August 2019 67
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Gimmel Rings
couple then returned to Thailand with the
intention of returning to the UK for their
wedding in June.
I decided to experiment with copper,
and the initial results were suffi ciently
encouraging that I emailed to say I could
make them, and could they get their fi ngers
measured for size? They agreed the price
and I got to work.
This is the story of how they were made.
The cross section of the fi nished rings
was to be as shown in photo 3.
Notice that it’s a little deeper than half-
round, with slightly rounded corners. The
actual ratio is 4:3 and I thought it would
be no problem to create this with my
rolling mill.
Photograph 4 shows my rolling mill, the
main rollers of which are 65mm in diameter,
with a fl at section for rolling sheet metal,
and a set of V-grooves for rolling square
section rod or wire, see photo 5.
The axles of the rollers extend through
the right-hand pillar and accept pairs of
short auxiliary rolls with grooves of various
sizes – photo 6 shows a pair for forming
4mm half-round wire.
My plan for making the 4mm ring was
to start with a strip of 4×2mm wire. I didn’t
have any 4×2mm wire, but I did have some
5×5mm. Calculations showed that 39mm of
5×5mm, when rolled down to 3.175×3.175mm
in the square rolls, could then be rolled
down to 2mm in the fl at rolls to become
4mm wide and 120mm long. I could then
fold it in half to make a 4×4mm cross
section, and then twist the central section
by 360°, as shown in photo 7.
This piece was then passed through the
V-rolls to create the square shape shown in
photo 8.
The next step was to pass it through the
4mm half-round auxiliary rollers to create
the desired basic cross section. This is
where it all went wrong!
The required cross section is 4mm wide
by 3mm thick, but the half-round rolls give
4×2mm when closed – see photo 9.
No problem, I thought – just open them
to leave a gap of 1mm. This “solution”
created two new problems.A gimmel ring is a
ring with two or three
separate hoops or links
that fi t together to form
one complete ring.
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