1974 Philadelphia Mint Cents-Unusual
Tourney64
Posts: 4
I am sorting pennies against a coin comparitor, which compares 2 coins against one another using an electrical impulse and I have gotten 2 - 1974 Philadelphia mint coins that are not sorting as though they are the same metal content as other pre 1982 coins that were 95% copper and 5% zinc. They also don't sort the smae as post 1982 pennies that are 97% zinc and 3% copper. I know that very old wheat pennies had some tin in them.
The coins weigh approximately what they should - 3.11 grams.
Anyone have any ideas?
The coins weigh approximately what they should - 3.11 grams.
Anyone have any ideas?
0
Comments
Are both the coins unc?
<< <i>Both the coins are circulated. Sorting the coins for the copper vs. zinc. People are paying a premium for copper pennies, however I'm just collecting right now. >>
That makes it a lot more interesting since they had different origins yet are the same year.
...And it just happens to be a year that the mint was looking to change compositions.
ttt
That makes it a lot more interesting since they had different origins yet are the same year.
...And it just happens to be a year that the mint was looking to change compositions.
ttt >>
I wonder if one is a small date and one a large date? link
Great reference info Batman23!
Thanks to all who welcomed me to the forum.
I have a hunch this one's going to be difficult to figure out.
Have they been plated?
Is is possible there is a planchet flaw/defect that's
sorting them out?
Why is the sorter saying they are different? Metal Composition?
Because they are the proper weight, I'd say they are not off metals
of any type, and without knowing more about your machine, and just
how they sort/reject, it's tough to know what made them "rejects".....
The machine uses a part from a slot machine called a coin comparitor. There is a sample coin in position in the machine, and when a coin passes thru the slot, an electrical impulse compares the 2 coins. If they are the same in metal structure, then the coin falls into the accept container, and if different, it falls into the reject container. I've sorted over 500,000 coins and had practically 100% accuracy, except these 2 1974 Philadelphia mint pennies. I'm comparing to 1980 penny, which should be the same metal content. When I compare these 2 1974 pennies to older wheat pennies (i.e. 1928 D), they indicate as a match, but other 1974 pennies do not. The older wheat pennies have a small amount of tin in them, and I suspect some of the 1974 Philadelphia mint pennies may also.