Some cents weigh more than others?

Flash

I learned something new today while reading the lastest issue of Coin World. In one of the articles it was stated that cents made for the Mint and Proof sets contain two layers of Copper over the zinc, instead of the normal one layer that regular circulation strike cents have. I thought that was interesting and just wanted to share.

cladking

Thanks. It's news to me, and will take it under advisement.

richbeat

Thanks a lot for posting this. I didn't know that either.

FlyTooHigh

Even still the extra layers...the Mint continues to put coins going into mint sets into a barrel and rotate the hell out of them before they seal them in the cello!

Dog97

First I heard of it. I think the writer made a mistake.

MacCoin

thats right if the dog hasn't heard about it. it ain't true.

hookooekoo

Matt,

Your subject says "some cents weigh more than other" and made me think about the 1982 cents.

But your post talks about two layers of copper and doesn't say a thing about weither they weigh more (or was that the question).

In case the question wasn't asked, I will... Assuming the two layers of copper story is true, the question becomes, are Mint and Proof set cents heavier than business-strike cents. The copper is just electroplated on the coin. The extra weight of a 2nd layer of copper could be so insignificant that the total weight still falls within tollerances for business-strike coins. Even if the 2nd layer of copper did impact the weight, the mint could be making up for it by using less zinc in the base layer. Anyone got some concreate numbers on any of these figures?

hookooekoo

To somewhat answer my owe questions...

U.S. Mint web site says that a Cent weight is 2.500 g with 2.5% Cu Balnace Zn.

If they (1) used the same zinc base and (2) copper plate it twice with (3) the same amount of copper per layer as on business strikes, THEN a proof coin should weigh about 2.563 g.

Spooly

Thats right if the dog hasn't heard about it. it ain't true.

LOL!

Conder101

But the tolerance allowance for a post 82 cent is .1 grams (2.6 grams) so a proof or mint set planchet with two layers of copper is still comfortably within the mint tolerances for a business stike planchet and so not identifiable by weight.

cladking

Yes, but the average mint set coin would still be heavier than the average regular
issue, and some mint set coins would probably be outside the weight tolerance on
the high end.

Dog97

I would think that IF the Mint wanted more copper to prevent the zinc from showing thru from the increased pressures of a Proof strike they would simply have the planchet manufacturer apply a thicker layer of copper rather than running the planchets through the plating tank a second time. No facts, just speculation on my part.

lathmach

I'm with Dog on this. It doesn't make any sense to run the planchets thru a plating process twice.
Copper over copper is just thicker copper.
The planchets are barrel plated prior to minting.
I didn't read the article, but I will and try to understand what the writer was getting at. I think he may have been confused, too.

Ray

Flash

Here is a link to the Coin World article I was referring to. Article

A quote from the article:

Planchets for circulating cents receive a single copper plating, while those for Uncirculated Mint sets and Proof sets receive a double plating of copper.

Dog97

Back in the old days they used the same planchets only they were burnished then annealed differently than biz strikes. Maybe they meant a "double thickness" rather than a "double layer." Maybe this might be something new.