How do pins work?

Pins are used to affix parts of the knife together. They are used for pivots on folders.
Properly used, pins are flared (peened) on either end to hold the parts together.
Improperly used, they simply keep parts in place by preventing lateral movement.
 
Reading Bills response bring a question to my mind.. how many of you peen your pins? I usually place them "improperly"
 
I don't peen my pins. My theory is, the epoxy keeps the scales from falling off and the pins keep them from shearing off.
 
I used to just use epoxy and pins, but I have just been peening them lately. in my tests the peen is the strongest way to attach scales, I still like corby bolts a lot (very clean and fast) but the peen in my opinion is still stronger. I tested a knife with peened 3x 3/16" SS pins and God him self would have to pry those handles off.

There is nothing wrong with pins and epoxy ( I never had any handle failures) but I personally like the peace of mind that corby bolts and peened pins give me, especially with my combat knives.

-Josiah
 
I'll have to practice peening, just in case a client requests it. I'm not against the idea by any means, I just haven't really found it necessary.

Josiah, I believe you that peened pins alone are strong enough, but I think I would still use epoxy. I like the idea of the tang being sealed against moisture. (although I admit I don't how waterproof epoxy actually is, I imagine it varies between brands/types)
 
James_Terrio said:
I don't peen my pins. My theory is, the epoxy keeps the scales from falling off and the pins keep them from shearing off.
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I do it this way too but add one more step: I like to leave them proud and spin a dome on each one. I super glue them in so they dont spin in the hole. With a small dome they tend to help keep scales from lifting too.
 
Just trying to teach you guys the classic methods.
You hand forge your blades-you should peen your pins-epoxied or not.
BTW-you need a little hammer, not the forging hammer.
If anyone is really interested, I can do a tutorial.
 
Bill- I think you and I just march to the beat of a different drummer... but I'm still tempted to ask. Why does a guy have to pein pins if he hand forges his blades?

If I'm following that... then he should also only use files, maybe an old treadle style grinding wheel, harden with a coal fire and temper in molten lead....etc.
 
Bruce Bump said:
I do it this way too but add one more step: I like to leave them proud and spin a dome on each one. I super glue them in so they dont spin in the hole. With a small dome they tend to help keep scales from lifting too.
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I presume there's a special bit or tool for this? Domed pins look really cool; I just haven't quite figured out how to do it :o

Bill DeShivs said:
Just trying to teach you guys the classic methods...If anyone is really interested, I can do a tutorial.
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You post it, I'll read it and try to learn it. It seems like a good skill to learn and some customers might insist on it. I'd hate to turn down work just because of that.
 
Pins were used two thousand years before epoxy was invented. Today peining pins is used mainly on folders, where the pin is the sole holding device for the scales and spring, and often are the blade pivot,too. It takes skill to pein them right and get a good tight joint without damage of overtightening the blade and spring. For what it is worth, technically if it is peined a pin becomes a rivet. If it is not, it is a pin ( in knife descriptions the opposite terms are often used). No one will ever start calling them "Mosaic Pins" ,though.

To pein a pin (into a rivet) the pin should be a good fit for the hole, but not too tight. The ends of the hole should be chamfered about 15 degrees to allow for the rivet to expand, thus locking it in place securely. If the material is too fragile to allow for a rivet that expands in the scale, then a domed head is used.This is often the case with antler,stone, and MOP. This is done by making the rivet slightly longer than the scale thickness, either carefully hammering the rivet into a domed head, or using a rotating cup tool to 'turn' the head (called a head spinner - available from the knife suppliers).

A side note on peining scales, and especially bolsters, is that the hole in the tang needs to be loose to the pin. If it is a snug fit, the pin will expand at the tang when being peined, and swell the rivet under the scale or bolster, thus lifting it and making a snug fit impossible. Harder hammering will just distort things and make matters worse.

Nearly any malleable metal can be riveted, but the softer ones are preferred. Copper, brass, nickel, and silver are common. Steel is often used for the pivots on folders.

With modern epoxies, drill presses, and other advances, peining is not necessary for many knife types. The use of high grade epoxy and proper handle assembly will assure a handle that may outlast many generations of owners. I rarely pein the rivets ( technically pins ) on fixed blades. Using epoxies, like T-88 , should not necessarily need pins or rivets at all, but the look is better with them on scales (and the added security against lateral shearing is a guarantee with them in place).

Stacy
 
I not only peen the pins to rivet the scales on full tang knives, but also like to ream the holes with a tapered reamer so upsetting the pin is progressive to the outside of the handle. I then anneal my pins before use, and as Stacy suggests, stick to soft materials like copper and nickel silver. They expand the best without creating undue stress on the handle material.
Just an old-school habit, I suppose, but one I stick with. It may be overkill, but the handle certainly isn't coming off.
 
Pins can be peened and countersunk flush, or left with exposed heads. They should never be hit so hard as to expand the shaft of the rivets. This is why scales get broken. Annealing soft metals can make them TOO soft, and allow them to bend or expand.
Spinning rivets is used in manufacturing, and is not particularly useful in hand making knives.
Nick- I just thought that since most of you forge that learning to properly set rivets would be of interest. There is much conjecture that forging does not produce a significantly better blade than stock removal, so why bother? Or, why not learn to properly rivet?
 
Bill DeShivs said:
Pins can be peened and countersunk flush, or left with exposed heads. They should never be hit so hard as to expand the shaft of the rivets. This is why scales get broken. Annealing soft metals can make them TOO soft, and allow them to bend or expand.....
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Well, I suppose that's a matter of opinion, Bill. I forget where I first learned that, but it was most likely from a book by a knifemaker. It certainly pre-dates me. Not to mention, it's worked well for 28 years now and I've never once cracked a scale on a full tang knife or had a knife come back. I'll let my successful use of the technique speak to its effectiveness for me. Others mileage may vary....
 
Having read everyones post on why they peen or not and that with the epoxies of today being so strong you do not have peen if you do you do not want to. I was always told that the epoxy while being a very good adhesive was manly used to keep out the water or moisture from getting between the scale and the blade, so I will usually peen unless it is a mosaic pin.
 
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