Coin design experts, a question.

Dozer D

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Question on the reeded edges of coins., and if I remember reading up on my coinage history, was that reeded edges were put on silver coins so as to curtail and help detect the filing of the edges of silver on the coins. Otherwise it would be easily detected as being tampered with, and not getting the full measured weight of so said silver.

Are the number of the grooved edges on our coins the same from one coin generation to the next? Example: are there the same number of grooves on a barber dime, vs the same # to a Mercury dime, vs the same # to a Roosevelt?

Ditto on quarters & halves.
Are there the same number of grooves on a Std Lib half, vs Benjamin, vs Kennedy all the same.
Carrying same ? of Canadian coinage vs US, are there the same # of grooves between the two countries on dimes qtrs halves?
The last ultimate question, is there the same number of grooves on a Rosie dime to those of a Kennedy half, just that they are bigger on the half dollar.
And one final ? is at what point in the coin stamping process is the REEDED EDGE put on? Your comments, and enlightenment to others who have the same ? if any., thanks coinage experts., DozerD
 

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port ewen ace

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edge is created by the collar-- Frank & Enamel---- now it's your turn:laughing9:
 

Diver_Down

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Whole bunch of questions so I will likely leave one out. As mentioned above, the reeds are indeed imparted by the collar. Each denomination has specifications - weight, diameter, thickness, and reed count. So when you ask if a Barber has the same number of reeds as the Mercury dime, the answer is yes. The reed count obviously changes from denomination to denomination. The origin of reeds was indeed due to unscrupulous persons shaving the edge of coins.
 

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Dozer D

Dozer D

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Thanks Diver, that's a start, good info to know.
 

Mackaydon

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How do the reed (groves) get there:
Those small grooves are usually added during the striking process. Coin dies produce the obverse and the reverse of the coin. To hold the coin securely during the striking process, a metal collar that is the exact diameter of the coin is placed in between the two coin dies. A planchet is placed on top of the anvil die and held securely by the collar.
The collar has a series of small grooves carved into it around the entire circumference. When the planchet is struck at enormous pressure, the metal in the coin tries to expand out the side but is held in place by the collar. The tiny grooves on the collar are now transferred to the edge of the coin.​

I'm still counting the grooves so I don't have that answer.
Don.....
 

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Dozer D

Dozer D

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I wish that there was a super slow motion video of how coins are stamped at the mint. I'll try for a video later, start to finish I hope.
 

PetesPockets55

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Good questions and replies.
Yes there are three dies: ... Obverse, Reverse and Collar (With the collar imparting the reeds on the edge as the planchet expands to fill the design.)

If memory serves me correctly there are varieties (can't remember the denominations) where the number of reeds changed in a particular year. I think it had to do with the width of the reeds being slightly wider/thinner which affected the number.
 

Diver_Down

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once the reed is punched thru the coin, do they recycle the silver shavings?

just a thought,, thanks, marion

There is no metal loss. The blank planchet will weigh the same as the minted coin. The immense pressure between the dies and collar cause the metal to flow in the devices resulting in the design. That pertains not just to the obverse/reverse, but also the edge.
 

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