Colby fastener question.

Mark Barone

Mark Barone

Well-Known Member
I have never used them but hope to soon. Are they difficult to use? What are the basic steps. I am assuming I would have to make sure the handle width is very specific to the bolt. Or are they adjustable to different widths?
 
Good video that shows how a corby works. I would not grind down the corby to fit the hole but would drill a slightly larger hole instead.
Adjusting the length is simply grinding down some of the inside mating threads and hole and usually you don't have to do that. You do want to test the length of fit before gluing up to make sure the threads don't bottom out.

I would also add some epoxy to the threads.
Corby bolts provide a mechanical lock and are a more robust method of holding scales on.

Retroguy said:
NM I found this video. Would you add anything?
Click to expand...
 
Do you do any additional clamping while the glue sets up? Are there certain applications where you would choose or recommend to use Corby bolts over straight pins or vice versa? Is it just personal preference?
 
I use corbys almost exclusively

The video is very good but I agree with the Boss. Don't grind down the diameter, just open the hole up a bit.

Also, adjust the corby to your handle width not your handle to the corby.

They are a bit more difficult to use than a straight pin because you have to do some calculations to make everything fit correctly.

This is what happens when you miscalculate the depth and grind through the head.

le6u5YAl.jpg
 
I'm beginning to understand. I did want the Colby to be reset so I would see the head. I like that look.
 
Retroguy said:
I'm beginning to understand. I did want the Colby to be reset so I would see the head. I like that look.
Click to expand...
If you mean you want to keep the slot in the heads for the look of a screw head, it looks like you would have to have fairly thick handle scales. I wonder if you could deepen the slot a little so you can thin the scales and keep the slot effect...?
 
Motor City Mike said:
I use corbys almost exclusively

The video is very good but I agree with the Boss. Don't grind down the diameter, just open the hole up a bit.

Also, adjust the corby to your handle width not your handle to the corby.

They are a bit more difficult to use than a straight pin because you have to do some calculations to make everything fit correctly.

This is what happens when you miscalculate the depth and grind through the head.

le6u5YAl.jpg
Click to expand...

This is almost exactly what happened on a knife I was working on this week, which I'm now calling defunct.

I wish I'd seen this video before I started using the corby's and also the other comments here.

Question though. I ground in a tapered tang which I think added to the problems I was having. Is it advisable to use corby's with a tapered tang or should I just use some pins? The knife I'm working on I want to be both strong and light. Thus the corby's and a tapered tang
 
Sean Jones said:
This is almost exactly what happened on a knife I was working on this week, which I'm now calling defunct.

I wish I'd seen this video before I started using the corby's and also the other comments here.

Question though. I ground in a tapered tang which I think added to the problems I was having. Is it advisable to use corby's with a tapered tang or should I just use some pins? The knife I'm working on I want to be both strong and light. Thus the corby's and a tapered tang
Click to expand...

I don't think it makes a difference with a tapered tang as long as your holes are drilled before you taper the tang
 
All good advice!! I would add this..... once installed, and you start grinding things down.....HEAT IS YOUR ENEMY!! I've seen countless examples of folks getting in a hurry when grinding handles with corby bolts...... and burning/wrecking the handle material.

Tim made a good point...... Corby bolts were designed for the slots to be ground away....if you wanna leave the slots.....your handle materials is gona have to be WAY thick. ;)
 
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You know, just thinking out loud here...

Why not use a button head screw from each side of the handle with a threaded tube (bushing) in the pin hole the way folders are made? Then you can grind the screws and bushing to whatever length you need rather than the screw head?
 
The last time that I bought Corbys from Jantz they carried counter bore bits for specific sized Corbys and other types of bolts. There was no need to slowly grind the sides of the bolts down to fit.

Doug
 
So what are these? Are these Corbys. Are Chicago bolts the same thing. I actually thought no epoxy was used so you could change handles. Not my knife!!IMG_4105.JPG
 
Those are black oxide allen head bolts.....likely with an internally threaded sleeve...... not something you would see an experienced maker use.
 
Personally I have never used a Corby but did make something similar for some of the first knives I made. I used a homemade version of a sleeve and threaded screws. Kind of Corby-ish or not! Back then I was in the winging it mode. Never knew there were knife forums where you could learn or solicit advice or places where you could buy materials for knives!! Everything I was using was on the home-made plain!!

Ed is so right, heat is your enemy. If you let that get too hot you will end up with a ring around it. And no matter how you sand will you ever get rid of it! It is where the wood around it charred!

The first knife I was just speaking of I use a homemade threaded sleeve and two brass thick headed screws. I made a pocket for the head to set down into and then proceeded to grind off the head down flush too the wood. Before I knew what had happened a ring around the screw head began to appear!
After I had ground the head down and final shaped the handle. I tried everything to get rid of the ring! I hand sanded and hand sanded and the only thing I ever accomplished was to lighten the ring. Never could get rid of it. That was a lesson learned that I have not forgotten. Even with pins only I watch for the heat, dunk often, or if you have to or stop often but even with antler and bone you can heat the area around the pin or Corby and once that ring appears you are done and not in a way you want to be done!! It is actually easier to burn the bone or antler. The heat effects it quicker!

Another thing as you are assembling with a Corby or a sleeve w/screws, you need to run some epoxy on the threads. Boss mentioned something about it!! One of my first knives was returned with the homemade screw and sleeve thing! One of the screws had started to back out and caused the handle to loosen. Now your faced with having to re-do and try and sand down and not get into the handle material itself. The odds of doing that are slim and none. I ended up having to totally re-handle the knife, at my cost! So now I slather them down with epoxy at assembly. Then watch the heat so as not to cook it out of there!!
 
TimGinMN said:
Do you do any additional clamping while the glue sets up? Are there certain applications where you would choose or recommend to use Corby bolts over straight pins or vice versa? Is it just personal preference?
Click to expand...

You don’t need to any extra clamps when gluing with Corbys but there is a pathological need to clamp also. It won’t hurt unless you squeeze all the epoxy out. I don’t use clamps with Corbys.
 
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