I am looking for a reference table that will provide guidance on
what shape and size the original stock must be to roll out to a
desired finish shape and size. As an example, I need three feet of
2X5 flat stock. What size round or square wire will roll flat to
this finished size? Thanks. Rob
Rob Meixner
Hi Robert,
Some time ago I did some experiments and some mathematical curve
fitting to derive a formula for doing this. The formula is quite
messy so I designed a program for it, that my son created and placed
at
http://www.ganoksin.com/gnkurl/ep81h8
Its not 100% accurate, but sufficiently close for all my
requirements in silver, gold, platinum and palladium.
In your example, it states that you should start with square wire of
side 3.684, or round wire of diam 4.157.
You can also specify the required length, and it will tell you the
length of stock to start with.
Because its very unlikely that you will have stock of this size, it
allows you to specify the size of the round or square stock you do
have, which you can then roll down to the size you actually need.
In your example, if you wanted a length of 45, and had some round
stock with diameter 5. It tells you start with a length of 22.9,
which, after rolling to 3.68 square will have a length of 33.2. If
this is then rolled to a thickness of 2, it will have a width of 5
and a length of 45.
After getting the stock to the required starting size, anneal it and
roll to the required thickness in as few passes as possible.
Let me know how you get on, or if you have suggestions for
improvement.
Regards, Gary Wooding
It has always made sense to me that, if the cross sectional area was
close in the start to finish pieces, then what shape it is in
doesn’t matter. When I do this calculation, I get the kind of
results that your calculator renders, however, when I do the
rolling, something else happens. I will try again. Thanks for the
calculator. It is exactly what I, and probably others, need. It
could be added to the Metalsmithing Suite too. Since I use a lot of
2X5 stock, I should probably buy a draw plate, but I am having
trouble finding one that does 2X5. If anyone has suggestions please
pass them on. Thanks. Rob
Rob Meixner