BooYah
Sep 29 2005, 04:40 AM
hey i was bored the other day,looking through a bunch of pennies i had laying around and noticed that alot of the newer pennies are not the same thickness through out the coin...and im talking about considerable variation. almost wedge shaped...is this something that is a known fact or did i stumble across something here....
LostDutchman
Sep 29 2005, 04:46 AM
Sometimes if the presses are striking coins and the dies aren't exactly parallel or it is striking with a lot of pressure the metal of the planchet will flow to the area with the least pressure making the coins appear thicker on one side then the other...I have noticed this as well and I believe it is common.
BooYah
Sep 29 2005, 05:21 AM
oh..ok that makes sense thanx for the info
cladking
Sep 29 2005, 01:37 PM
You'll see this same thing on the clad coins and the old copper cents. The difference is that with the harder metals it tends to take a bigger toll on the dies and a smaller one on the shape of the coin. The soft zinc is easily deformed on the newer cents.
Conder101
Sep 29 2005, 04:55 PM
Also the thickness of the edge is a function of how strong the strike was. A fully struck coin (such as a proof) has a full thicknss squared off edge all the way around. As the srike pressure decreases so dos the edge thickness. And it isn't an even reductionbecause the planchet may have been closer to on side than the other, or the die faces were not completely parrallel. As the strike pressure decreases you eventually start seeing the bevel left on the planchets by the upsetting mill. (If you look at the edge of a blank planchet you will see that it is either rounded or is a truncated V.) Since they keep trying to go to faster and faster striking they keep lowering relieft and also striking pressure. So it isn't suprising the edges of not striking up well.
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