Copper or Bronze?

[wdrob]

How can you tell the difference in a penny. If it is copper or bronze? Is bronze magnetic?

[BillJones]

Bronze is not magnetic. The best way tell is to look it up in book for the coin, medal or token. The tiny amount tin that is added to the mix makes bronze less reactive and more duriable while in circulation. The difference color is minimal when new and red; impossible to spot when it tones to brown.

[wdrob]

Copper is not magnetic either is it?

[bsshog40]

Copper is not magnetic either is it?

No

[wdrob]

I think I am figuring out what I have here. It seems to be a mixture of Bronze and another, the small date seems to be Zinc Coated. So I think I have a 1982 LG Date Bronze based upon the die marks as compared to the other pictures. It is in the best shape and all are red.... Actually just like they came from the mint.

 

I think the 1982 Small Date is Zinc Coated. Once again based on pictures and the porous nature of the surface and a couple of raised surface spots in the coating that looks like someone painted a fence..

 

The other 82 Large Date seems to be copper since it has a couple of those dark spots that develops on copper. Nothing here worth much that is for sure.

[AuMorgan82110-migration]

Large cents were copper up to the flying eagle when they change to a copper/nickel alloy. Indian head small cents were copper/nickel until 1864 when it changed to bronze. Its funny that reading the Red Book they mention that the lincoln wheat reverse composition is bronze, but when they call out the memorial reverse they call it a copper alloy. Both are the same materials and ratios. In 1982 when they switch to the zinc core the ratio changed drastically, and I wouldn't even call it an alloy. Weight (4.67 for the copper/nickel, 3.11 grams for bronze/copper alloy, 2.5 grams for copper coated zinc) is the best way to tell. Another way I have found to tell the difference between the alloy and the clad is if you drop them on edge on a hard surface, like a countertop, the alloy ones will have a ring when they bounce, and the clad ones will have a bit of a clunk. I would go with the weight if you are doing anything other than putting them in an album where you can't see the edges.

[wdrob]

I didn't think about weighing them. Thanks. I will do that now.

 

 

****Edit: Yep that confirmed it. That 1982 Small Date is Zinc and the rest, including of-course the 1909 VDB, all came out to 3.1... Thanks!

 

 

 

[BillJones]

I didn't think about weighing them. Thanks. I will do that now.

 

Weighing the item will help you determine if the piece is copper plated zinc, but it won't help you if you looking to see if an item is copper or bronze.

[johnny9434]

Copper is not magnetic either is it?

nope not in the least bit

[RWB]

In 1941 most of the tin was removed from the US cent. This left it 95% copper and 4+ % zinc (this is really "brass").. That composition was officially maintained into 1947 and the amount of tin only gradually increased to about 1% later. In practical use, all the mints did was add enough tin to keep the coin within legal specifications. (See: “United States Pattern and Experimental Pieces of WW-II” for a lot more info.)

[jayman1970]

If you are referring to 1982 cents, they are either .950 copper and .050 zinc or 99.2% zinc and .08% copper with a plating of pure copper, no bronze!

[BillJones]

Tin is a rarer metal than some people think. It probably goes back to the cliché "tin cans" which implies something that is common and cheap. Tin is not that common which probably explains why the government substituted zinc for it in the cents after WW-2.

 

 

[wdrob]

If you are referring to 1982 cents, they are either .950 copper and .050 zinc or 99.2% zinc and .08% copper with a plating of pure copper, no bronze!

 

Then you definitely need to let NGC know this information.

 

 

 

They seem to be under the impression that they made pennies in 1982 out of bronze.

 

 

[mumu]

I collect a darkside series that has an issue in Krause listed as having been struck in both copper and bronze with different figures for each. No idea how to tell which is which. I suspect Krause is wrong though.

[Conder101]

They stopped making cents out of Bronze in 1963. That was when they took the last of the tin out of the alloy. From 1963 to 1981 all of the cents were made of brass, and so were some of the 1982's. The only bronze cents since then have been the Mint set and proof set 2009 cents. NGC is wrong when they call those 1982 cents bronze.

[wdrob]

 

 

 

Well you better let PCGS know also:

 

 

They all got it wrong.

[newprepper]

They also graded all my MS70 lincolns wrong