Trouble Peening Rivets
I'm having a lot of trouble peening rivets. At a 1/4 inch I can't get a big enough round section to match the pre-peened nail head. At 1/2 inch I end up bending the nail as the head mushrooms out. I've been using a 5 oz hammer, and my initial thoughts are that it may be too light, but not sure.
I found that if I bend the shank while peening, the shank is too long. I clip my shanks as low as my snips can reach.

I also found that 100 rivets later I no longer had any trouble peening. :)
I was always taught that a rivet should extend above the block (or other containing surface) by a height equal to the diameter of the rivet. So, if you have a 1/4 inch diameter rivet, the rivet should extend 1/4 inch above the surface being riveted (whether that is a plate, pommel, etc.). Similarly, a 3/8 diameter rivet should stick up 3/8 from the surface.

In addition, I find it helpful to work around the rivet in a circular pattern as I peen. I usually start at the edge, work in to the center, and then work back out, but that can vary depending on the circumstances. Working in a circle may just be one of those superstitious things, but it makes sense to me that it would help even out strikes. If you get a small bend to one side and then keep hitting that side, you might make the bend too extreme before you even realize there is a problem. By working around in a circle, you will strike on the opposite side relatively soon and may bend things back the other way.

Personally, I would much rather use a lighter hammer and have to hit more times (especially if I've been having trouble) than use a heavy hammer that will mangle things in fewer blows. As with many things, where you hit is often more important than how hard you hit, so stick with the lighter hammer until you are comfortable with your hammer control (which probably means getting to a point where you can salvage bends in slightly too-long rivets). Moving up to a heavier hammer will get the job done faster, but without hammer control it will also destroy your work faster.

Lastly, If you are trying to match a pre-existing rivet head, you will almost certainly need to use a rivet set (a domed tool that helps form the rivet to the right size and shape). I rarely do things where I am that worried about symmetry, so I don't use a rivet set often. When I do, I find it easiest to start peening the rivet manually, and then switch to the rivet set once I have a workable mushroom shape started. Also, I find that heat is all but required when using a rivet set on material larger than about 1/8 inch (your mileage may, of course, vary).

-- Greyson
Thanks Greyson and Harry. Looks like your tips and more practice will set me up for success.
It may help to take a pointed punch and indent the center of the rivet post. This will help 'split' it (so to speak) and get you started.

Also having a sufficiently heavy or strong base to rivet upon. A sledge-hammer head is a convenient anvil that you can turn in various directions for the purpose, or a very large ball-peen hammer. This helps by 'reflecting' (not sure if that's the word I'm looking for) the force of your hammering rather than giving under it which wastes energy.
Thanks Jeffrey. My vice has a nice flat section that I've been using. I think I've come to the conclusion that I've just got too much nail left on the other side to mushroom successfully. I need to cut it back to 1/4" or 1/8"...also I feel like the biggest idiot because I've been practicing with pieces of scrap wood...which obviously behave differently under stress than metal. I'll get some practice in tomorrow with steel in order to simulate the actual riveting of a weapon socket. If all else fails, I can use langet nails instead (which are historically appropriate to the best of my knowledge). I can clip the ends of the nails, have them meet in the middle, and fill the pilot hole with good 'ol JB Weld. I'll end up with a solid rivet one way or the other!
Forming rivet heads can be very frustrating if you are missing fundamentals.

You're using nails for rivets, and you are attempting this cold, wanting a peen as large as the nail head ? I don't think you will get this result with your technique.

Nail heads are die-formed . You cannot get the head large enough by hammering without bending over the nail, as you observed. This is largely because the nail is such a small diameter. Sourcing some steel round stock even slightly larger than a nail would help your plight immensely . Also, doing it hot is vastly easier ! If you have a simple propane torch to heat the end (again, the context is a larger diameter rivet shaft) , you will find it much easier.

As has been mentioned by others, having some sort of anvil under the opposite side is crucial. The vice will certainly work, though not as well as something that wasn't hollow, if its the part of the vice I am envisioning.

Hope this helps
Thanks Isaac. I hadn't thought of working with small diameter round stock. I'll give it a shot.
And you've annealed them?
Isaac H. wrote:
You cannot get the head large enough by hammering without bending over the nail, as you observed.

Hmmmm.... I use nails now instead of rivets, when possible, because nails are a lot cheaper. I see no difference at all between peening rivets and peening nails.

Mark mentioned annealing. Good point. Do not soften the rivets, they become too difficult to peen properly when they're soft. Sometimes the rivets even crumble. Leave the rivets hardened. (EDIT: this may not apply to steel rivets, I don't peen many steel rivets)
Getting a nice, domed, smooth head on a rivet is easy - IF you have the correct tool ! . Google "Rivet Set ( or Sett) to see what the correct tool looks like. As far as I know..you can get rivet sets at some leather-working hobby stores. The ones you can get there are mainly for copper rivets..but they can be used for other metals.
Harry Marinakis wrote:

Hmmmm.... I use nails now instead of rivets, when possible, because nails are a lot cheaper. I see no difference at all between peening rivets and peening nails.

Mark mentioned annealing. Good point. Do not soften the rivets, they become too difficult to peen properly when they're soft. Sometimes the rivets even crumble. Leave the rivets hardened. (EDIT: this may not apply to steel rivets, I don't peen many steel rivets)


A most fascinating commentary. The comment Mark made is to affirm that he DID indeed anneal the steel. It is not my intention to appear condescending or impertinent , but you need to review some principals of basic metallurgy . If you are peening steel rivets, or in fact trying to work steel in any way whatsoever when it is cold, it needs to be annealed (soft ) . This also applies to non- ferrous metals, to a lesser degree. Trying to peen hardened steel is preposterous, and will result in the steel cracking or shearing instead of spreading out with plasticity. This is a fact, and any other experienced metalworker will confirm this....

Let's not confuse folks. No one wants a rumor going around that you need to harden rivets before peening because they are " too difficult to peen properly when they're soft" . You want them as soft as possible . The steel will work- harden as the peening process takes place.

In regards to the nails, yes, I agree that they certainly work effectively. My statement earlier was in the context that Jonathan wanted the resulting peen to be as large as the corresponding nail head. Such is nearly impossible to do cold, with such a small diameter shaft.
Yeah, I don't peen many steel rivets, as I said. I found that annealing brass and bronze rivets made then misbehave, like little toddlers. Last year I made something with over 200 1/8" brass rivets, and I annealed them all. It was a disaster trying to get them peened properly - too soft. I went back to using rivets that had not been annealed, and everything went smoothly. I suspect the steel is hard enough that you need them softened, but with softer metal like brass and bronze, annealing them is unnecessary and even counter-productive.


Last edited by Harry Marinakis on Sat 14 Nov, 2015 5:04 am; edited 1 time in total
One can also use screws, then file off the head to suit.

Cheers

GC


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Thanks everyone for the discussion and info. I think I've actually decided to grind some nail heads to look less manufactured and more elegant. I'll clip them to half the length of the haft then JB Weld the holes and the nails.

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