Informational - The modern minting process

Discussion in 'US Coins Forum' started by CohibaCris, May 16, 2004.

  1. CohibaCris

    CohibaCris New Member

    The modem minting process is a very complex series of events that takes raw materials and turns them into our coinage we use and collect. I am very interested in the process of minting, so I thought I might share a short description of the minting process for everyone.

    Modern minting was really jump started by the advent of electricity, and high speed presses were made available to produce the staggering number of coins that are being made today. But other aspects of minting have not changed in the US (for the sake of discussion) since the beginning of minting in our country.

    Every new design must start out as an idea that is sculpted into clay, plaster or some other shapeable form. This process is pretty straight forward except the artisan is working in a size about 10-15 times the size of the final coin size.

    Once the design is complete, the plaster model is covered with epoxy to make it hard, and carved into a master hub using a really old machine called a Janvier transfer lathe. Master hubs look just like our coinage, with the image sticking up from the surface of the coin. But master hubs are only the start.

    Master hubs are used to make master dies, that have a depressed image of the coin in the metal. Master dies make working hubs that in turn make the actual striking surface, the working die. These are heated, polished, lathed and inspected to death, because they will be what stikes the coin.

    What about the coin? It starts as mixture of zinc and copper (normally) that is laminated together using pressure and heat into large thin strips of metal that are rolled up. These rolls are huge, and weigh more than a Chevy Suburban. They are placed on a machine and unrolled into the blanking press.

    Remember when you made cookies or biscuits with mom, and you used a ring to cut out cookies from a flat sheet? That is exactly the process used by the mint, only really fast and with metal instead of cookies. The blanks are shot out into a bin, and the webbing left over is shopped up and used to recycle more metal for coins.

    The blanks are heated to soften them up a bit, and are washed and dried. They move onto the upsetting mill, which puts a raised rim around the coin. They ride a conveyer belt to the presses, and are struck using a horizontal press that can strike with up to 60 tons of pressure. Oh yeah, and one press can strike 850 coins a minute (that’s more than 14 coins a second!!!).

    Once they fall out of the press, that final product is our coinage that we circulate today. Coins are periodically inspected by humans, but for the most part are untouched by human hands all the way through the process.

    Hope this was informative, and let me know if you have any questions….
    Cris
    :)
     
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