What are the precautions for assembling piercing needles?

When assembling the punching needle, there are mainly the following methods to control the uniform gap between the punch and the die:

1. Light transmission method: place and install the upper die and the lower die, briefly illuminate with a lamp or flashlight, and observe the light transmission in the blanking hole of the lower die.

2. Gasket method: insert the punch into the hole of the concave model corresponding to copper or paper with uniform thickness around the cutting edge of the concave die, and observe the tightness between the punch and the gasket. Tap the fixing plate lightly with a hammer until the tightness of the protrusion and gasket is consistent, and then tighten the upper die after adjustment. In the process of piercing assembly of cemented carbide, it is necessary to ensure that the gap between punch and die is consistent. In order to ensure the uniform gap between punch and die, it is necessary to determine the position of one of them (punch or die) according to the requirements of drawings, and then find the correct gap to determine the exact position of the other workpiece based on this workpiece. Some stamping dies are equipped with multiple cemented carbide punching needles at a time, which requires that the die design is scientific and reasonable.