I just tried squeezing a 1/8" flat head steel rivet against a load cell in the bench vise. It began to yield at close to 1000 Lbs and thickened, shortened and buckled by ~1500 lbs.
I've been looking for common items to use for rough DIY force measurements. 3/8" OD x 3/8" long copper tubing crushes starting around 500 lbs but like the rivet it has no sharply defined yield point. The serrations on the vise jaw may have blurred the initial yield point on the rivet. My smooth-jawed milling vise doesn't apply as much force and is too valuable to risk straining.
Aircraft riveting uses the gun end .401 dia. rivet sets to match the head shape of the rivet being set. The tail of the rivet should extend
1.5 times the diameter of the rivet before it is set. A flat bucking bar is used on the tail of the rivet and the gun with the proper rivet set is held on the rivet head. Hold the gun perpendicular or you will get a " happy" rivet, The set will make a smily on the metal next to the rivet head. As someone else said, you want to hit the rivet with a reasonably hard blows so you dont work harden it before it is properly set. When the rivet is set the tail end diameter should be 1.5 times the diameter of the rivet and not be crooked or oval.
If you have only a couple of rivets to set you can put the rivet set in some type of holder of vice and lay the piece to be riveted with the rivet in the rivet set. Hit the tail of the rivet with a hammer until it reaches the 1.5 diameter of the rivet. Make sure the sheets your are riveting are tight together. This is where Klecos come into use.
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As far a annealing rivets, it depends on what material the rivet is made of. Aircraft rivets for the most part do not require annealing. The most common rivet in aircraft use is the 2117 material. These require no annealing. The ones requiring annealing are commonly called " icebox rivets" because after annealing you either use them right away or put them in the freezer to keep them soft until you shoot them.
The working end of the ram on my press is just a square piece of metal. No nothing to clamp or affix anything to it. No hole in the end, set screws... You would need to make something if you wish to attach some sort of die to it. I've seen other, more expensive presses that look the same as these from China and they have a hole in the end for affixing attachments.
I have considered boring a hole into mine for this but haven't needed to yet for anything...
In some 20 years in and around USAF field maintenance shops I don't remember ever seeing an alternate method of setting solid rivets used. This is not to say that alternate methods didn't exist or that they weren't used, rather that the bulk of the rivets used were shot using a hand held rivet gun and bucking bar.
You might look into spinning rivets, such as is done to splice chain saw chains. There are simple bench tools and drill press accessories with two concave-rimmed bearings that roll the shank into a smooth round head. I didn't find a picture, but I ran one in a factory.
I used to file nail heads smooth in a drill press, cut them to length and set them with a ball pein hammer.
That's the way I read it. However, aircraft skins tend to be thin. Does this method work even is the pieces riveted are, say, 3/16" thick each? Will the force transmitted to the bucking bar be dissipated in the material?
I tried the same thing. I have no means to measure the force but my calculations suggest that the vise should be able to exert 3-5 tons of force. This is born out in practice by my efforts at embossing:
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Proper artists use 20-ton presses for this. I just squeezed the die etc. in my big vise with an extension bar on the handle.
I just got back from a garage sale with a 2-ton hydraulic jack ($2). I am thinking of making it into a press of some sort.
I think I saw something like that on Google images. A promo video for an orbital riveter suggested that the force required is 1/10th of the force normally required in the squeeze/hammer method.
Or you can use cherry lock or cherry max rivets when you cant get on both ends of the rivet to buck it. The only thing bad is the extra expense of the rivets.
I still have all my riveting tools from when I did aircraft sheet metal work. Some of the rivet sets are made to get around stringers and the like. If you plan your work you usually can avoid not being able to reach the rivets. I have a pneumatic rivet squeezer that I used once in a while but most of the time it was solid rivets with a gun and bucking bar. I never used explosive rivets. Just hit them with a hot soldering iron and they set themselves.
Most of the rivets used are 1/8" and are driven until they are expanded to about 1.5 D so it is not a major project to drive them. I'm working from memory here but the bucking bars probably weigh 1 - 2 lbs., or thereabout. The Driver inserts a rivet in a hole and presses the rivet set against it. the Bucker then presses the bar against the tail of the rived and the Driver pulls the trigger. The rivet gun probably hits the rivet 3 or four, maybe 5 times. Since the rivet is really held between the rivet set and the bucking bar little force is dissipated by the metal being riveted. Certainly when repairing a structure like a airfoil or a portion of a wing, or side of a fuselage; there is no distortion in the skin being riveted to the formers.
Gunner Asch wrote in news: snipped-for-privacy@4ax.com:
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In junior high school (mid-1960's), my best friend's father had a single box he'd picked up someplace. They were considered very precious, and we never experimented with them. I don't recall hearing that he had installed them on anything. He used to build all sorts of stuff, including a 24 foot sailing trimaran he got out one hull at a time. He was the one who introduced me to metal working & taught me a lot about electronics.
There IS noticeable distortion in the skin where it is riveted. Although we work hard to minimize it.
That's because the shaft of the rivets (diameter) also expands when the rivet is driven.
That's just a side effect of riveting thin metal parts together.
Using a larger number of smaller rivets would help reduce that distortion. Smaller diameter - lighter impacts to set. And better distribution of loads between parts.
Strange. I've worked on quite a number of C-47's, that were certainly old enough to have been assembles by humans, and never noticed any distortion of the skin :-) But you are correct that over driving rivets can certainly expand the metal around the rivet and cause distortion.
(I was actually thinking of the kind of distortion you get where you lean on the gun and the guy bucking is on a different rivet :-(
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