Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Aug 20, 2004
- Messages
- 37,925
When I have needed to make a quick counterbore for a recessed hole in a scale or other project, I chuck the desired size stub length drill bit in a cordless drill and grind the step down on a disc grinder or against a coarse diamond stone. It can be done on a lathe or drill press, too.
Try to get the step even and at a perfect right angle. The pilot should be the exact size of the bolt shank. Once done, I grind the newly created shoulder edge at an angle with a small diamond disc in a flex shaft/Dremel tool/die grinder. This creates a sharp cutting edge to make clean seats. You might say the cutting part is sort of like a tiny Forstner bit.
To use this counterbore, I first drill the pilot hole for the shank and then use the counterbore to cut the seat.
You can do a similar counterbore by turning down a spade drill, too. You have to sharpen the new cutting edges you created. Be sure to leave the spur tip or it won't bore smooth holes.
Try to get the step even and at a perfect right angle. The pilot should be the exact size of the bolt shank. Once done, I grind the newly created shoulder edge at an angle with a small diamond disc in a flex shaft/Dremel tool/die grinder. This creates a sharp cutting edge to make clean seats. You might say the cutting part is sort of like a tiny Forstner bit.
To use this counterbore, I first drill the pilot hole for the shank and then use the counterbore to cut the seat.
You can do a similar counterbore by turning down a spade drill, too. You have to sharpen the new cutting edges you created. Be sure to leave the spur tip or it won't bore smooth holes.
