How to attach pins

J

jawilder

Joined
Jun 27, 2006
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when using brass or SS pins in handles, do they need to be peened or just glued?

If peened, exactly how do you peen and with what force/hammer?
 
I have only used brass, and I peened it by doing the following:

Get a piece of brass rod about 1/4-1/2" longer than what you need. Slide it through the pin hole, and use an anvil-type surface and hit with a ball peen hammer with a fair amount of force (more than just light taps) a few times until the pin does not slide at all. Then I hit it an extra time just for extra strength.

Of course, this is all done after the epoxy is on the handle.
 
go mike said:
I have only used brass, and I peened it by doing the following:

Get a piece of brass rod about 1/4-1/2" longer than what you need. Slide it through the pin hole, and use an anvil-type surface and hit with a ball peen hammer with a fair amount of force (more than just light taps) a few times until the pin does not slide at all. Then I hit it an extra time just for extra strength.

Of course, this is all done after the epoxy is on the handle.
Click to expand...

Do you wait for the epoxy to dry before this or while everything is still wet?
 
I do it while it is still wet. The pins really help to hold the scales in the right place while it dries. And I use 60 minute set time epoxy.
 
While that advice may work for some handle materials, it is not the correct way.
Peening should be done with a small hammer, using light blows to deform the head only. Leave no more than 1/16 exposed on either side before peening.
Using heavy hammer blows can bend the pin, and split your scales.
 
Good way to do it without peening is to have a tight fit on the pin. We do this by using metric size drills (example: 1/4" thong is drilled out with a 6.4mm drill) to get a press fit.
You don't want to peen very much depending on the handle material, a press fit of the pin and handle with the epoxy will hold. You can find charts on the internet to show sizes. We buy different sizes of metric drills to give us clearance and size for bolts, pins, and thong tubes.
 
You can try grinding a cone on the end of your pin before insertion, that way when you peen them they tend to expand the body of the pin instead of just rounding over the head. If you have a slightly oversize pin hole, this helps to hide your boo boo to an extent, but go slowly.

One must be careful to avoid splitting the scales by expanding the pin too much with this method. I always let the scales set up before pinning, but thats just me, I feel that it gives the scales some support against splitting if I peen a tad too much.

Chuck
 
Jason, are you making slipjoint's or fixed blade knives ?

If fixed blades, I do it a bit different than the first replies. For an 1/8" pin (.125) I use a #30 drill (@.129). I rough the pin up, degrease, apply glue (I use Loctite 324 + primer) and slide it into the #30 holes in the already glued up scales and tang.
For 1/4" pins (.250) I use an F drill (@.257)

I don't peen any pins on my fixed blade knives :)

OMMV ;)



:thumbup:
 
The object of peening is to NOT expand the shaft of the pin-only the head.
 
Bill DeShivs said:
The object of peening is to NOT expand the shaft of the pin-only the head.
Click to expand...

I understand peening only the head over, but I was under the impression that if I did that, and then proceeded to finish the handle out that I would remove the peened portion of the pin. That would leave only the epoxy bond holding the pin correct?

I thought that by expanding the body of the pin slightly,I was ensuring that I was getting as much mechanical bonding as was possible with pins and not relying on the epoxy alone.

I'm still learning.

Chuck
 
I expand the shaft and the head. This is the same thing that pin presses do and will ensure the strongest bond. On fragile materials you do have to be more careful about how much pressure is being put on them.
 
chuckinohio said:
I understand peening only the head over, but I was under the impression that if I did that, and then proceeded to finish the handle out that I would remove the peened portion of the pin. That would leave only the epoxy bond holding the pin correct?

I thought that by expanding the body of the pin slightly,I was ensuring that I was getting as much mechanical bonding as was possible with pins and not relying on the epoxy alone.

I'm still learning.

Chuck
Click to expand...

I ream the hole slightly to allow for a little expansion. That way there is still a good mechanical bond after the pins are ground flush.
 
If you chamfer the edges of the pin hole, the head will expand into the chamfered area. Then you can finish the pins flush. Trying to expand the entire pin is an "iffy" proposition-they will bend easily, rather than expanding uniformly.
Cutler's rivets, on the other hand, are made to expand into an oversized hole. They are inexpensive, and the heads can be turned down to whatever size you need. You just tap them snug with a hammer.
 
Actually we were on the same page after all. I have been chamfering the hole slightly( I believe that it is a 17 degree chamfer) and then peening the coned end.

I was not entirely clear when I said I was expanding the body of the pin, as I am only expanding the top portion of it to fill the chamfer, leaving I would assume about 50% of the pin unexpanded.

Chuck
 
I am unsure that countersinking and grinding flush will leave a round pin, (edit, Unless the countersink leaves a round hole and the pin is peened evenly) is there a recommended way of spinning the peened head into a nice rivet?
 
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The countersink will leave a round hole and if the pin is expanded completely it will fill that hole. The handle should be basically finished at that point, so you're not going to significantly change it. The pin shape will come out basically the same as it would if the pin were straight through.
 
I don't peen mine at all. I just stick them in before glue up then grind them down with the shape of the handle. If you use a good glue/epoxy, peening them is probably pointless.
 
If you peen them, using a good glue or epoxy is probably pointless!
 
I prefer to peen and use glue, just for the extra safety of either situation. I don't want the epoxy failing and the handle falling off, but also I don't want my peening job to be bad so I epoxy it.
 
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