What would be strongest way to attach knife scales?

J

Josh1992

Joined
Aug 30, 2015
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So I know good epoxy is important to bed the knife scales. Check!
Next is mechanical attachment.

What’s better though?
6- 1/8” peened brass pins, OR 2-3 brass corby bolts? OR something I don’t know about!

Has anyone tested these against each other? I had read that peened pins are stronger because if you do them right you have an hourglass shape inside the handle and it can never come free of the scales?
But I also have heard that Corby bolts are better because of the mushroom shape offering more surface contact?

It seems to me with corby bolts the risk is the threaded part breaking free of the head like when you over tighten a small bolt or machine screw…

And the risk with peening is that it will break in the center where the pin passes through the steel…

When I picture it in my head I would go with pins more redundancy with a greater number of smaller attachments… what do you guys think?
 
Your visualization of peened pins is incorrect. They aren't peened to the point they are an hourglass shape. They are flared on the ends. Peened pins can be flush or raised. Raised heads give you a little more strength.
Peening is something that has to be leaned, and learning requires breaking materials.
Corby bolts or similar are much easier to use and there is no need to tighten them anywhere near the point of breaking.
 
Bill DeShivs said:
Your visualization of peened pins is incorrect. They aren't peened to the point they are an hourglass shape. They are flared on the ends. Peened pins can be flush or raised. Raised heads give you a little more strength.
Peening is something that has to be leaned, and learning requires breaking materials.
Corby bolts or similar are much easier to use and there is no need to tighten them anywhere near the point of breaking.
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I’m not talking about them breaking from over tightening I’m talking about sheer force if the handle gets hit while batoning or chopping. Which is normally why you want strong scale bonding.

I didn’t realize that peening is that easy. This whole time I have been doing it the way a guy on YouTube did. He used a tapered drill after his 1/8 inch drill. Then you leave the top of the pin 1/8 above the material and hammer it down with a ball peen carefully. When I broke the walnut handle with a sledge hammer to see how it came out the pins were indeed hour glass shaped
I didn’t know that this is not normal. Just how I learned.
So with normally done pins 3 corby bolts is probably like having 4 or 5 pins? Because the pin has only a tiny mushroom shape to it?
 
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I made a titanium sword type thing with a two handed handle and I was really worried about the scales peeling off due to the flexibility of the titanium. I used hollow stainless pins, epoxied the scales and pins to the tang, and once the epoxy was cured did all my handle shaping. Once it was shaped, I drilled a 3/8" divot into the pins/scales, tapped the inside of the pins and then epoxied some 12.9 bolts into each one. Lastly, I tied a turk's head at the front of the handle and epoxied that. I did some fairly vigorous testing and had no issues.

In my mind, tight tolerances is a major factor in building a strong handle
 
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If your scales are coming of with either corbies or peened pins, you are doing something with your knife a knife is not made for.
Either is way stronger then needed.

If you want a knife you can drive a tank over use a cord wrap
 
Hengelo_77 said:
If your scales are coming of with either corbies or peened pins, you are doing something with your knife a knife is not made for.
Either is way stronger then needed.

If you want a knife you can drive a tank over use a cord wrap
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That’s a good way to put it. I’m still curious though if you really wanted to put the two to the test which would come out on top? I hope one day to do a test and put it on here, just didn’t want to waste my time by doing something that wastes materials like that without seeing if anyone else has tried it. Maybe one of those knife makers who breaks a knife every batch to see how their design holds up?
 
Stacy E. Apelt - Bladesmith said:
Corby and Loveless bolts are probably the strongest. You only tighten then snug, not tight.
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Thanks Stacy and thanks again on the advice for making a gem stone handle knife my mom loved it! If I ever do my tests I’ll post them but if you say it’s bolts I’ll trust that you have the experience to back that stuff up.
 
In strength when we are talking about attaching scales, pretty much all the standard methods are secure. While one might be stronger than another, properly done any method from flared pins to Corby bolts will hold. Proper fitting and good epoxy will assure a solid handle that will last.

It is sort of saying, "which size lumber is strongest for a deck joist". Any board over 2X6 will be strong enough, but technically a 6X12 would be strongest.

Ron Frasier used to use a lot of 3/8" round brass fasteners that went on a 3/16" bolt (sort of like a loveless bolt). I asked him why he used such a large bolt and wide nuts and he said, "It sure won't come off that way."

I make a fastener from old brass cartridges like this image. It works well and looks great on a hunter. It is a bit of a trick to get it perfectly flush, but it is really strong. Makes one of the best looking take-down handles around.
1669553407300.png
 
Ive been moving to pretty much only peened pins. Have not seen problems with strength, inexpensive, look good, and are easier to install (no calculating drill depths or counter boring holes)
 
Stacy E. Apelt - Bladesmith said:
In strength when we are talking about attaching scales, pretty much all the standard methods are secure. While one might be stronger than another, properly done any method from flared pins to Corby bolts will hold. Proper fitting and good epoxy will assure a solid handle that will last.

It is sort of saying, "which size lumber is strongest for a deck joist". Any board over 2X6 will be strong enough, but technically a 6X12 would be strongest.

Ron Frasier used to use a lot of 3/8" round brass fasteners that went on a 3/16" bolt (sort of like a loveless bolt). I asked him why he used such a large bolt and wide nuts and he said, "It sure won't come off that way."

I make a fastener from old brass cartridges like this image. It works well and looks great on a hunter. It is a bit of a trick to get it perfectly flush, but it is really strong. Makes one of the best looking take-down handles around.
View attachment 1999989
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That is slick! - I might have to try that one of these days.
 
Josh1992 said:
Why is that? Isn’t there a chance of the tube will collapse?
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Collapse where? If hole in scale and tang are exact I don't see where the tubing could collapse or bulge within the build. I have been using 304 stainless tubing with 0.028 inch wall thickness, takes some major effort to flare.
 
Stacy E. Apelt - Bladesmith said:
In strength when we are talking about attaching scales, pretty much all the standard methods are secure. While one might be stronger than another, properly done any method from flared pins to Corby bolts will hold. Proper fitting and good epoxy will assure a solid handle that will last.

It is sort of saying, "which size lumber is strongest for a deck joist". Any board over 2X6 will be strong enough, but technically a 6X12 would be strongest.

Ron Frasier used to use a lot of 3/8" round brass fasteners that went on a 3/16" bolt (sort of like a loveless bolt). I asked him why he used such a large bolt and wide nuts and he said, "It sure won't come off that way."

I make a fastener from old brass cartridges like this image. It works well and looks great on a hunter. It is a bit of a trick to get it perfectly flush, but it is really strong. Makes one of the best looking take-down handles around.
View attachment 1999989
Click to expand...
I really like that! Thanks for posting this!
 
Cushing H. said:
Ive been moving to pretty much only peened pins. Have not seen problems with strength, inexpensive, look good, and are easier to install (no calculating drill depths or counter boring holes)
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That’s what I have experience in. In my practicing with pins I have messed up on two out of 600 or so. I have broken 3 scales but not in several years. I really like the look of 6-8 pins in the scales and 10 pins if you have bolsters. But it sounds like I should try the bolt method and see how it feels. I like this thread I’m getting some great input.
 
Seedy Lot said:
Collapse where? If hole in scale and tang are exact I don't see where the tubing could collapse or bulge within the build. I have been using 304 stainless tubing with 0.028 inch wall thickness, takes some major effort to flare.
Click to expand...
Sounds good I guess in my mind I always thought hollow tubes would be the least stable because air doesn’t have any strength to it. But I guess if you have enough force on the handle to dent the tube you would crack the scale anyway! Good stuff Seedy lot. By the way you have a great rep on bushcraftersusa forum
 
Isn't this just a limitation of scale construction? Lateral flex is just going to stress that construction. If you want something less likely to fail cast a thermoplastic around a hidden tang or do a stacked handle from some flexible material.
I say this as someone who's response to the use above is to give the person a hatchet.
 
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