How do dies for business strike coins get prepared?

jessewvu

I'm looking at some BU rolls of 2009 cents I've had tucked away for years and noticed what appear to be die polish marks on some. There are several with identical markers but I just don't think they polish dies for business strike coins. So, how do those lines, in various orientation, get on the dies?

Apologies in advance for the newb question. I feel like I should know this.

pursuitofliberty

Just out of curiosity, why don't you think they polish dies for business strike coins? This has been going on since at least the early 19th century.

jessewvu

Seems like a waste of time/effort to me. I suppose I have my answe 🤦‍♂️🥺😥

lilolme

First let me say that I don't know. From there I could see that even if the die is not normally polished that it could be polished or locally so if upon inspection a small flaw is detected. Second the die could have been in use and developed a flaw and it is polished to repair. But again I don't really know.

davewesen

they polish dies to extend use of die, especially after die clash adds design elements in the field

FlyingAl

Modern coinage dies are produced using a single squeeze hubbing press - it forgoes the multiple presses of the 20th and before centuries, and therefore severely decreases the amount of doubled dies and makes those that do exist very very subtle.

I assume that the mint would still polish dies to remove problems such as clashed dies, but it is more likely that they would just retire the die. The modern minting process seems to have fewer die related problems than the earlier years, but I could easily be wrong.

I think that the marks on your coin are related to some sort of die fatigue, but I'm not positive. It doesn't look quite right for die polish.

leothelyon

Polishing the dies creates luster or sometimes proof-like fields. Also removes or smooths out/repairs areas with die erosion or a die clash. I've also recently learned, sandpaper is used to rough up a proof die in preparations to strike business strikes. (See pics of 1965 and 1966 in my collection link below)
The following two coins show both raised and sunken die polish lines that occurred to both the working dies and hubs respectively.
It's also possible a reverse die was used again the following year.

Leo

JBK

@lilolme said:
First let me say that I don't know.....Second the die could have been in use and developed a flaw and it is polished to repair. But again I don't really know.

Liar! You really did know.

Either that or you have good instincts.