Dear Somchita
Here is our suggestions regarding to your problem right now:
1. Please do not use hammer or copper rod to knock in the blanking punch into the holder plate. Please use hydraulic press machine to assemble the blanking punch while necessary. Please refer to the photo attached.
2. About 8 years ago, our staff assembled the carbide blanking punches use copper rod and we were facing the same problem you have right now. But after we change the hydraulic press machine, problem solved.
3. This is because if you use copper rod to knock the blanking punch, blanking punch will suffer too much strength from copper rod during assemble into holder plate and blanking punch will broken easily from the most strong part due to the strength.
4. While your engineer visit us in the past, we already demonstrated the assembly method using hydraulic press machine to your team. So please do follow this procedure. Remember, do not use copper rod or hammer!!
5. Another point is, please do not use the same holder plate to assemble the blanking punch for more than one time. The precision may change if you assemble the blanking punch use the same holder plate for more than one time. If necessary, please send back the holder plate with blanking punch to us, we will check for you and replace the blanking punch for you to ensure the precision. Expect for new blanking punch charge, we will not ask for extra exam fee or installation fee.
6. We suggest you to place blanking punches and holder plate as a set while you place a new spare parts order.
If there is any other questions, please feel free to contact me at any time. Thank you!