Questions about drawing non-round wire.

[Icarleug]

I tried to find some information about how to pull wire through a drawplate to form non-round wire, but could not find any conclusive information to about how to do it (well, other then to obviously pull it through the plate).

This is mainly to make oval wire for rings in the case I cannot get it in the size I want, preferably from round stock since I don't own a rolling mill.
I assume the process of drawing it is like drawing round wire: find out what size hole the stock will go through, taper it and pull it through the next smaller one in succession until you get the size you want (with a drawbench if necessary), annealing occasionally.
It is mostly the plasticity and (de)forming of the wire that concerns me.

If we take an oval as an example, in case I wanted a 4x2 mm oval, which stock would I begin with?
Assuming a 100% stretch in the length of the wire I would need a stock wire of 4x4 mm.
If however it all stretches to the sides I would just need a 3x3 mm wire (well, actually a little bit smaller, but close enough).
I suspect it is somewhere in between, that is that the stretching is quite uniform until it has filled the oval, then it will just reduce in size.
Also I wouldn't want to force the wire into a shape that would compromise its integrity, such as making it crack when soldered or cold-worked later on.
Do anyone have any experience with drawing oddly shaped wires, and if there is any difference between silver and the different carats of gold?

/Andreas

[Dennis]

Most of my work is made from non standard wires, so yes I draw it down all the time, 'though I don't agonise about it too much and just try to imagine what thickness and what length I will need to start with.

If you want to be certain and don't have the brains of Einstein, then you might have to test it first with copper wire. If you anneal every three or four passes, or when it feels very stiff, your metal will not be rendered unfit for use.

Once sufficiently drawn, I sometimes want it to be rod like, so I anneal again and stretch it, knowing it will become a tiny bit narrower.

In general, I make oval and triangular wire from a larger size of round wire. For a rectangular profile I start with square, begin to roll it flat, and then finish by drawing it. Drawing rectangular wire is the most difficult, because it tends to bind in the draw-plate, so the lead in must be very tapered. Dennis.

[Icarleug]

Thank you, will get me some copper wire to practice with before drawing anything more expensive.

/Andreas