From
the development of powerful cold metal presses, to the casting of molten
metal and reducing machine use, the process for producing medals, medallions,
coins, tokens and plaques has not changed significantly for over a hundred
years. It is a traditional industry developed in Europe as an art-form.
It is said to have begun in 1438 in Renaissance Italy by Pisanello, formally
known as Antonio di Puccio Pisano a painter and sculptor. He first cast
a medal of Byzantine Emperor John VIII. The medal is round, high relief
and strongly resembles a coin in both design and shape.
Medals can
be struck in copper, bronze alloys or precious metals such as silver and
gold. Other metals can be considered although dependent upon their minting
abililities. Sizes can vary from 10mm up to 100mm and although are usually
round do not necessarily restricted to round.

Ergonomics
society of Australia medal
Medals,
medallions, coins, tokens and plaques all have the same general process
in production and take from 3 weeks to as much as 8 weeks to produce.
Delivery times for medals are from 3 to 6 weeks from design approval.
Design
– 1-2 weeks
Designs are developed according to the customers brief in consultation
with an artist specialised in minted products. The designs are prepared
first as concept drawings then finished on computer. Upon approval by
the customer the design then proceeds to the sculptor to sculpt the plaster
model. Decisions such as finished size, metal and type of surface finish
need to be established at this stage although some flexibility does exist.

Artist
working on medal designs
Sculpting
of the plaster model – 1-3 weeks
The sculptor works from the design first in plasticine or clay on a sheet
of glass to build up the image of the design. This is called bas-relief
sculpture. A plaster is then cast from the plasticine and then using special
hand tools the sculptor further works the plaster model until complete.
The sculpting process takes around 1 to 3 weeks depending upon the complexity
of the design. One plaster model is required for each side of a medal.

Sculptor
working on a plaster model
From the
plaster model a silicone rubber mold is cast then an epoxy resin model
is cast from the rubber mold. This epoxy resin model is a copy of the
plaster model only in a more durable medium required for the next stage.
Reducing
Machine - 1week
The reducing machine is a unique tracing/engraving machine used specifically
by the minting industry. The epoxy resin model is traced by the reducing
machine over a period of several days cutting the design into special
tool steel, first with a roughing cut and then a finer finishing cut to
capture the detail that the sculptor has skilfully sculpted into the model.
The copied design cut into steel is known as the reduction punch or hob.

The
reducing machine
The reduction
punch is checked by a specialist hand engraver to ensure that there are
no imperfections from the tracing and cutting process by the reducing
machine. This task is performed under a microscope and requires great
skill in using specialist hand tools. Once the engraver is satisfied with
the finish the reduction punch is heat treated so that the steel is appropriately
hardened for the next process known as hobbing.

Engraver
working on master tooling for coins
Master
and Production Tooling 1-3 weeks
The hardened reduction punch is then placed into a hydraulic press for
the hobbing process. The reduction punch is pressed into another piece
of tool steel at incredible pressures of up to 800 tonnes to create a
negative impression of the design. This may take several attempts to achieve
the full size and detail of the medal or coin design with an annealing
(softening) of the steel between each pressing as it work hardens as pressure
is applied.
This negative
is called the die. The die is used to strike the medals after it has been
machined in a lathe and heat treated (hardened), otherwise known as the
production die.
 
Production
dies
For coins
this die becomes the master die for safety and security purposes and the
hobbing process is then repeated two more times. The first time to produce
an additional positive image similar to the reduction punch although of
better quality. This is called the working hob. The second and final time
to produce the production dies or working dies. The engraver works on
each stage again ensuring that there are no imperfections in the design.
Pressing
of Medals
Two production dies are prepared for fitting into a hydraulic press, one
for the obverse and the other for the reverse of the medal. Appropriate
to the metal required for the finished medals or coins blanks are punched
from sheets of the metal, copper, bronze alloys, silver or gold. The blanks
are placed between the dies in the press and contained by a collar. Then
squeezed at pressures of around 300 to 600 tonnes. Depending upon the
height of the relief in the design the medal may have to be struck several
times with intermediate anneals (heating to soften) to achieve the full
detail of relief.

Annealing
high relief medals for a second strike
Finishing
of Medals
The medals are then finished accordingly. Some may have a patina applied
to give an antique appearance and also to protect it from oxygen within
the atmosphere or a frosted, satin finish. Some may be electroplated with
gold or silver some may have a proof type finish which is a polished appearance
straight from the dies during the pressing process.

Finishing
medals
Occasionally
medals may have fittings applied to hang from ribbons to be worn around
the recipients neck or pinned to their lapel.
The medals
are then packed into their presentation boxes. Presentation boxes come
in a variety of differing styles from soft-bodied leather style cases
to custom made wooden boxes.
 
The
Ergonomics Society of Australia Medal showing obverse and reverse |