Corby/loveless holes shrinking…

t1mpani

t1mpani

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So, after my rosewood scale split in half from the 5/16” Loveless screws going into holes that had been drilled with a 5/16” rivet drill AND reamed with a 5/16” reamer; and I just barely overcame the desire to go on a ball-peen hammer smashing spree….I recalled that at some point one of the many hardware supply places was offering either drills that were oversized or maybe it was fasteners that were undersized. Like instead of .310 their bolts (may have been corby) were like .305 or something, so that when the newly drilled holes in the handle material invariably shrink when the drill comes out, the bolts go in just fine. It’s been so long since I bought hardware, I can’t remember who that was—-is it ringing a bell for anyone?
 
Is this rosewood stabilized or no?
Are you certain it's dried enough. How long did it take to crack after being made?

Sucks that it happened to you, sorry.
 
Oh it’s been sitting around for 7-8 years. Most of my customers want G10, so I don’t get to use my hardwoods much. I’ll get over it, but it’s just annoying that the specialized bits that Jantz, etc make don’t actually drill the holes large enough for the hardware to just go in—makes me wonder if they’ve ever tried using them. I’ve run into this with synthetic materials too, where I have to turn the bolts down in order to fit. I just ordered a size O bit (0.316”) that I’ll make into a stepped bit just for this purpose. Just wish I could buy a few hundred sets of slightly undersized loveless bolts. 😁
 
Ed Caffrey mentions in a thread on another forum from 2018 that the bits sent with bolts are the same diameter and need to be drilled a few thousands larger.
 
Not sure what a "rivet drill" is, but if you have a 5/16" Corby bolt or Loveless nut, the hole needs to be 17/64".
More important, the seat needs to be flat shouldered, or the stress of the bolt/nut being tightened will cause stress leading to a crack.

To properly install Corby bolts or Loveless Bolts you need a counterbore that is sized to fit the fastener you choose. Even different manufacturers have slightly different size bolts. Get the counterbore from the same supplier you get your bolts from.
 
Just so we are clear. .... Your bore cracking from the hardware happened quickly?

Not like 3-6 months after made.


Here, I've been bummed that my CT'BORES seemed too Big....just the opposite of your issue.
*But I make Mine
 
Last edited:
Stacy E. Apelt - Bladesmith said:
Not sure what a "rivet drill" is, but if you have a 5/16" Corby bolt or Loveless nut, the hole needs to be 17/64".
More important, the seat needs to be flat shouldered, or the stress of the bolt/nut being tightened will cause stress leading to a crack.

To properly install Corby bolts or Loveless Bolts you need a counterbore that is sized to fit the fastener you choose. Even different manufacturers have slightly different size bolts. Get the counterbore from the same supplier you get your bolts from.
Click to expand...


A tapered bottom sounds like it could definitely change the clamping forces and split. Good call
 
No, happened immediately for me. This is a rivet drill, Jantz sells them. Sounds like my method will be best, I’ll just make a larger bit. The ones I had worked for YEARS with my old hardware that I bought in bulk at Blade Show. Oh well, life goes on. I see fasteners coming from Amazon that have 8mm and 6mm choices, I’m wondering if (even though I bought them from Trace) we’re getting metric stuff now.
 

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Your drills may be worn. Before I switched to carbide couterbores I would only get a hundred or so holes at most before the bolts wouldn't go in anymore.
 
It *is* possible to make your own counterbores. Even though I got yelled at here for posting about it, by doing so you can select the appropriate drill bit to suit your corbys. A google search will reveal several videos about this. IIRC, Walter sorells has a really instructive piece on this…
 
I use the step drills from Jantz made from brad point drill bits, they work well, only issue I have is that I typically have to ream the hole to accept the .250" head corby bolts.
 
I'd go with the worn theory. I don't use them a whole bunch but I have worn out one of the bits shown above and the Loveless Bolts wasn't fitting. Already had a different one in the same size and it worked fine. Just finished up this set of steak knives in rosewood with Loveless bolts yesterday.

oZChouv.jpg
 
Warren
i have always made my own counterbores.. i have never gotten any from anywhere that are exact size.
even the piloted ones vary quite a bit
making them is just another task taking about 15 minutes.. if you p.m me ill share a great secret on how to make them...
 
Pinoy Knife said:
Warren
i have always made my own counterbores.. i have never gotten any from anywhere that are exact size.
even the piloted ones vary quite a bit
making them is just another task taking about 15 minutes.. if you p.m me ill share a great secret on how to make them...
Click to expand...
No secrets..... ;P
 
If you buy your counterbore from the company that sells your quality, USA made, corbys then it is an exact fit as Stacy has already pointed out. I have now dealt with 2 companies for corbys and both those companies counterbores worked perfectly with their corbys.
 
Pinoy Knife said:
Warren
i have always made my own counterbores.. i have never gotten any from anywhere that are exact size.
even the piloted ones vary quite a bit
making them is just another task taking about 15 minutes.. if you p.m me ill share a great secret on how to make them...
Click to expand...
Hello Matt! I don’t seem to be able to PM you—I’ll take a look and see if I can find your email address. My old warhorse computer died and had all that stuff on it. :)
 
I also just ordered a “Chicago screw step bit” at 8mm/4mm, which oughta be about 0.003” bigger all way around.
 
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