Someone correct me if I am wrong, but it sure appears that the silver proof Ikes are bigger (thicker) than the clad Ikes. I ordered some proof Ikes (72-s and a 76-s) for my 7070 and was surprised at the thickness. I compared them to the circulated clad Ikes I have and they are a full mm thicker, similar to the thickness of a Peace dollar. I've always viewed Ikes as second rate silver dollars (because I've only held the clad ones), but this discovery puts them in a different light for me. :hatch: I might have to start collecting the silver proofs. :hail:
A couple of thoughts: 1) Could circulation do anything to cause this? 2) Could the fast, mass production of the clad issues produce a slightly different planchet than the more carefully produced collector silver issues?
I believe it is only thicker at the rim. The proofs have rims that are square-like....while the business strikes are rounded slightly giving the appearance of a thinner coin. I noticed this on Half Dollars as well. At least that is my explanation.
You are not crazy! Clad Ikes weigh 22.68 g Silver Ikes wiegh 24.59 g So silver Ikes are about 10% heavier than their clad counterparts
The thickness of a struck coin is dependent of the quality of the striking. The better the strike the more fully the rims are struck up and the thicker the edge. Proofs are struck TWICE at a higher pressure than the business strikes which are only struck once, so the rims are very high, fully struck and squared off. The silver composition is also softer than the coppernickel clad so it strikes up better. For this reason they seem to be thicker than the business strikes. That has nothing to do with the thickness though. The planchets for both are the same diameter and thickness before they are struck. The silver proofs are 10% heavier because silver is denser than copper or nickel.
Speaking of proof Ike's, I bought about 5 Ike's in the brown slip-out packaging from my local B&M about 5 years ago. I went to inspect them closely when I got home, and one of them had a serious raised rim, I mean about 1/8 of an inch above the obverse. What is that called? and does it bring a premium? any help is appeciated, thanks.
You mean to tell me that you didn't bury it with everything else? An 1/8" is quite significant and it would be surprizing to hear of a capped die error being put in a brown box. Got a pic of this coin?
I think an 1/8 of an inch might just be an over dramatization since the plastic cases these coins came in is only 5/16 of an inch thick. An 1/8th of an inch ( 2/16 ) would not even fit into the packaging. Photo's would be appreciated.
<<That has nothing to do with the thickness though. The planchets for both are the same diameter and thickness before they are struck. The silver proofs are 10% heavier because silver is denser than copper or nickel.>> There is more going on here. A clad dollar is the weight of two clad halves. A silver clad dollar is about 107% the weight of two clad silver halves preserving the ratio of 1853. So I believe the silver dollar clad planchets could be thicker than the cupro-nickell clad ones.
No there isn't. The specific gravity of the 40% silver composition is 107% of that of the copper nickel clad composition. 9.53 vs 8.92 So if you had two planchets of the exact same size, the 40% silver one would weight 7% more than the coppernickel clad one. Because silver is denser than copper or nickel.
Amazing coincidence! And at this point in history, your ratio is probably more meaningful than mine. I will play with these numbers some more when I get back to my reference books.
Assuming the numbers given in this thread are right, I get Density 9.53/8.92 = 1.068 Ike Dollar weights 24.59/22.68 = 1.084 SSD/SS weights 26.729/25 = 1.0692 Slightly thicker planchets are in the running again. Density increase does not completely offset the weight difference.
But weight tolerances for the planchets are greater than the slight differences in the 1.069 to 1.084 figures. The copper nickel clad dollar can range from 21.773 to 23.587 and the silver clad can range from 23.608 to 25.576 So the variation of CuNi/Ag coins within standard tolerances can vary from 1.0009 to 1.174 So since we know a silver planchet is 7% heavier than a CuNi planchet of the exact same size, just how much thicker would it have to be to weigh say 10% more? Now the surface area of the face of an Ike planchet is 11.40 square cm. The volume at 24.592 grams is 2.58 cubic cm so the thickness of the planchet would be .226 cm or 2.26 mm. So if it was 10% heavier than a CuNi clad dollar it would weigh 24.948 grams, would contain 2.62 cubic cm and would be 2.29 mm thick or .03 mm thicker or about 1/1000 of an inch thicker. This is not something you are going to be able to see and judge by eye. Even at the MAXIMUM weigh allowed by tolerance, the planchet would only be 2.35 mm or .09 mm thicker or 4/1000th's of an inch. This is about the average diameter of a human hair.
The proofs are a little more difficult to get into an album. Reason being is they are struck twice, whereas business strikes were struck only once. Also silver is more "soft" allowing for full detailed strikes, fuller rims ect. The clad Ike's were a beast of a coin for the mints to produce.
