Thread: How many tonnes?

I'm no expert at all!
I can see however that it will not be quite as simple: you are making a "head" in your "nail" of 3mm diameter from 1mm diameter wire - or 4mm diameter from 2mm diameter wire. Did I understand that correctly?
The head of the 1mm nail will occupy a volume of 1.5mm sq x Pi (3.1415) x height. If that was just 1mm thick/high, then you would have to squash/deform around 9mm of 1mm wire into that space (if the 'head' was 2mm thick it would become 18mm of wire). I doubt you would be able to do that without the copper wire curling up into any old shape in the process if you tried to so it cold and in one 'hit'.
My guess is that you would have to do that progressively in multiple operations - at a guess 2mm at a time - in 9 progressive upsets - into progressively larger cavities with progressively larger forces, as copper work-hardens quickly. You may even have to have anealing cycles in between to stop it fracturing....
Hope that doesn't put you off.
A thought outside the box: could you use annealed 3mm wire and stretch is down to 1mm for the bottom pin? Be some sort of 2-step process of stretch-upset to get the sharp transition you show in the drawing.

Joe

I see what you're saying, certainly puts things into perspective. You understood it correctly, the dimensions however I just had another go over and looks like I'll be dealing with even thinner material (1mm) with approximately 0.5mm overhangs, not sure if that's possible with basic equipment.

I'm not doing this on an industrial scale so I don't have access to stretching equipment that you suggested. I think I'm in the process of a rethink of my design hmm. Interesting how something simple on paper gets translated into such a mountain in the real world!

Sometimes it is better to out source work. It might be a lot cheaper and quicker to try and buy what you need. Whatever you thoughts on buying made in china might be, in this case it might be worth looking at.

http://www.globalsources.com/manufac...per-Rivet.html

or maybe there are some here that will work for you. you need to scroll down a bit. they have copper rivets in 1/32" dia (slightly smaller than 1mm)

Rivets, Rivet Snaps & Doming Blocks at Model Making Supplies UK

bollie7

Really nice description of the issues Joe. Eyeballing it I came to precisely the same conclusion, but there's no way I could have described it as accurately or eloquently as you did.

For 1 mm wire I doubt it would need a hydraulic press at all, I think something lever operated may be sufficient. I'd try in a drill press and use the quill as an arbour. You may find a lot more information on the net if you search for "riveting model steam" or similar, as a very similar operation is used in riveting solid rivets.

Pete

Have you thought about the possibility of turning them up on a jewelers lathe?

Start with whatever size is the max and machine from there.

Those little lathes can turn out some very fine work.