What is the problem of curling in the process of making metal stamping parts?

In the process of producing metal stamping parts, manufacturers will have big and small problems, sometimes curling. What are the reasons for this phenomenon? To put it simply; 1. Edge curling occurs due to the uneven surface of the concave die in the metal stamping mold. When the edge of the die is collapsed or notched, the above-mentioned defects will often occur when the die is punched in a recessed state after partial correction. Use the method to improve the surface accuracy of the mold. 2. Due to improper design of the unloading plate in the metal stamping mold, curling occurs. Because the gap between the discharge plate and the punch is too large, curling occurs. The measure is that the discharge plate needs to be close to the punch. In addition, even with this design, if the strength of the unloading plate is weak, the same phenomenon will often occur. 3. When bending and stamping are performed at the same time, curling caused by stretching. When bending and punching are performed at the same time, curling tends to occur due to the hole being stretched into an oval shape. The measures are: either separate the two processes, or pay attention to the simultaneous progress of stamping and bending. 4. When bending, the guide hole is elliptical. Recommended article: How to reasonably determine the stamping direction of deep-drawn stamping parts? Previous post: What are the basic requirements for the design of stamping parts processing technology?