Drilling Stepped holes

J. Hoffman

J. Hoffman

Knifemaker / Craftsman / Service Provider
Joined
Jan 1, 2011
Messages
1,776
When I'm using Corbys or Loveless screws on my handles I mark the position for the holes, and drill the smaller hole all the way through the handle material. I do this separately for each scale. Then I drill out the larger holes, about half way through the scale. The problem I'm having is centering the larger hole over the smaller hole. I've tried putting the larger bit into the hole to center it, but it doesn't work? Should I be drilling the larger hole first, and then drilling the smaller one? What I have done to this point when this happens is take a chainsaw file and slightly enlarge the smaller hole so the bolts fit. I don't like doing this because I think it could weaken the holding power of the bolts. If photos would help, I can take some. Thanks in advance.
Jess
 
Thanks Mike, I'll see if I can find those. They sound perfect.
Jess
 
You can also buy stepped drill bits from most suppliers that sell corby and lovelace bolts.

- Chris
 
Pop's counterbores and bolts are great. He makes the bolts to fit the counterbore. It helps to get them both from the same place wherever you get the bolts.
 
I also use Pop's counterbores with his corbys and they work great.

You should buy the right tool for the job, but if money is tight you can clamp your work, drill with one size bit, change bits, then drill with the other size. That's the only way to make sure you're on center but it's slow.
 
This is all great advice, and Pop's is great when it comes to customer service.:thumbup:

Just to add though, if you find yourself drilling holes for a corby or Loveless bolt and you do not have a counterbore of step drill on hand, the best advice I can give you is to drill both holes at the same time without un-clamping the workpiece.

If I were drilling a hole for a corby bolt, I would put the scale material on the drill press table, line up the bit with my mark for the hole and clamp the scale material to the table. Next, I'd drill the 3/16" hole and then would change to the 1/4" bit for the shoulders and drill to the desired depth without ever un-clamping. That way you don't have to worry about having the larger hole uncentered.

Hope this helps.
 
LOL, my bad....

Posted my response before I read fumbler's answer. He said it perfectly:thumbup:
 
Yep, always larger then smaller so the hole on the surface is tight and the clamped drill press switch over should turn out perfect if you only have straight bits. When you start small and go larger, un-clamped work will wobble until the bit bites in, not a clean look with a round shape in an oval hole.
Also, best bit for the 1/4" is a forstner, clean perimeter and flat bottom
 
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Sorry beretta96man but I disagree with you. The best option I have seen is the counterbore thing where the small hole is drilled first and if no counter bits are used, I have found that for all materials except mammoth tooth, drilling the small hole first is still the best way to go. Certainly extra care can be needed to use a sharp bit for the larger hole. Frank
 
Thanks for all the great info. I agree with Pops service, and I get all my belts from him. I've never used his corbys though. I think I'm going to go with the counterbore system. It looks like the counterbore will leave a nice square shoulder for the bolts, Once again, I'm glad I asked for help from the pros.
:)
Jess
 
Jess, there was one size corby bolt that I had to modify the pilot because MSC didn't carry the size I needed. I use my counterbores for more than just corbys, like countersunk finials. So those CB's that pops sells look a great tool, just not interchangeable.
 
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