Is peening the handle pins necessary?

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petercrowell

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Oct 17, 2013
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I've been watching knife makers on youtube, in anticipation of my first knife-from-scratch project.

Several of them do not peen the handle pins. They epoxy them in and sand them down with the rest of the handle.

They seem to be competent knife makers with a lot of experience at making quality stuff.

So, it leaves me wondering if peening the pins is just one way, but not necessarily the superior way, of putting scales on a knife.

Any thoughts?

Thanks!
 
Peening does make them a stronger mechanical fastener than just epoxy. But that said, epoxy is pretty damn strong. So it is not always necessary - but may be preferred by some makers, and some buyers. Peened pins can also be functional, serving as an indexing point on the handle.

I have some favorite makers who do, and some who do not. The style (and overall fit/finish) of the knife is also important - a perfectly peened pin is a nice detail and further demonstration of craftsmanship.
 
I dont think its an absolute necessity with the modern epoxies we have, but it certainly cant hurt.

I personally dont peen them but I do make sure I drill extra epoxy holes in the tang and divot the insides of the scales as well as cut grooves in the pins before glue-up.

someone with more experience should be along soon to give you a better answer.

EDIT: looks like Liam has already answered.
 
I used to peen the pins every time I made a knife...even 1/4 inch pins but I stopped doing it for 2 reasons...first, I found that that I would shape the scales of the knife and grind away the gripping part of the pin so It did not matter if I peened it and second, I had a couple knives develop stress cracks either instantly or a week later because the pin put too much stress on the scales. I now will cut grooves with a Dremel cutoff wheel along the tang and do so at an angle so the epoxy will form a claw under the scales . I cross hatch the grooves and drill extra holes and make some grooves in the scales also. 24 hour epoxy holds them together hard. ,If the knife is requested to be for hard use I convince the client to ask for Corby bolts or Loveless bolts which I prefer. I have made and sold over 300 knives and have not had one come back yet because the scale popped off or came loose. I offer to replace, refund, or repair any knife I sell and my customers rest easy. On large knives I have put short sections of coarse thread machine screw through a hole in the middle of the tang and hidden pockets in the scales and I usually take a photo while doing it to show the customer how well made the knife is. I am probably not the only one doing this. Larry Lehman
 
I make a lot of fairly inexpensive kitchen knives- I tried all kinds of ways to make the handles without pins and ended up disappointed- carbon steel in the kitchen is kind of a tall order, since corrosion wants to creep under the scales and they're always hot, cold, wet, dry, or being pried on.
What I finally worked out was to use West Systems GFlex, sand the steel bright then wet sand it using a little epoxy just before assembly (I got that from the tech guys at West Systems- they claim it doubles the bond strength. They suggested wire brushing, but I felt that wouldn't be effective on hardened tool steel so I use a bit of worn ceramic belt- doesn't seem to shed grit).
When dry, I use a taper reamer to make the holes slightly hourglass shaped: if you get the length of the pins right and don't beat em down too hard, it fills the hole real nice, swells to bind the scale tight, and sands off flush.
IF IF IF IF (and that's a big IF) you never get any hint of corrosion under the scale, plain pins will hold if glued in. That's not strong enough for me. Probly work on stainless.
Think about all the old kitchen knives you've ever seen: yup, corrosion under the scale. The "cutler's rivets" are coming loose, and those old oak handles are gonna pop off any day now.
 
Thank you for all the replies.

I like the idea of peening, but I worry a bit about the handle cracking down the road. So, two more questions:

Is there some secret to peening so that the handle won't crack?

Do Corby Bolts reduce the likelihood of cracking?

Thanks for all the suggestions. I really like the idea of "claw grooves" and using a sheered off screw on the inside of the handle.
 
I peen most pins. Well maybe peening is a little too strong. I use a small ball pein hammer and tap on them to swell them up and fill up the slightly oversized and not perfectly round hole. It helps get rid of the halo when you sand the pin flat to the handle if your holes are too oversized.
 
petercrowell said:
Just curious, could you describe what makes a perfectly peened pin?
Click to expand...

1. Fills the drilled holes completely (function).
2. Even and smoothly polished domed heads (fit/finish).

But mostly it's one of those, you know it when you see it moments for me...
 
Last edited:
petercrowell said:
Just curious, could you describe what makes a perfectly peened pin?
Click to expand...

I take one of those tiny tapered diamond cutters and flare the pin hole slightly, and not too deep. Allows the pin to flare, and actually work as a mechanical fastener. Go easy on all steps.
 
Often, when I pin mortised handles on, I make a pin "socket" to hold the handle and to eliminate all the lateral stress on the handle material.
Drill pin holes:


Counter sink holes for sockets made by drilling 1/8" hole in 1/4" stock:



Epoxy in place:



When you peen the pin, it smooshes laterally into the socket, holding it very tight.

This is how one looks when sanded smooth.


This is how they look when left in the peened condition:




 
Karl, that's pretty frikin cool! if you don't mind I'm gonna steal that technique!
 
I think it depends on what kind of knife you're making... If you're making knives that will never be treated roughly (light prying, twisting, chopping) then I don't think it is necessary.

However if you're making a knife that will see rough use then epoxy is not enough. Especially if you're only preparing your glue surfaces by sanding.

In my testing sanding steel and micarta and gluing them together with nice epoxy (West Systems) created a joint that could be pulled apart by hand (the micarta was overhanging the steel so you could get a grip). Changing to sandblasting for prepping the glue surfaces hugely increases the surface area (and strength) and made it so that vice grips were needed to get the pieces apart.

Even with that I still recommend peened pins. I counter-bore my pin holes and then peen into the counter-bores as opposed to counter-sinking. This allows me to sand/grind the end of the pin without running the risk of grinding off the expanded part.

With those two things together I can abuse my knives without fear of the handles delaminating. I mainly treat the epoxy as a way of sealing the underneath of the handle and keeping moisture away from the tang...

I understand that dealing with abuse is not necessarily the right goal, but I like to make sure that I'm meaner to my knives than my customers will be so that I won't see any failures in the field!
 
Karl's method is an old one used for centuries. It is called "Cutler's Riveting" in some old books. That is a bit confusing since the two part hammered together rivets currently used on mass produced knives are called Cutlers Rivets ( because they look similar to a real Cutler's Riveted Handle).

The old standard for cutler's riveting was to use a copper washer for the rivet shoulder and a soft iron rivet. The washer was often chamfered to make the rivet fit very tight and give a rock solid handle attachment. In those days there wasn't any epoxy to make the joint stronger. Many 100+ year old knife handles attached this way are still tight as the day they were riveted.
 
Very cool method for sure. I had been considering doing the same thing to eliminate some crazing that I was seeing around the pin holes when peening pins in G10, however I solved the issue by just having a lighter touch with the hammer instead... I will keep that technique in the back of my head for future use though for sure!
 
When I do a full tang, I peen the pins or use loveless bolts. The thing with a full tang is that with sideways pressure the handle is trying to pop off. With a hidden tang and solid handle and guard it acts as one unit. I use small drill bits and drill shallow holes at an angle in the underside of the handle material and have the tang skeletonized so there's plenty of room for epoxy and plenty for it to grab. Still don't fully trust glue. One other thing, anytime you've got wood and metal, the bond will eventually break, one expands and contracts at a different rate than the other. Only time I don't peen is when I've used mycarta with mycarta pins on light duty knives, they are the same material and expand and contract at the same rate.

Ment to add that the way I peen is after epoxying the handles on and drilling the holes I shape the handle to 95% or batter. Basically all that is left is hand sanding. Then counter sink the holes a bit and peen. That way I don't grind the upset off the pin, and get even pins that are the same size and don't look like there peened.
 
I have a few old knives from my Great Grandfather's saw mill that have the old style cutler rivets. They are very strong, but I think Karl has improved on the idea. The ones I have, are a relatively thin copper washer with a mild steel pin passed through and peened.

Karl's method has what I would call a sleeve or collar... that's a lot beefier. :thumbup: :)


Corby bolts, Loveless bolts, etc. are very strong and hard to screw up.

I like to do domed pins on a lot of my knives... so the pins end up a lot like a miniature version of the rivets you see in old iron bridges. It's a strong mechanical fastener, but also a decorative touch.
 
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