Struckthrough Die Cap?

[Dick]

Ed, that is a very good "picture" of what happens athat instant! Yes it would be very interesting. Now imagine that you can see the same thiing happenong, but without the planchet being there! Then everyone would get to "rumble"!
Going back to your explanation of the "Bay on the neck" scenario. I mentally see the "prison coin, and notice the bays, reversed on the obverse and readily see how it happens, but the "neck (bay) just doesn't seem to fit, because of the depth of the engraving. Until you mentioned the shallowness of the engraving, it was hard to mentally picture how it could be, then considering the shallowness involved, I am even more surprised at the 3-dimensional appearance it gives. We live so much in the 3-dimensional world, that it is hard to conform to the 2-dimension view, at times.
Dick

[mikediamond]

The die must give a little, as it shows some resilience when you clack two dies together. They bounce off each other. However, we're talking extremely small movements.

Die convexity insures that the center of the design strikes up properly and it pushes some coin metal outwards, insuring that enough metal rises up to fill up the gutter in the die face that corresponds to the design rim. Modern dies show very little convexity. It was much more exaggerated before the 1990s.

[nightshade]

so mike if you find a coin after 1990 that shows the same convexity as same a 1940 penny should that be a keeper or a tosser <-- as in very insane

[mikediamond]

[nightshade]

hehe i was giving you a hard time yet i guess that means if i do find one like that i should keep it

[mikediamond]

[eagames]

For the most part the convex surface is on the die not the coin.

For example if you held a coin against the die that struck it the only area that might touch is the center. While being struck it is touching on the entire surface. Metal confined in a collar getting hit under high pressure acts like a spring.

[mikediamond]

[Dick]

nightshade, I'll add my 2 cents, by sayibg the slightly concave surface og the planchet is due to the blank, having been thru the "up-set mill", which is whar makes the "rims". Not the most clear explanation, but I think you follow what I mean.

Dick

[eagames]

Agree with everyone, the upset planchet and coin designs are slightly convex. By spring I mean it flexes more than the die which is harder. The presses use so much pressure everything has to flex a bit.

Sort of amazing, on TV they showed the presses and the coins shoot through very fast. No wonder a few mistakes get through.

[Dick]

To the collectors pleasure!
Dick

[marklar]

So did i find a secret treasure or is this common? what's it worth other than 1/100th of a dollar?

[Dick]

markler, IMHO, the coin is a KEEPER. There might be other opinions,but I definitely would keep it foe severasl reasons. Thety are niot that common, it has to be an error of some kind, and the explanations given above indicate that. So Keeper? Yes. Id you don't want it, I'll PM you with my address!