|
|
|
Punch |
The Punch's cutting edge is shaped on a grinder using a drill (the preferred way), or on a metal lathe.
Edge angle on a center punch The center punch is used to mark the position for drilling (particularly on metal), helping to prevent the drill bit from drifting. |
Edge angle on a prick punch The prick punch is used to mark positions by hand for work. Generally a hammer is not used, or is only lightly used. |
|
I will give you an A+ in this class if you SWEAR to me that you will NEVER take this class again. Unknown Shop Teacher |
|
General Guidelines |
||
|---|---|---|
|
Punch Type |
β |
Comments |
| Center | 90° | |
| Prick | 60° | I have seen recommendations for angles as low as 30°, but that makes for a point that will be easily dulled when using with metal. Such an angle might work well if using this with wood though. |
If grinding this on a high speed grinder, be sure to manage the temperature so that the temper is not lost due to overheating. If there is a carbide insert, DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks. Otherwise, cool by dipping as needed in water.
