D Over S And Other Mint Goofs—how Did They Happen?

The errors you've discussed were made on the die, not on the coin. The die errors only show up on the coins after they've been minted.

In the past, the mints shared dies amongst themselves. After Denver finished minting it's allotment of a coin, they would ship their dies to San Francisco for their use.

These dies were already stamped with a D, so the die would be polished and then re-stapmed with an S. Sometimes the polishing would not remove enough of the original D and the resulting coins minted with the die would show both the D and the S.

Same thing with the dates basically. They would polish the earlier date off and restamp the die with a new date and if they didn't polish off the old date completely you would end up with an overdate.

The overdates went away when they stopped stamping dates into the dies and the OMM (over mintmarks) went away when they stopped sharing dies, sometime in the 1950's.

In the search box, top left, type in 'causes of errors' .

Your results will give you many results for different error types. This search box is great for endless types of inquiries. Good luck with your ongoing education and understanding.

Thank you thank you! I don't collect error coins per se, though my first buy was a 1938 DD Buffalo nickel. I'm just enough of a geek to go looking for info on how these kinds of things work, when I have the time.

Unfortunately most of it is wrong.



Correct! Until 1997 all the dies were made at Philadelphia and they did not have any mintmarks. When a mint ordered more dies a group of unhardened dies of the proper date would be selected and the mintmark punched into them. Then they would be hardened and shipped out. Sometimes the guy might pick up the wrong punch and put the wrong mintmark in the die. now he has three options: 1 they can scrap the die. 2 they can hold the die and wait for the other mint to order more dies and include it in that shipment. 3 they can punch the correct mintmark in the die over the wrong one.

Number 2 would be the preferred option, but if it is near the end of the year it may not be likely the other mint will order more dies. Usually the option chosen in that case would be to scrap the die. But maybe the guy is in trouble for having messed up too many dies already, so they just overpunch with the correct mintmark. There are a few cases of an over mintmark being done deliberately. In 1899 the CC mint was closed as an assay office and some dollar rev dies were shipped back to Philadelphia. These were repunched with an O and shipped to New Orleans. In 1938 if was decided that only Denver would be striking the last year of the Buffalo nickel, but they still had a could of S mintmarked dies on hand. So the over punched them with a D and shipped them to Denver. The same thing happened in 1955. San Francisco was being closed down but they still had so S mintmarked rev dies. So they punched something like 12 different dies with a D over the S and shipped them to Denver.



They aren't. The overdate is in the die, it isn't something they do to the coin. In the early years of the mint dies were made in batches and the last thing done to them before hardening was to punch in the date. Well at the end of the year if production had slowed you might have an unhardened fully dated die still on hand.

Well in those early years die steel was expensive and hard to come by, so you didn't want to waste it. If a hardened dated die was still good they would just continue using it into the next year (even though that was against the law). If the die hadn't been hardened, the date for the following year would be punched in and it would be used. As an example, at the end of 1798 the mint had 8 cent dies on hand two fully dated 1798 and six just dated 179_. In 1799 one of the fully dated dies was repunched with a 9 creating a 1799/8 and one of the 179_ dies was finished with a 9. But 1799 was a low mintage year and at the start of 1800 there were still six dies on hand left from 1798, one dated 1798 and five 179_. These were all overdated with 1800, one 1800/1798 and five 1800/179. Those five dies were used to make 11 different die marriage combinations.

After 1907 the dates were in the hubs used to make the dies and were not punched in by hand and there have been I think only six overdates since then and they are actually doubled dies. At the time it took more than one squeezing of the hub into the die to fully bring up the design. Between hubbings the die would be annealed (heat treated to soften it) and then brought back an hubbed again. If it was paired up with a different hub than the first time you can get either distorted hub doubling, or design hub doubling. If the die is hubbed with a hub with one date and then hubbed with one with a different date you have design hub doubling and an overdate as both dates will show. This happened in 1909 on one double eagle die, in 1918 on a Buffalo nickel die and a Standing quarter die, in 1942 on two different dime dies, and in 1943 on a nickel die.

Thank you so much, Conder! I missed your addition to the topic until this am, but it's great info!