The blanking clearance of precision metal stamping parts refers to the gap between the punch and the die in blanking. The blanking clearance of precision metal stamping parts has a great influence on the blanking process. In addition, clearance pressure and die life also have a greater impact. When the gap is very small, the extrusion and friction effect of the material is enhanced, and the blanking force is bound to increase. It will cause fracture separation, so it will reduce the blanking force.
Precision metal stamping parts blanking clearance to determine we take a reasonable clearance, the reasonable clearance has a maximum and minimum value. In the design and manufacture of molds it is usual to take the smallest reasonable clearance. There are two ways to determine a reasonable gap.
The blanking gap of precision metal stamping parts has an impact on the life of the die. The life of the die is expressed by the number of qualified blanking parts before the die failure. There are many forms of failure, and the common forms of failure are wear deformation and die swelling and cracking. The size of clearance has a great effect on the wear of die and the crack of die. After the die edge is worn, the edge will be passivated and the clearance will increase, which will lead to the reduction of the dimensional accuracy of the parts and the roughness of the section. The passivation of the edge will make the crack point move from the edge end to the side, resulting in burrs, which are generated in the parts, so it is necessary to pay attention to reduce the wear of the die as much as possible.
