Want Detailed Info On Modern Coin Production

to CCF.

There are lots of videos abound - I'm sure that someone will come along with a few links for you.

There's plenty of videos on youtube. Give it a go.

This website has some illustrations of a coin press with the various parts labeled, as well as illustrating how some of the typical die alignment errors are made: https://minterrornews.com/features-...sk-dave.html

The illustrations show an older, slower coin press, but the basic function of a modern high-speed coin press is essentially the same; a modern press is typically vertical rather than horizontal, to allow gravity to do a lot of the work in feeding blanks and ejecting coins. But the process is essentially the same.

Dies are large, heavy steel blocks or cylinders with the design of one side of the coin stamped into one end of them. This stamping happens using a hub, which is essentially a die but mirror-reversed so that the design looks like a normal coin, except it's stuck on the end of a steel cylinder. Hubs are in turn made from master dies. This convoluted die-making process ensures that each die is the exact same design, all copies from the original.

Obverse and reverse dies are designed differently, since one (the reverse or hammer die) tends to move much more than the other, this one is usually lighter and smaller. The obverse die moves much less, and is typically larger and heavier. It is thus impossible to "accidentally" get the two mixed up to make double-headed or double-tailed coins - it's literally a square-peg-round-hole problem. Dies also usually have some kind of locking pin to make sure they are inserted into the press "the right way up".

Collar dies are usually in a single piece, essentially a giant ring of hardened steel with the edge design (if any) cut into the inner circle. If collar dies were modular, then there would be a lot more "missing collar piece" errors than we actually see.

A lot of the specialized design and mechanisms of high speed presses in the various mints around the world are trade secrets for those mints, so it may be difficult to find detailed schematics online. The schematics you can find available are the commercially available presses, which usually aren't quite the high-speed devices used in a mass-production mint.

Thanks to Sap and JimmyD for your posts. That diagram and the photos helped tremendously. Now I see that the collar is actually a third part of the coin making process, not just the obverse and reverse dies. I greatly suspected if the collar were 4 pieces, you'd see the gaps where the pieces meet. See about Turk's Heads below. https://www.fenn-torin.com/metal-fo.../turks-heads

My last job was at a non ferrous (copper, beryllium copper, brass, bronze, nickel, nickel silver) wire redraw and rolling mill. We would make square and flat wire from round wire by rolling it in a Turk's Head machine. A Turk's Head has four rolls that can be adjusted to make whatever size is needed. The rolls contact each other so that there is no gap in them. Wire has to be sized correctly to fill the hole in the rolls. If the wire is too big, it will force its way out and cause a fin on the edge of the wire, or crack the carbide rolls. If too small, the corner radius of the square wire will be too big. This flowing of the metal is exactly what is happening in the dies as a coin is produced.

JimmyD, I can understand fins exactly. Thanks for that link. I would never have thought of a fin on a coin though.