Rim finning on open collar Bust Half

VanHalen

Can anyone explain why the rims on this open collar Bust half appear finned? It is in a straight graded PCGS holder. Thank you.

jacrispies

kaz

Maybe the edge was raised in the milling machine used at the time, and the dies were so worn that the extra metal wasn't forced into the recesses for the dentils, leaving the sharp edge?

VanHalen

@kaz said:
Maybe the edge was raised in the milling machine used at the time, and the dies were so worn that the extra metal wasn't forced into the recesses for the dentils, leaving the sharp edge?

Thank you. I suspected it was from the edge lettering process. I would like to hear other input.

lilolme

@VanHalen said:

@kaz said:
Maybe the edge was raised in the milling machine used at the time, and the dies were so worn that the extra metal wasn't forced into the recesses for the dentils, leaving the sharp edge?

Thank you. I suspected it was from the edge lettering process. I would like to hear other input.

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Here is a link to an NNP article by @BustDMs that explains the Castaing machine. (it opens a couple pages into article)

https://nnp.wustl.edu/library/book/568039?page=34

I can't speak to the OP coin.

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I looked through the coinfacts more images for 1836 and there are some with some limited rim areas. But I don't see anything like the OP. They have the deteriorated die strike details (missing dentils...). or some more off center appearance. Here is one but again not like the OP.

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https://www.pcgs.com/coinfacts/coin/1836-50c-lettered-edge/images/6169

VanHalen

Thanks for the input thus far. I added the reverse image to the first post. I've seen similar rims on other open collar strikes but this one is really pronounced. A member suggested the rims are damaged even though it's in a straight holder.

PerryHall

The die is slightly narrower than the planchet. What you are seeing is the outer edge of the planchet that wasn't struck by the die. You would expect this edge area to be slightly raised above the adjacent planchet area that was compressed by the die.

4Redisin

Thanks for the link about edge letters! I always wondered what came first, the letters or the strike. As far as I know, there are only two things that can cause this and they have both be mentioned already. Either metal squeezed out at the edges during striking (were these coins struck on a screw press?) or the edge was spooned or repaired with the alteration going all the way around the coin so one area affected did not appear different. I have not seen many Bust coins as I collect copper so I'm probably wrong because PCGS graders are the experts. Anyway, the evenness and sharpness of the fin suggests an alteration. Perhaps knowing the grade assigned would tell if it was net graded or not.

VanHalen

@4Redisin said:
Thanks for the link about edge letters! I always wondered what came first, the letters or the strike. As far as I know, there are only two things that can cause this and they have both be mentioned already. Either metal squeezed out at the edges during striking (were these coins struck on a screw press?) or the edge was spooned or repaired with the alteration going all the way around the coin so one area affected did not appear different. I have not seen many Bust coins as I collect copper so I'm probably wrong because PCGS graders are the experts. Anyway, the evenness and sharpness of the fin suggests an alteration. Perhaps knowing the grade assigned would tell if it was net graded or not.

May have been netted. Certainly a strong XF. I believe the "finning" was imparted through the edge lettering process but I'm no expert. Thanks for all the input thus far!