The Max Force Head Chamfer on shoulder punches made by American Punch Company provide important benefits.
The contact head chamfer is increased, which decreases the head diameter, reducing the compressive loading and flex on the unsupported outside diameter of the head during impact.
Improved Fit
American Punch shoulder punches are also equipped with bodies that are oversized +.0002/+.0005, enabling a slight press fit into the retainer. This decreases the likelihood of an improper fit, which is one of the main causes of breaking punch heads. The fit can also be improved through good container design, along with proper build and assembly practices.
Another cause of punch head breakage is high forces caused by impact or snap-through. Impact failure usually occurs because of excessive loading, due to an unreasonably hard or thick workpiece or by insufficient cutting clearance with the mating die. Snap-through failure often happens when stamping higher-strength materials with excessive die clearance. It results from the sudden unloading of pressure when the material fractures.
Force Distribution
In both these types of failures, the punching force is distributed through the punch body and then concentrates at the head. A hardened backup plate is often specified for these tough applications. A good alternate solution is using American Punch’s headed punches, featuring the Max Force Head Chamfer.
The Assistance You Need
Not sure why your punch heads are breaking? American Punch can help solve the mystery. Send them the broken punch, along with a sample of the material being punched, and they’ll provide recommendations specifically for your application.
American Punch is a font of helpful information for your everyday – and extraordinary – punching applications. Its website includes:
- A fraction to decimal and millimeter conversion chart
- A punching calculator
- Standard punch set-up recommendations
- Safety tips for using punches and dies
Contact American Punch today to learn how it can meet your precision tooling needs.
