Did You Know that Coins Start at 12x their Actual Size?

Clay model of a coin at the US Mint in Philadelphia3-D models are sculptured in clay and can be 3-12x the size of the actual coin. There’s a lot of detail on a coin and it’s better to start big, wouldn’t you say? Then it’s turned into a plaster mold, scanned into the computer to create cutting paths (amazing) and then they make the die with positive and negative images. All that art and science and we carry it casually around every day.

A Tour A Day, Makes Paula Happy!

The tour at the U.S. Mint in Philadelphia is wonderful (and significantly better than the Bureau of Engraving in D.C. – there’s no comparison).

No photos are allowed, so you’ll have to contend with the horribly scanned pics I got from the brochure. Sorry. That aside, they do an amazing job of explaining the process, showing before and after of materials and cast (caste?) coins, and incredible views of the production floor.

Protecting the American Dollar, er Cent

It was first debated whether to outsource the U.S. mint to another country who already had facilities and means–why duplicate efforts? But the sage point was made that should there be war or trifles with that country, they would have control over American money.

The Mint Police are one of the oldest Federal forces, and they also protect the gold supply at Fort Knox, which comprises a measly $100 billion in treasury and government assets.

All in a Day’s Work

When the Mint was founded in 1792, workers practically made coins by hand. Horses pulled rollers to flatten materials, scales weighed each coin to make sure it had the right amount of material and was equal its worth. It took three years to produce the first 1 million coins. Today, the Philadelphia mint can produce 1 million coins in 30 minutes; 50 million coins a day.

Oh the Pressure!

Get ready for your next trivia game: before a coin is a coin, it’s called a “planchet” – the blank cutout.

The planchet is a smidge larger than the actual coin, because the edges have to be “reeded” to help the visually impaired differentiate them. Dimes and pennies are similar in size, but only the dime has reeding (the rough edge).

coils of coin material at the US Mint in PhiladelphiaMetal coils that are 1500 feet long (5 football fields) and weigh 6,000 pounds are the raw material for all coins but pennies. Pennies come in pre-cut–they’re already circular!

The metal sheet is fed through a machine that stamps out planchets, a lot like a cookie cutter.

The residual is recycled (Yay).

Blank pennies at the US Mint in Philadelphia

The blanks are then sent to a 1600 degree oven to soften them for stamping. And then smashed with 210 tons of pressure to imprint front and back. That’s a lot of pain to become a coin.


Do you collect coins?

Do you keep them in a jar and then spend once the jar is full? What’s your splurge?

5 Responses


I do collect coins (“kerns”) – fascinating. And I hope “planchet” will be asked today at trivia.

you collect coins? tell me more!


Glad to see this post. I was also disappointed with the Bureau of Engraving tour. Nothing to see except “workers” standing around, looking at the machinery do all the work. And the guides simply herded us to the next station to stand and overlook the floor. Boring!
Only $100 billion at Fort Knox? Hmm…and we’re trillions in debt. You do provide interesting details!


Amazing article!


Your blogging blows my mind!!! Keep it up!!!

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