Odd Weight for a 1982 penny

By the way.. Did you like the examples I showed you from my collection?

 

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I do appreciate that you went the extra mile. My collection is more sentimental. Thin errors aren't too exciting for me. I'm sure your collection is crazy elaborate. I mostly roll my pennies.

 

I understand. And I hope I can address you better next time.

Welcome to CoinTalk!

 

Is there any amount of value with a slightly thin penny like what I have?
Should I treat this penny special?

 

yes

 

If I was looking for another as a collector. I would be interested in it. It's not a major error but a nice one.

 

It's true that a 1981 Canadian penny is bronze and weighs 2.8 grams.
However, they have their own mint the US doesn't have Canadian planchets in 1981 to mint a 1982 cent on. Even if, a mint worker accidentally dropped a Canadian copper cent that weighs 2.8 grams into a bin of 1982 US copper cent planchets, you would be able to see both designs on the coin.
You might have a slightly thinner rolled planchet as discussed.

 

Alright. I know you guys all think I'm the new crazy guy. But I've done some more work. I am able to pretty accurately measure the density of the penny without destroying it. The density (taking all the materials into account) link up pretty will with a 1981 Canadian planchet. It doesn't link up with any 1982 american penny. Even if the planchet was on the thin side, it would have the same composition. Or do thin planchets, just not have any zinc? I know the Royal Canadian Mint provides planchets to many countries. Could it be that leftover 1981 Canadian stock was shipped to america to mint. Since they seem the same, something like that may never be noticed. Do any of you know a way to figure out if tin is in a penny without destroying it?

 

Alright. I know you guys all think I'm the new crazy guy. But I've done some more work. I am able to pretty accurately measure the density of the penny without destroying it. The density (taking all the materials into account) link up pretty will with a 1981 Canadian planchet. It doesn't link up with any 1982 american penny. Even if the planchet was on the thin side, it would have the same composition. Or do thin planchets, just not have any zinc? I know the Royal Canadian Mint provides planchets to many countries. Could it be that leftover 1981 Canadian stock was shipped to america to mint. Since they seem the same, something like that may never be noticed. Do any of you know a way to figure out if tin is in a penny without destroying it?

 

Not a Canadian planchet.
They made 17+ billion cents in 1982.
But you have the 1 coin minted on a Canadian planchet,
without any way of it being in the US mint.

 

But how do you know there is "no way" there are lots of examples of coins being minted on the wrong planchet. Even crossing countries... There could be hundreds that have gone undetected. Nothing really stands out about the coin. I guess I'm looking for people that know how to eliminate possibilities scientifically or historically. Sarcasm doesn't really help me. If someone knowledgeable says, "when it comes to thin planchet the composition tends to be different and it could just be missing the zinc" That would be knowledgeable and helpful. That would explain the denser penny compared to an American penny.

 

@James Miller Can you explain how you did your density calculations?

 

To find the actual density of the penny, I measure it with a calibrated scale. Then we have this fixture that allows you to suspend the coin in liquid, but still weigh it. There will be a difference in weight. If you think about picking up a 10 pound rock. Then go into a lake and pick up a 10 pound rock. It's easier... So basically you first finding the specific gravity as it relates to the liquid. From there it's math to get to the actual density of the penny. I found it to be between 8.91g/ml and 9.02g/ml
To find the theoretical density of a coin, I just use the known composition percentages and known densities of materials used. So the theoretical density of the 1981 Canadian coin is 8.93g/ml while the American copper 1982 coin is 8.87g/ml
No matter what, my penny has more copper content percentage then it should for an American penny. That's the only way the numbers work.
I wasn't sure if you wanted me to be more in depth with my calcs... I'm an engineer and have access to lots of test equipment.

 

I never said there weren't coins on foreign planchets.
What I said was yours isn't one.

I suggest sending your coin in to a grading service and
have it attributed as being on a Canadian planchet.

 

Wouldn't you feel more comfortable measuring a few copper cents instead of relying on a theoretical calculation?

Would you feel comfortable presenting that data as the basis for your conclusion to a group of engineers at your workplace?

The U.S. and Canadian mints did not do business at that time, so how could a stray Canadian planchet make it into Philadelphia? That would be the equivalent of finding a Can of Budweiser in your case of Coors.

As an engineer, you should know that extraordinary claims require extraordinary proof. I'm not saying what you did was wrong, it's just that it isn't enough. If you have a black belt quality engineer in your group, ask them on how to do your test so the data is credible.

 

I’m not ready to present my findings. I’m still trying to gather info. Unfortunately many people on this forum are quick to just give crap instead of giving real info. Yes, next week I’ll probably do more testing.
Like what years did America get planchets from other countries? I get it. American penny on Canadian planchet is impossible. I’m trying to figure out why it is the way it is. I’m looking for the logical, most likely thing. Instead I hear “it’s not that. It’s not that”
And I don’t know how “extraordinary” some things are vs other things. A thin planchet sounds just as likely as a Canadian planchet.

 

Be sure to measure on a scale that can show 2 0r more numbers past the decimal as many lower priced scales are only 1 number past and not accurate enough for what you want.

If you are that sure there is an alternate reason that would cause such and our answers do not satisfy you, then save your time and send it to a low price grading company as the similarity of copper and zinc can not be non-destructively verified by most of the metal testers at coin or bullion shops. If a bullion shop has a XFR gun, they can give you an answer usually for $50-100, or if you are really sure, PCGS can verify and slab for more. Argumentation doesn't help as you have the coin in hand and we just have what you present. Jim

 

The reason why you're hearing it's not possible is that the U.S. Mint DID NOT make any coins for Canada during the 70s and 80s. That is the logical explanation you said you were looking for. You also said you wanted to "find out when America got planchets from other countries". Answer = THEY DIDN'T (at least not since the early 1800s). At various times the mint made coins for foreign countries. These are well documented if you want to do the resesrch, and as I recall none were on cent sized 98% copper planchets.

However, there are error coins known on both thin and thick planchets (members even posted pics of these). If you research the coin making process, you'll learn that metal ingots are rolled into long strips of the specified thicknesses. And with any high speed manufacturing process, mistakes can occur. Your coin only weighs slightly less than the min tolerance, which means the strip was just a little thinner than spec.

So which scenario makes the most sense? That it was struck on a planchet that has no realistic way to be in the mint, or it was struck on a thin planchet, which can occur in the manufActuring process and examples are known to exist?

That's the problem, your making conclusions without understanding the minting process or history. The people that you say are quick to give you crap instead of real information, are giving you real info.

 

I guess I’m confused about this forum. I thought I might get some info. I’m not trying to convince anyone of anything. I’m not here for that. I’m looking for info. I’m trying to solve my little mystery. I’ve been on coin talk for a day and it seems like this is just a place to go to be talked down to.

 

You are assuming in comparing the Canadian and the American coin, that the mint was always accurate , but the metal is mixed in large quantities before rolling and punching out the planchets, which if they aren't clipped , should be the same diameter...but the mint allows a +/- variation of 0.13 grams for a variation range of .26g range total for the planchet.

This variation is usually not due to the diameter unless the collar is defective, but thickness or composition. Variation in thickness can be measured externally, but determination of composition content % usually necessitates a spectroscopic determination. Such cents can be dissolved in acid and then ratio determined by titration with standardized reactants, but the damage would be total. The XRF devices are more accurate when calibrated and non destructive, but they are more expensive than normal lab equipment and less available.

What I am trying to point out, is that I do not think the difference in density you have out would be convincing to any certification of the coin due to tolerances, but you should contact them if you go that route. Good luck, Jim