A modern press used at Philly or Denver is doing multiple strikes PER SECOND! The sound is like a machine gun.
The slow vertical presses are still used, but for numismatic coins and medals, not for production of pocket change stuff. By reading between the lines of Mint reports, it appears that the S-mint so-called "circulation quality" ATB quarters are being struck on a vertical press that was originally doing proof coins. The 5-ounce "pucks" require their own dedicated presses, made in either Germany or Switzerland. Although I'm willing to bet they're now also used for the gold medals which they present to honorees.
Think about it. If they introduced “oil” into the process any resulting copper coin would soon be a small blue disk would it not? Just asking.
Not exactly the same, but has similarities from thread https://www.cointalk.com/threads/1868-nickel-error.281484/#post-2508079 where some are calling this "die fatigue spikes", though not a die deterioration issue (as in excessive use of the die causing fatigue). Th OP has this, could it be the same issue??? In other words, is this a case of extreme and very fast developing metal fatigue issues with a particular die? and this is similar from the coincommunity link I shared, an example of a dime and of course, my quarter
I don't but I know I have read stuff elsewhere, but I'm not yet sure exactly where. I have also seen them live in operation. While this picture shows a one-at-a-time horizontal press, it is my recollection that the production machines at Philly and/or Denver strike perhaps six or so coins at a time, with multiple pairs of dies arranged in a circle.
thanks for the info. Much appreciated. I will search the Internet and try and find more on this process.