1964 D Jefferson Nickel Obverse Rim

It's doubtful that the upset mill can generate a thin apron along the perimeter of a planchet. Narrow spacing in the upset mill only generates a tall proto-rim but no apron. It is probably some other piece of machinery. Goodness knows, planchets have to travel through many pieces of equipment before they arrive in the striking chamber.

I've seen four other cents with struck-in aprons, indicating that this is not a one-of event.

Now that I think about it, it was an off center coin I saw with this effect (or similar). It showed on the unstruck portion of the planchet. Was this a coin that you wrote about Mike? If so what were your determinations? The effect on my friends planchet is entirely different. I mixed it up with the Off Center I saw somewhere.

Thanks Mike! You positioned the link to that article so far down from the body of your post that it appeared to be a part of a signature and I never saw it. Very interesting article. In any event, maybe I missed it, but did you get the diameter of the so-called " Dryer Coin"? I'm interested in following this effect further in trying to learn more about the causes. On the Off Center, this one is plain strange. Do you own the coin or have larger images I can see? I have an idea but really need to see the surfaces in far greater detail.