t + R) needs to be made.

(2) When hollow bending is carried out, a groove larger than 2-3 times the plate thickness must be punched out first, and then bending, or a circular process hole must be opened in the previous process, and then stamping (cutting) - bending processing must be carried out.