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Moderator
 United States
56855 Posts |
I would like to know what the U.S.Mint considers "normal" for the diameter of a Lincoln Cent.Any help appreciated,thank you. John1  |
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Bedrock of the Community
United States
14454 Posts |
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Moderator
 United States
56855 Posts |
Thanks Bryan1315,i know it should be 19mm but they always have a tolerance that is allowed e.g.the weight should be 3.11g for a copper Lincoln and 2.5g for a zincoln and they allow a margin of +/- .13g. I was wondering if they did the same with the diameter +/- 2mm or whatever  John1 Edited by John1
10/22/2008 2:52 pm
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Bedrock of the Community
United States
12437 Posts |
There should not be any diameter variation with modern coins. There are Weight Tolerances because the stock metal sheet could be rolled slightly thick or thin but the diameter of a coin is constrained by the collar(aka "third die") when the coin is struck so the diameter is uniform every time. The collar also imparts reeding to reeded coins. Of course, you could have a collar malfunction and then you wind up with a broadstrike or a partial collar strike(railroad rim) that has a diameter larger than normal but unless incorrect planchets are involved, there is no way to have a smaller diameter. Coins were struck without collars prior to the 1830s and diameters did vary a bit back then. Edited by biokemist6
10/22/2008 3:37 pm
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Moderator
United States
56855 Posts |
biokemist6, I have found a few LMC that measure 19.05mm and 19.07mm and was wondering if they are collectible and if they would have a premium value? John1 P.S. Do you have a photo of a railroad rim you can post? Edited by John1
10/22/2008 3:48 pm
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Pillar of the Community
United Kingdom
1077 Posts |
How on earth did you notice that a coin was 5/100ths of a millimeter too large? Was it a slow day at the office?  |
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Pillar of the Community
United States
3294 Posts |
a difference that small is possible if the temperatures the of the coins differed when measured,.
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Moderator
United States
56855 Posts |
leebreeze, It may sound funny but it felt weired  when I held it between my thumb and forefinger so I asked my nephew to measure it with his digital calipers. John1 |
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Bedrock of the Community
United States
10982 Posts |
19.05mm is the U.S. Mint's nominal diameter. A touch over size is entirely possible. All processes have variation but a 19.10mm cent would be unusual. However when I was a kid, I used to put cents on a railroad track and after the train went by, they were way over 19.1mm in diameter. |
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Bedrock of the Community
United States
20753 Posts |
And don't forget that metal, as well as all materials, expand when heated. Therefore if you measured those on a hot day, in the sun, the metal may have sweeled some. Place them in a freezer and remeasure them. They may well be a lot smaller as metals, like most things, shrink when made cold   Water is one of those exceptions though to many rules. As it freezes it expands for a while then continues to shrink. I suspect that if you heated a cent (penny) in the sun, with a torch, on a hot day it would end up looking like a nickel or quarter. Or a lump of metal. Quote:
How on earth did you notice that a coin was 5/100ths of a millimeter too large?
Was it a slow day at the office? You must really have some great fingers for feel. I couldn't tell the difference in diameters unless it was a few inches. |
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Rest in Peace
United States
9104 Posts |
A penny will get hot and perhaps a bit larger. A cent will bubble up into a blob.
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Replies: 10 / Views: 1,585 |
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Posted 10/22/2008 2:50 pm
