The Minting Process

Packaging and Delivery

Circulating coins travel along a conveyor system, where they are counted and placed into small bags or sachets. These small bags are weighed to ensure they contain the correct number of coins, and are then counted into larger bags. The large bags are weighed to ensure that they contain the correct number of small bags.

These large bags are packed into boxes. When full, these boxes are sealed and circulating coins are stored in the Mint’s vaults until delivery trucks are ready to securely collect them and deliver them to banks.

Coining: Collector Coins

The uncirculated coin press has an automatic feed and can make up to 80 coins per minute or 20 000 coins per day.

Proof coins are made in presses which strike with 180-360 tonnes of pressure. Each proof press is manually operated, and the blanks are struck 4-6 times each. Each proof die can strike approximately 250 coins before it has to be replaced.

Uncirculated coins are inspected by staff members who monitor the production conveyor belt as coins leave the press. Any which do not meet standard are removed.

Coining: Circulating Coins

The Mint’s Fitters and Machinists install the dies in the coin presses.  Coin presses can be set up to make different denominations and may make several denominations on the same day.  Blanks are fed through the presses, where they are struck on both sides simultaneously by dies. Dies can strike coins with up to 200 tonnes of pressure, at a rate of up to 650 pieces per minute. Under the pressure of striking, metal particles spread and stretch. This results in a sharper rim, and the edge of the coin taking on any serration in the press’ collar.

Blank Production

Sheets of metal have coin-shaped pieces cut from them. These are known as blanks, which will become coins once they are struck by dies. Blanks are usually round in shape, but an exception is the blank for Australia's 50 cent coin, which is dodecagonal (12 sided).

Blanks are rolled through a specially-shaped groove, which results in a raised edge. The raised metal assists in the coining operation by partially forming the rim so that the dies do not have to displace as much metal.

Dies

The coin design is cut directly into tool steel using a computer-controlled engraving machine, creating what is known as a reduction punch. This process takes up to 24 hours. The reduction punch contains a positive (raised or relief) impression of the complete design of the coin.

Design

The minting process begins with an initial design. Here the Royal Australian Mint’s designers create the image that will eventually be seen on a coin using traditional pencil and paper, a computer, or a tablet.

Afterwards, a three-dimensional model of the design is created using modelling clay, many times larger than the final size. This is then cast in plaster. The coin designer can spend many hours working on this plaster model, refinin the details of the design.

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