newbie struggle with rivets for tongs

[robert hanford]

Any help much appreciated. I struggle to successfully rivet my tongs. The rivet collapses and never peens right. I am working on my own and fumbling around a lot.... Any advice?

[ThomasPowers]

How much of the rivet are you leaving "proud" of the joint before peening? They have to be trimmed to the correct size you know.

[robert hanford]

How much of the rivet are you leaving "proud" of the joint before peening? They have to be trimmed to the correct size you know.

About half an inch... how much do you leave?

[Nakedanvil - Grant Sarver]

Should stick up 1-1/2 - 2 diameters, so a 1/4 inch rivet would stick up 3/8 - 1/2 inch. Hit straight down with a big hammer first, one or two blows. I rarely do rivets under 1/2" hot.

Any help much appreciated. I struggle to successfully rivet my tongs. The rivet collapses and never peens right. I am working on my own and fumbling around a lot.... Any advice?

Sorry, I don't understand what you mean by the rivet "collapses". And "peens" is what you do not what the rivet does.

[robert hanford]

Should stick up 1-1/2 - 2 diameters, so a 1/4 inch rivet would stick up 3/8 - 1/2 inch. Hit straight down with a big hammer first, one or two blows.

Is the rivet heated or can it be done cold?

[robert hanford]

Should stick up 1-1/2 - 2 diameters, so a 1/4 inch rivet would stick up 3/8 - 1/2 inch. Hit straight down with a big hammer first, one or two blows. I rarely do rivets under 1/2" hot.

Thank you for your help!

[robert hanford]

Should stick up 1-1/2 - 2 diameters, so a 1/4 inch rivet would stick up 3/8 - 1/2 inch. Hit straight down with a big hammer first, one or two blows. I rarely do rivets under 1/2" hot.



Sorry, I don't understand what you mean by the rivet "collapses". And "peens" is what you do not what the rivet does.

The end gets knocked over rather than mushrooming. Thanks for the correction.

[bigfootnampa]

One thing that I will guess that you are doing is to hit the rivet too hard when peening. Good rivet technique is MANY light hits done quite to VERY fast. Do you have the rivet headed on one side before setting it? If not you should. Then you need to have a bolster beneath the tongs that allows space for the previously formed rivet head. Accuracy is also very important, especially for the first few strikes any tilting or other than directly vertical strikes will be likely to get a bend started and basically this is small scale upsetting at first... bends are disastrous. The heavy blows that Grant uses serve to upset the rivet IN the hole making for a tight fit. Many light hits then upset the end of the rivet to form the head... heavier blows overtighten the rivet forcing you to loosen it at heat and will often bend the head over to the side. The principle is the same as in any forging, heavy blows carry their effect deeper into the steel... lighter blows have shallower effects... hotter steel moves easier and so the strength of the blows must be adjusted accordingly. As Grant mostly cold rivets he will use heavier blows than a guy who is hot riveting would. Speed is much less important for cold riveting too.

[Nakedanvil - Grant Sarver]

Tweechizone!

[pkrankow]

I have more success riveting with a 1# hammer instead of my usually 3# hammer.

If it bends over like a badly struck nail, do what you should with a bad nail...remove it and start over with a fresh fastener.

Phil

[Ratel10mm]

I was taught to peen rivets with the ball side of a ball pein hammer. Use the hammer to work around the outer edge of the rivet, mushrooming the rivet down to create a dome as far as possible matching the pre formed dome head (we were using bought rivets).
The important thing was to hammer the edge of the rivet & work it down, not the centre of the rivet.

[John B]

When I rivet tongs I just use a piece of round bar cut to length (the width of the thickness of the tongs when in position plus three to four times the diameter of the bar being used)

I also have a plate approximately twice the thicness of the bar being used, with a hole drilled through slightly larger than the diameter of the bar, this plate is placed on the anvil.

The bar should be an easy fit through the holes in the tongs.

As it is not essential to have a dome headed rivet, I create my own pan head or flat head rivet with the bar.

Get the bar hot, place it through the holes in the tongs and place the bar into the hole in the plate on the anvil, then using the flat (at an angle) or ball end of the hammer, lightly and quickly work your way around the top of the bar creating a larger dameter, then flip the tongs over, (no need for the plate now) and repeat on the other end of the bar, (Once you get used to this you can dispense with the plate and just hold the tongs at the height you need above the anvil)

I would then put the assembly into the fire and get the rivet area hot, and then flatten the ends down Flipping it over and working from both sides to create a flat head, work the tongs as you flip them to make sure they will still open and close, continue until you are satisfied with the heads at each side, then whilst the are is still hot, set the tongs to your desired size, then plunge them into the slack tub working them as you do so. They should work fine then when you come to use them.

If you are using a carbon steel to make the tongs you will need to normalise them before use or they may fracture, Mild steel will make adequate tongs

I hope this makes sense, it works for me, but there are many other valid ways of doing this.

Picture attached showing a typical one, tongs were spring steel from a coil spring, picture may be large, but you can see the rivet clearly, Good luck with your next ones,

[evfreek]

These are all really good comments on this thread. One more to add is to apply corrective action in the form of off center blows in the correcting direction once you see any bending. This helped me a lot. I saw a demo in which someone intentionally bent a rod before heading it, then upset into the bend. This makes an ugly little bent over blob. Instead of bending it back, however, the demonstrator moved the forming head to the edge of the anvil, and *forged* the blob back to center. There is no way you can tell that the head was not bent back. It was more pushed back. This is the essence of forging: working with the plastic deformation of the metal. After watching this demo, my rivet peening technique improved accordingly.

Also, don't be afraid of messing up. Like Phil said, cut off and start over. Or, just leave the bent over rivet there and try to do better on the next set of tongs. It may not last, but then just go back to step 1.

[Swamptroll]

When I was an apprentice toolmaker we had to make our own punches. We use O1 and a heading fixture. Most of these were 1/4" and smaller but the principle is the same as riveting. We used a 8 ounce ball peen hammer to cold form the heads. The metal slowly moved down into the heading fixture and expanded. We did hundreds of punches this way so I know that the cold forming can be done rather easily once learned.