The U.S. Mint’s Overview of the Coin Minting Process makes it look easy. But that’s what professionals do: they make amazing feats look easy to us curious on-lookers. But just how does the World’s largest coin minting organization pump out tens of Billions of wonderfully collectible coins each year? Read on and find out.
The first element required to properly stamp a modern coin design is a master die. Actually many master dies will be required because they can and do wear out over time. The United States Mint’s brilliant artists must first go through the incredible process of turning original artwork into a stamping die which has the reverse image of the coin design. These sometimes unsung heroes are the Mint’s sculptors and engravers and are the Masters of Art Behind Collectible Coins.
If you’ve ever been involved with any artistic work, you know that the process is rarely simply going from vision to final piece of art. The artwork behind America’s coins go through several evolutions. The original design goes from computer or paper to clay. Then from clay to plaster. Provided that the plaster reproduction meets the Mint’s exacting standards, machinery and software take over. The large plaster design is read by software and reproduced onto steel reduction hubs. These now coin-sized reduction hubs are used to create the master dies. The master dies have all the features of the original engraved and sculpted artwork–but in reverse. That is, those areas that were recessed are now raised…and vice-versa. This is so coin blanks can be stamped, or formed into the recessed areas of the die and pressed by the raised parts. Quality Control is critical here as even the slightest flaw could mean the waste of millions of coins.
Now that we have dies, we need something to stamp them with. The U.S. Mint purchases pre-made coils of metal meeting the specific composition of a given coin to be produced. These 1,500 foot coils of metal are run through a puncher which punches out coin blanks. What remains of the metal coil is now riddled with holes and resembles a Web. The Mint recycles this webbing into reusable metal from which future coins can be made. After a heating, cooling, and washing process the coin blanks are somewhat soft and malleable. The coin blanks are fed through an upsetting machine which progressively squeezes the coin blank’s sides to produce ridged edges. These raised edges are not only a design feature, they also accommodate the outer rim of the master dies.
The master dies have waited patiently and are now ready to pound some metal into the World’s most beautiful currency. Coins are being stamped at a rate of up to 45,000 per hour at this stage and mistakes can occur. Inspectors meticulously scrutinize newly struck coins, rejecting those that are less than perfect into the dreaded waffler. The waffler brutally defaces the error coins so they are beyond recognition as legitimate currency. The waffled coins, like the webbing before, is also recycled for future coin production. Those coins that pass countless inspections are counted, bagged, and eventually shipped off to Banks requesting them. And a lucky few of these American masterpieces make their way into your coin collection!
See these videos to see the process in action:
How Coins are Made…for Kids – U.S. Mint
Modern Marvels – Coin Production – History Channel