Thought I would share this info with new and old members...some better than basic knowledge that should be helpful. My apologies if it has been posted before. Best of collecting to all! https://en.wikipedia.org/wiki/Coining_(mint) Why do some coins have reeded edges? https://superbeefy.com/why-do-some-coins-have-ridges-around-the-edges/
On that second link the last line about a press that makes 10,000 coins per minute is wrong. Back in 1969 they did have an experimental rotary press for GM that could do 10,000 coins per minute but it was a failure and was never used for production coins. The presses they have now do about 750 coins per minute. The presses they had up until around 2002 did between 80 to 120 coins per minute.
^ When you think about the billions of coins that are pressed you just have to wonder how many of those machines are in use, and, presumably 24/7; looks like 2222.22 hours needed for one machine making 750 coins per minute.
Looking from the gallery down at the floor of the Philadelphia Mint, it's not hard to imagine half a dozen or ten presses striking one denomination at once....you could do a billion coins in a couple weeks that way (figuring 75% uptime).
If you strike say 9 billion coins at one mint, and you are running 24/7/365 That would be 24,657,535 a day or 1,027,397 per hour or 17,123 per minute. Using a press that strikes 750 coins per minute you would need 23 presses. Considering down time for maintenance, die replacement, and the fact they probably don't work 365 days a year you will need a few more presses.
