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I never even bought a rolling mill


#1

Hello all,

I’ve been a lost-wax caster for over thirty years, and I never
really learned to use a rolling mill. I never even bought one,
because I could always figure out how to get along without it. I have
several questions for you bench experts concerning rolling gold wire.
For an upcoming line, I need long bands of 18K yellow gold to then
have disks punched out, 1/10th. of a millimetre thick and 8mm in
diameter. How many operations/reductions am I looking at to roll down
a 1.2mm wire to a 0.1mm x 10mm ribbon? Is this too thin to be done
reasonably? Could I do this, with good repeatability (thickness-wise
I’d like to stay between 0.09mm and 0.11mm), using an off the shelf
rolling mill? Do standard mills have well polished rollers, and will
I have a problem getting an easy polish on the ribbon after the final
reduction? I’m hoping to need about 10 meters a year, lets say 1000
pieces. What are the do’s and don’ts for doing these myself? Perhaps
I’d be better off getting them made? I have kilns and temp. control
for annealing. That’s no problem. I’d appreciate any and all ideas,
comments, etc.

B. Randall
http://www.srdfrance.com


#2

Even though a standard, off the shelf rolling mill can do most
anything if used with skill, this is probably not the place. You did
say you want to punch.1mm x 8mm circles? Thats about 32 ga. - my
gauge sizer doesn’t go below 30 ga. That’s roughly the thickness of
notebook paper. It can be done, for sure, but for the quantity you’re
talking about, I’d probably just buy it. It’s hard to put into words
some of the difficulties of rolling that thin. It’s easy for a small
piece, but for a long strip you start getting warping and the lack of
extreme precision comes into play more and more. The work will
develop a curve because the rollers aren’t THAT precisely parallel -
you can compensate, but it becomes more and more of a problem the
thinner you get. Again, yes, it can be done - no doubt of that. The
big refiners are rolling out 12 inch sheets, and using slitters to
get those perfect straight edges - you’re not going to get anything
like that by rolling a single wire into a strip. It will be more like
a sine wave or an arc. The tiniest little bend in your stock will
magnify more and more as you roll. If you said 22 ga. I’d say sure, of
course. But.1mm is mighty thin.

http://www.donivanandmaggiora.com