How are the current copper/zinc pennies manuafactured?
My inquiring mind wants to know:
Is the raw coil stock a sandwitch of zinc with copper on both sides?
Or are the blanks punched from zinc and copper plated before striking?
Or are the blanks punched from zinc, struck and then copper plated?
The edge of a penny looks like it's "all copper", unlike the edges of other coins, like quarters, where you can see the copper colored center material. So I'm expecting to learn that copper plating is involved.
I tried looking for an answer at the US Mint's web site but didn't find one. They do have a rather nice virtual tour here:
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It was interesting to learn that the sculpted masters for coins are about dinner plate sized and a rather arcane looking pantagraph engraving machine makes a coin size master from which the striking dies are decended.
A slight change of subject. I think the new quarters and nickels suck. The stamping process leave lightly embossed coins, which frankly look as if they were made in India or some third world country. I think the older US coins were better stamped, and frankly better designed. Boo Hiss to the new coins, a pox on their designers, a plague on the people who stamp them out. Brownnsharp
I'm having trouble understanding that because the outside diameter of the penny shows no signs of a zinc center layer.
I just gave the OD of a penny a couple of swipes with one of SWMBO's cardboard fingernail sanders and the white zinc then became visible, over what appeared to be the entire thickness of the rim, minus a VERY thin stripe of copper at the very edge which looks to be only a few thou thick.
So, are you saying that the blanking process somehow smears copper over the OD which stays there during the deburring?
(Leaving to have another look at the US Mint's website.)
Whoops! I should have tried suckering you into betting me $20 on the validity of your answer.
Searching for "plated" got me this from the Horse's mouth*:
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Following is a brief chronology of the metal composition of the cent coin (penny):
The composition was pure copper from 1793 to 1837. * From 1837 to 1857, the cent was made of bronze (95 percent copper, and five percent tin and zinc). * From 1857, the cent was 88 percent copper and 12 percent nickel, giving the coin a whitish appearance. * The cent was again bronze (95 percent copper, and five percent tin and zinc) from 1864 to 1962. (Note: In 1943, the coin's composition was changed to zinc-coated steel. This change was only for the year 1943 and was due to the critical use of copper for the war effort. However, a limited number of copper pennies were minted that year. You can read more about the rare, collectible 1943 copper penny in "What's So Special about the 1943 Copper Penny.") * In 1962, the cent's tin content, which was quite small, was removed. That made the metal composition of the cent 95 percent copper and 5 percent zinc. * The alloy remained 95 percent copper and 5 percent zinc until
1982, when the composition was changed to 97.5 percent zinc and 2.5 percent copper (copper-plated zinc). Cents of both compositions appeared in that year.
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'Twas on this page "The Composition of the Cent":
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Case closed,
Jeff (Who used to work at a place where we made the front ends of horses which were then shipped to Washington DC for final assembly.)
-- Jeffry Wisnia (W1BSV + Brass Rat '57 EE) "Rudeness is the weak man's imitation of strength."
If you would like to find out how thick the copper is, Here is a neat trick. There is a household cleaning product called C.L.R. (it stands for calcium, lime, rust) It's used to remove mineral stains on coffee pots, bathtubs, etc. Take a penny and scuff the edge all the way around so the zinc shows and place in a few oz. of CLR in a small jar for a day or two. The CLR will completely eat the zinc from in between the two copper skins.
Do the same thing, but instead of shaving the entire rim, just nick one small spot, and you end up with a spiffy "hollow penny" - It takes a bit longer though, due to the smaller exposed zinc surface.
I just gave the union 25 cents and have been giving the bank checks every month. What does it mean when the rep from the bank picks up the check for lunch?
"I think this is because of your belief in biological Marxism. As a genetic communist you feel that noticing behavioural patterns relating to race would cause a conflict with your belief in biological Marxism." Big Pete, famous Usenet Racist
I only make bets in beers. I buy a lot of beer. Well that will teach me to answer the wrong question. I think my answer applies to quarters, not pennys.
The way I read this. It implies, they are plated after being struck ?
Someone here was trying to figure out a way to separate out the older "all copper" pennies because with copper up around $3/pound now the metal in them is marginally worth more than one cent and if he could process enough of them he might actually be able to sell the copper and make enough profit to pay for building the sorter and the transportation cost of all those pennies, with some left over for himself.
I wonder if he also thought about the cost of the labor and/or machines involved in rerolling all those zinc/copper pennies so he could turn them back into "folding money" at a bank?
It seemed to me like "A long run for a short slide."
I know what your saying. Last month I purchased a nicely packaged set of five uncirculated 1964 US coins (Penny through half dollar.) as a gag gift for my eldest son's 42nd birthday.
Those coins looked a heck of a lot nicer than today's do.
I put a note on his birthday card mentioning that those five coins would have purchased nearly three gallons of gasoline in the year they were struck.
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