Meaning of minted in coins

Answer 1

"Minting" is the process by which coins are manufactured. It's more complex than you might think, and involves a lot of machinery and special terminology.

Modern mints usually begin with large coils of sheet metal that look like enormous rolls of aluminum foil. These are often supplied by outside manufacturers who make many other kinds of metals, rather than being created by the mint itself. The metal in the rolls is already made to the correct thickness for the coins that will be made from it - there will be rolls for dimes, other rolls for quarters, and so on because each coin is a different thickness.

The metal rolls are fed into huge machines that punch out circles, a lot like cookie cutters. The resulting circles are the blanks from which the final coins will be made. The technical term for the blanks is "planchets". The leftover metal looks like a giant piece of lace or Swiss cheese, and is sent back for recycling. The planchets themselves are fed into what are called "upsetting machines". An upsetting machine doesn't get the blanks angry; what it does is to spin the blanks between rollers that raise, or "upset" a small amount of metal around the edges. That forms the rim that you see on a coin.

The most important step comes next. The blanks are fed into hoppers that release them one at a time into a tube, called the feed tube, that sends each one into the coin press. The blank falls into a holder called a collar. The collar may have smooth edges inside or may have small grooves. A grooved collar will form the ridges, called "reeding" that some coins such as dimes have on their edges. The press has two large metal holders, each one of which holds a die made of extremely hard metal that bears a reverse image of the coin's design. As soon as the planchet lands in the collar, the press brings the 2 dies together and they squeeze the design into the metal of the planchet. The squeezing process makes the metal spread just a tiny bit so the coin's rim is pressed into the collar; if the collar is reeded the ridges are formed as well. The dies then pull apart and the finished coin is ejected into a hopper.

If a coin is supposed to have a lettered edge, like the new $1 pieces, it goes through one last process: the otherwise completed coin goes through another machine sort of like an upsetting machine. The difference is that the coin is now pressed edgewise against a roller that has a reversed version of the edge lettering on it.

All this happens at incredibly high speed - for example, cents are made so quickly that you can't even follow the press as it opens and closes. As you might guess, there's a lot of room for error and mints try very hard to make sure that mistakes don't get out, but it does happen. That's how you find coins without images, with two images, with images that are only partially struck, and so on.

Because you've now seen the various terms that refer to parts of the minting process, be careful of the many mistaken explanations some people give when they discuss coins. You'll often hear about coins being "stamped" or even "printed", or the blanks being called "slugs", but those words are never used by coin people!