What Does RPD, MPD And OD Mean? Part One:

Finally in the right spot! Thanks guys!

Awesomely helpful.

Small correction on the matter of the early overdates. With the exception of the 1806/5 quarter and half dollar NO overdated die was used before it was overdated. (There are no coins known struck from a die before it was overdated with the exception of those 1806/5 dies.) In every case they were an unused and unhardened die that was left over at the end of the year. The new digit was punched in and then the die was hardened and used. Hardening of dies was a very chancy thing and dies frequently failed and cracked during the hardening process. So if you had a usable hardened die left at the end of the year you weren't going to risk softening it, adding additional stresses by overdating it and then run the risk of rehardening it. You just used it as it already was. But with an unhardened, unused die you had nothing to lose so you overdated it and hardened it. Dies made close to the end of the year frequently were not hardened until just before use for that reason. If production dropped and the die wasn't needed it could be overdated and used the next year. Eventually they stopped punching in the last digit until right before hardening. That would eliminate the need for most overdating.

For a second I thought this was coop asking a question about a coin being an error, until I realized that it's not....hahah.

Well this is always a community effort. One helps share what they know on the subject to assist the information presented. Even the experts are still learning after years of study.

Wow. I'm just amazed at the depth of knowledge here...

Thank you. Now I understand RPD, MPD, & OD. When I first read them on a different thread, they were a foreign language to me. Hence this thread...

Great information. Just wish Album manufacturers would never put those in their products.