CNC turret punching machine tool Factors affecting die wear

In terms of wear, punches usually wear out faster than dies, and the specific lower die punch core is less affected by the aforementioned factors. High stamping speeds can generate excessive friction heat, which reduces the hardness of the punch core and accelerates wear. The shear surface of the punch core, which absorbs the initial impact, typically wears out the fastest. Withdrawal conditions also affect wear; using uniform force to withdraw the punch core from the workpiece facilitates smoother material withdrawal.

The material of the mold is crucial; high-speed steel (HSS) undergoes several heat treatments to enhance the toughness and hardness needed for long-lasting molds. Punch cores that are double heat treated can achieve a Rockwell hardness of HRC62. Hardened tool steel with a Rockwell C hardness of 59 is ideal for dies as it provides a balance between maximum edge wear resistance and breakage prevention.

Finally, the performance of the workpiece, including its physical and mechanical properties, significantly impacts the die's lifespan. Thicker workpiece materials cause the punch core to wear out faster.