Making wire with rolling mills

Jewelry Discussion
21

Hi Jim,

We have designed a mill/grooves that now allows the reduction
rolling of round wire.

Starting with a wire of square or round section, use the mill in
same way as you would use square mill.

This will allow you to form round wires of different diameters.

The difference being that a round section will be formed before the
rollers are fully closed.

If you continue to roll and fully close rollers, this will create a
slightly oval wire.

To avoid flashing rotate the wire 90 degrees on every pass.

If flashing forms you need to reduce the amount of reduction on each
pass.

Matthew Durston

22

Perhaps, Matthew,

can you confirm that you have finally been able to programme a cnc
lathe to cut the different dia round grooves in your rolls, well
enough to make round wire at last?

I bought a durston from your father some 40 yrs ago. I motorised it
and its working well to this day.

it was one with the aluminium bronze? roll bearings. i carried it !!
to the train station. bit younger then, also I visited your father
for some extra side rolls shortly after.

ted Frater.
Dorset.

23

Just out of interest, have you compared this with drawing a wire?
Shape comparisons, maybe… do you have images of finished rolled
wire/rod?

There will of course be differences between rolled wire and drawn
wire, do you have any data that you’re able to share?

Regards Charles A.

24

Hi Matthew,

It sounds interesting I certainly look forward to trying it out.

Jim

James Binnion
James Binnion Metal Arts

25 
Since you brought it up, I've always wondered why there weren't
round wire mills previously. Round wire being used more regularly
than square.

I would guess it is because round draw plates are relatively
inexpensive, readily available, and work well.

Noel

26

To elaborate on Matthew Durston’s comment about how to avoid the
flashing that occurs when rolling stock through the square (or round)
grooves:

When an ingot is rolled through the grooved section of the mill, the
rollers exert a lot of pressure on that ingot, forcing the ingot
narrower, longer, and also sideways in the groove. So as force is
exerted on the ingot being rolled, the metal must be allowed to push
outward as it is condensed and elongated by the action of the rolling
mill. As long as some space is left between the rollers, the metal
being squeezed will push outward slightly, but ideally not enough to
form a sharp “fin” or flashing on the ingot. If the rollers are too
tight, or even touching together when you exert pressure on the ingot
being rolled, the pressure on the ingot will often “extrude” out of
the groove and form this unwanted fin or flashing on the ingot.

The square shape of the rollers are designed to assure a 90 degree
orientation of the wire being run through the rollers. The first
pass pushes on the top and bottom corners of the wire ( the 12
o’clock and 6 o’clock positions), and the second pass should have the
square ingot turned 90 degrees, so the wire is run through to press
the corners not previously rolled ( the 9 o’clock and 3 o’clock
position). After both rolls, all the sides of the square should now
be equal.

If the rollers are touching together while this process is being
done, expect fins to form on the wire’s corners, but then folded over
onto the ingot by the next roll. These fins are not easily seen after
the square wire emerges from the mill. When you start to pull the
wire round, a "shredding " of the wire seems to occur, which is just
those extruded fins being pulled off by the drawing process.

The chamfered bottom of the “V” shapes grooves help control stress
on the outer corners of the square shape being formed by the grooves,
helping to prevent cracking on a sharp-edged corner. It also works
nicely to “upset” even, flat edges on wide wire stock run through the
grooved rollers, to narrow and even the stock.

Not having used the new round rollers Durston has produced, I can
only assume one would use them much like the square grooves ( “V”
shapes grooves") in that the wire must be rotated 90 degrees for each
pass. A little trickier to do, I am thinking, as there is no corner
to calculate the 90 degree turn each time. Again, if the rollers are
too tight, I would expect a fin or flashing to occur. Keep the mill
open a bit to prevent this.

Jay Whaley

27

I suppose that having started making my own wire sometime in the
Calcolithic Age I just always thought that the purpose of the square
wire being formed on the rolling mill was just to reduce the ingot
in size prior to drawing it down through the appropriate profile draw
plate. I never in all my years thought that the purpose of the
rolling mill was to make finished wire. Is this a new practice for
the small shop? My poor old rolling mill is over a hundred years old
and I sure wouldn’t want to make finished wire with it, even though
it does make reasonably true square wire.

28 
There will of course be differences between rolled wire and drawn
wire, do you have any data that you're able to share?

Hi Charles, Jim,

This is a piece we rolled out. There are 2 different diameters. Both
ends have been rolled using the new round mill.

800×600 54.3 KB

Matthew

29 
I suppose that having started making my own wire sometime in the
Calcolithic Age I just always thought that the purpose of the
square wire being formed on the rolling mill was just to reduce the
ingot in size prior to drawing it down through the appropriate
profile draw plate. I never in all my years thought that the
purpose of the rolling mill was to make finished wire.

“Square” wire from my rolling mill is an octagon, there are no
square wire rolls I have ever seen on the mills jewelers use. The
round rod from a rolling mill will be sort of round not a true
circle in cross section. To get truly round or square wire you will
still need to draw it.

James Binnion
James Binnion Metal Arts

30

Hi Ted,

can you confirm that you have finally been able to programme a cnc
lathe to cut the different dia round grooves in your rolls, well
enough to make round wire at last? I bought a durston from your
father some 40 yrs ago. I motorised it and its working well to this
day. it was one with the aluminium bronze? roll bearings. i carried
it !! to the train station. bit younger then, also I visited your
father for some extra side rolls shortly after.

That’s interesting. That is the problem. They last too long.

Infact, the grooves are turned in first and then the final process
is grinding. - Grinding them in the past was always the more
difficult.

We have always had CNC grinders but last year we purchased a new one
which made the half rounds easier to do.

Matthew

31

Yup, the making of all forms of finished wire is very often done in
small shops. It often makes good sense to be able to make any shape,
size, and length of wire for the job at hand, not having to wait to
place an order, and waiting for your finished wire to arrive.
Besides, what do you do with the left-overs??

With my big Durston D2 120 mm double mill, we make perfectly square
(sharp corners and all) wire of any size, rectangular wire of any
dimension, and 1/2 round wire of any thickness and width up to 11 mm
wide. The 5 drawplates I have can make round wire or tubing of any
size from 10 mm down to 32 ga.

I think if your rolling mill is well maintained, in good condition,
and your drawplates are of good quality, you can make pretty much
anything you want in a small shop. There is obviously time and labor
involved, just like the process of metalsmithing itself.

Yes, you’ll have to make the decision of whether some wire is more
cost and time efficient to just buy on the roll, but for other shapes
and smaller amounts, just make them yourself. Oh, and some shapes of
stock ( colors, alloys, and karats) just aren’t available in any
catalog, and then you just make it yourself.

—Jay Whaley

32 
This is a piece we rolled out. There are 2 different diameters.
Both ends have been rolled using the new round mill.
http://www.ganoksin.com/ftp/image002.jpg

Thanks for that Matthew, that looks pretty round, I look forward to
seeing example used in pieces :slight_smile:

Personally I’m still trying to get my head around making 300mm sheet
squares, in the home studio it’s almost impossible.

Regards Charles A.

33

We have a range of drawplates are work, but we only use the round
ones. For square, D-section and court wire for rings, I use the
rolling mill, or if it’s a particularly large section, I’ll use a
mixture of forging and swages. The only time a drawplate would be
useful is if I wanted to make large section wire, like a 5mm
D-section, but I don’t have a drawbench, so I can’t pull through the
plates anyway. For the record, we use a Durston hand-powered mill
with square grooves and D-section extension rollers, still going
strong after a couple of decades, and the rolling surfaces are in
good condition.

Jamie Hall

34

I think that was what my post was trying to impart, thanks for
making it more understandable. My rolling mill from 1910 does indeed
make octagonal wire, my draw plates make it other than that. When
viewed under magnification drawn wire still ain’t exactly square
either, however it is getting a lot closer than with just the old
mill alone. Blessing on the person that invented the draw plate.