During the stamping process, the side wall near the fillet of the female die is thickened, and the side wall near the fillet of the male die is thinned (serious necking or even cracking). This is a normal phenomenon and it must exist. It is impossible to completely eliminate it. The control of its thickening and thinning degree comes from the following aspects:

I. Process design stage:

1. Analyze and verify the fillet radius r of punch and die.

2. Change the shape of the supplementary part of the process or the shape of the pressing surface, and change the shape of part of the product if possible, so as to achieve better production manufacturability.

The above two items need a lot of practical experience or CAE analysis to check the thickening and thinning degree of each part as a reference for improvement.

Second, the production stage:

1, adjust the process parameters such as BHF (experiment).

2. Improve the surface roughness and lubrication conditions of the die.

3. The R angle of the punch should be repaired according to the actual situation.

4. Change the plate size or die positioning, even the drawing grade of the material brand, in order to obtain better forming effect.