Pic Of 1997/96 R. Dime Over Mint Mark Weird!

Quote:
Mintmarks were added to each individual working die by hand until 1990. This allowed each individual die to sport its own unique problems with how the mintmark was applied. This is where repunched and over mintmarks happen. In 1990 they went to a new process where the mintmark was included in the master die making process, which removed the need to punch the mintmark into individual dies. The process of adding the mintmark to the master die was watched VERY closely so doubling would not occur, and this effectively removed any future chance of repunched mintmarks and over mintmarks.

Over dates and repunched dates operated in much the same way, but ended in the very early 1900s when the entire date was included in the process BEFORE the working die stage, so that every working die was hubbed with the entire date intact. Repunched dates and over dates occurred because the large design reduced to the small design did not have the entire date on it. It was used from year to year in order to save money. At the end of the die making process, you could see hundreds of dies without a complete date. Punches were used to complete the date on each die by hand. Because the human hand was involved, these punches could bounce, be out of place, etc. allowing for wrong digits, doubled digits, etc. Up until some time in the late 1800s the date was punched into individual dies - thus allowing room for fault in punching the digits, thus repunched and over dates.

Beginning with the 20th century types, the date was included in its entirety somewhere in the hubbing process so that by the time the working dies were hubbed, the entire date was placed into the die by machine, not by hand. This removed all possibility for repunching date digits, henceforth removing the possibility of repunched and over dates.