1943 cent composition
Toad1000
Posts: 19
Does anyone know what the composition of the 1943 steel cent is?
Everything I find on the net says either 100% steel (which doesn't account for the zinc), or zinc-coated steel (which doesn't tell me the proportions).
The current cents show as 99.2% zinc and 0.8% copper. I was just wondering if anyone had data on the 1943 cents.
And to be even more nerdy, does anyone know what the actual composition of the steel was? Every other US coin can be broken down into an actual element (silver, copper, gold, nickel, tin) So how much iron and how much carbon?
Thanks.
Everything I find on the net says either 100% steel (which doesn't account for the zinc), or zinc-coated steel (which doesn't tell me the proportions).
The current cents show as 99.2% zinc and 0.8% copper. I was just wondering if anyone had data on the 1943 cents.
And to be even more nerdy, does anyone know what the actual composition of the steel was? Every other US coin can be broken down into an actual element (silver, copper, gold, nickel, tin) So how much iron and how much carbon?
Thanks.
Convinced myself, I seek not to convince.
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Welcome to the boards.
You wouldn't believe how long it took to get him to sit still for this.
Hope that helps Toad1000 - and BTW - welcome to the boards!
“In matters of style, swim with the current; in matters of principle, stand like a rock." - Thomas Jefferson
My digital cameo album 1950-64 Cameos - take a look!
2%? That sounds about right.
In both cases the steel strip was rolled to the correct thickness then coated with molten zinc. The strip was rolled again to remove imperfections and then blanks cut. Upsetting to form planchets was done in the normal manner.
Letters from the San Francisco and Philadelphia Mints state that they had a lot of problems with planchet hardness in the beginning, but this problem was solved in a couple of months. A more difficult problem was swelling and rusting due to the blanks being stored in railway cars when the mints lacked inside storage space. This largely affected purchased blanks.
Nearly everyone from the President on down hated the steel cents and as soon as they could get their hands on old shell cases, the switch was made to 95% Cu, 5% Zn and a trace of tin.
<< <i>By my rough calculations, the weight of the zinc plating on a '43 cent is about .056 grams. The total weight of the steel cent is 2.7 grams so the plating is about 2% of the total weight.
Hope that helps Toad1000 - and BTW - welcome to the boards! >>
Wait a minute. Zinc and copper are almost identical weight, and everyone seems to think the zinc coating on 1943 pennies is so thin as to be non-existant. So if the current copper coated cents are only 0.8% of the total composition - then how did you come up with 2% for the zinc coated steel? Just wondering how you cam eto your numbers, I wouldn't have the first clue on how to calculate it myself.
<< <i>Zinc is definitely thinner than the copper.. no doubt. >>
Okay, so we're probably looking at 0.5% zinc or maybe even half of that for the total composition? No wonder they rusted.
<< <i>Does anyone know what the composition of the 1943 steel cent is?
Everything I find on the net says either 100% steel (which doesn't account for the zinc), or zinc-coated steel (which doesn't tell me the proportions).
The current cents show as 99.2% zinc and 0.8% copper. I was just wondering if anyone had data on the 1943 cents.
And to be even more nerdy, does anyone know what the actual composition of the steel was? Every other US coin can be broken down into an actual element (silver, copper, gold, nickel, tin) So how much iron and how much carbon?
Thanks. >>
The specifications for modern (1982-date) cents call for a small amount of copper mixed into the zinc to allow the planchet manufacturers to melt down and recycle reject planchets without bothering to refine the copper plating back out before casting the zinc into new ingots. This is an eminently logical procedure.
I have yet to see a 1982- cent with the copper plating worn through in normal circulation. However, you see a lot of slider steel cents in collections where just a little rub on the high points was enough to wear through the zinc plating and allow the steel underneath to discolor and/or rust. I therefore conclude that the zinc plating was very thin.
TD
<< <i>
<< <i>By my rough calculations, the weight of the zinc plating on a '43 cent is about .056 grams. The total weight of the steel cent is 2.7 grams so the plating is about 2% of the total weight.
Hope that helps Toad1000 - and BTW - welcome to the boards! >>
Wait a minute. Zinc and copper are almost identical weight, and everyone seems to think the zinc coating on 1943 pennies is so thin as to be non-existant. So if the current copper coated cents are only 0.8% of the total composition - then how did you come up with 2% for the zinc coated steel? Just wondering how you cam eto your numbers, I wouldn't have the first clue on how to calculate it myself. >>
Well, first of all, the density of pure zinc is 7.14 grams/cc while the density of pure copper is 8.92 grams/cc. So zinc is about 20% lighter than copper.
For the zinc plated steel cents, I calculated an approximate surface area and multiplied that by the assumed thickness of 0.0005 inches. This thickness is very typical of zinc plated items. As noted above, the zinc was not applied by a plating process, but more of a galvanizing process, so the thickness may be different. At any rate, the approximate amount of zinc on a steel cent is about .056 grams or 2%.
For a copper plated cent, the Redbook states that the zinc core is 99.2% zinc and 0.8% copper. This would mean the core contains about .02 grams of copper because the weight of the cent is 2.5 grams. But you now have to add the weight of the copper plating to the copper contained in the core. Using the same method as the zinc cent, the approximate weight of copper in the plating is .07 grams. So the total copper is 0.07 + 0.02 = 0.09 grams (or about 3.6%)
Note: Keep in mind that copper is denser than iron as well. Iron is only 7.87 grams/cc. So iron is 12% lighter than copper.
“In matters of style, swim with the current; in matters of principle, stand like a rock." - Thomas Jefferson
My digital cameo album 1950-64 Cameos - take a look!
There might have been some variation in the thickness of the
galvanizing layer. Steel strip is heated and run through a bath
of molten zinc. If the steel or the zinc isn't the proper temper-
ature you'll get variation in thickness.
Thickness of this layer in galvanized steel determines how long
it last when exposed to the elements. This isn't a good compo-
sition for coinage in any case because coins are exposed to much
harsher conditions and the edges aren't protected.
<< <i>
<< <i>By my rough calculations, the weight of the zinc plating on a '43 cent is about .056 grams. The total weight of the steel cent is 2.7 grams so the plating is about 2% of the total weight.
Hope that helps Toad1000 - and BTW - welcome to the boards! >>
Wait a minute. Zinc and copper are almost identical weight, and everyone seems to think the zinc coating on 1943 pennies is so thin as to be non-existant. So if the current copper coated cents are only 0.8% of the total composition - then how did you come up with 2% for the zinc coated steel? Just wondering how you cam eto your numbers, I wouldn't have the first clue on how to calculate it myself. >>
I thought modern cents were 97.5% zinc and 2.5% copper. Where did you get your 99.2/0.8 numbers?
<< <i>
<< <i>
<< <i>By my rough calculations, the weight of the zinc plating on a '43 cent is about .056 grams. The total weight of the steel cent is 2.7 grams so the plating is about 2% of the total weight.
Hope that helps Toad1000 - and BTW - welcome to the boards! >>
Wait a minute. Zinc and copper are almost identical weight, and everyone seems to think the zinc coating on 1943 pennies is so thin as to be non-existant. So if the current copper coated cents are only 0.8% of the total composition - then how did you come up with 2% for the zinc coated steel? Just wondering how you cam eto your numbers, I wouldn't have the first clue on how to calculate it myself. >>
I thought modern cents were 97.5% zinc and 2.5% copper. Where did you get your 99.2/0.8 numbers? >>
From the PCGS website, I think.
<< <i>
<< <i>
<< <i>
<< <i>By my rough calculations, the weight of the zinc plating on a '43 cent is about .056 grams. The total weight of the steel cent is 2.7 grams so the plating is about 2% of the total weight.
Hope that helps Toad1000 - and BTW - welcome to the boards! >>
Wait a minute. Zinc and copper are almost identical weight, and everyone seems to think the zinc coating on 1943 pennies is so thin as to be non-existant. So if the current copper coated cents are only 0.8% of the total composition - then how did you come up with 2% for the zinc coated steel? Just wondering how you cam eto your numbers, I wouldn't have the first clue on how to calculate it myself. >>
I thought modern cents were 97.5% zinc and 2.5% copper. Where did you get your 99.2/0.8 numbers? >>
From the PCGS website, I think. >>
Well, you are wrong. The current composition of the modern cent is 97.5 zinc, 2.5 copper. Maybe this changes your view on the 2% zinc coating approximation?
http://www.coinfacts.com/small_cents/lincoln_cents/memorial_cents/2000_cent.htm
So is it 0.8% mixed in with the zinc and then the copper plating brings it up to 2.5% total for the coin?
<< <i>Maybe I was misreading it. See link:
http://www.coinfacts.com/small_cents/lincoln_cents/memorial_cents/2000_cent.htm
So is it 0.8% mixed in with the zinc and then the copper plating brings it up to 2.5% total for the coin? >>
Yes, that would be correct. Therefore, 1.7% of the coin's total weight would be composed of the pure copper coating on the coin. Does that sound right to you?
<< <i>
<< <i>Maybe I was misreading it. See link:
http://www.coinfacts.com/small_cents/lincoln_cents/memorial_cents/2000_cent.htm
So is it 0.8% mixed in with the zinc and then the copper plating brings it up to 2.5% total for the coin? >>
Yes, that would be correct. Therefore, 1.7% of the coin's total weight would be composed of the pure copper coating on the coin. Does that sound right to you? >>
I don't know anymore. Not only am I an amateur, I'm a greenhorn amateur with water behind the ears.
So am I.
But this is one of, if not THE best places to learn about coins. You have come to the right place, welcome.
Repeating the above calculation with some rigor, I get .0514 grams for the zinc. I am still quite capable of making a mistake, though.
Now for some intersting oddities. According to the 1963 Mint Report and the 1950 Domestic Coinage booklet (price 15 cents then), the zinc coating was not to exceed .001 inch. Hence 4% total zinc would still be within specs.
Now the official weightS are fascinating. It was changed in mid-year.
By orders of the Secretary of the Treasury, December 23, 1942 and May 15 1943, the weight of the 1943 cent was 41.5 grains or 2.6892 grams and 42.5 grains or 2.754 grams. I presume the light weight coins came first but that is not crystal clear from the table. By the way, this is an average of 2.7216 grams. The Red Book states 2.70 grams. It looks like they averaged the numbers and then rounded it.
But in passing, I note they give the cent diameter as 19.05 mm. I used the 19 mm from the Red Book. Thus I have an error of (19.05/19) squared in my calculations. I need to increase my answers for the weights of zinc by 00.527% which is not much.
.
<< <i>I checked my 1976 Coin World Almanac for the 1943 cent specs. I was curious what weight they used. They gave the 42.5 grains number only. I find it interesting that there is no mention of the two weights used for the steel cent other than the mint reports.
But in passing, I note they give the cent diameter as 19.05 mm. I used the 19 mm from the Red Book. Thus I have an error of (19.05/19) squared in my calculations. I need to increase my answers for the weights of zinc by 00.527% which is not much.
. >>
The Redbook rounds a lot of specifications.
I worked on that specification chart for the Coin World Almanac, and we tried to be as accurate and official as possible. By law the diameter of the small cent was 3/4 of an inch. An inch is 25.4 mm.
25.4 times 0.75 = 19.05 mm.
As noted above, by observation the zinc plating on the 1943 cents is very, very thin and easily worn through. I have never seen a 1982-later zinc cent where the copper plating was worn through in normal circulation.
TD
Here is a thread that gets into the disposal of the 1943 cents which might of interest to you all. There is some contraversy involved there.
http://forums.collectors.com/messageview.cfm?catid=26&threadid=669373&STARTPAGE=2