Composition of the old small cents

[jlueke]

I noticed on Erich's 2009 proof cent the cents list a composition of 95% copper, 3% tin, and 2% zinc honoring the metal content of the original Lincoln cents. My references for the previous alloy always state 95% copper and 5% tin and zinc and I assume this is how it was listed in some mint reports. Was that 5% more precise in the old days or did the mint just want to be more accurate in 2009?

[Art1.2]

I noticed on Erich's 2009 proof cent the cents list a composition of 95% copper, 3% tin, and 2% zinc honoring the metal content of the original Lincoln cents. My references for the previous alloy always state 95% copper and 5% tin and zinc and I assume this is how it was listed in some mint reports. Was that 5% more precise in the old days or did the mint just want to be more accurate in 2009?

 

I have no evidence for my opinion on this, just observations and things I've read.

 

Supposedly the mix of tin/zinc was set by standards but not adhered to 100%. The color variations on cents of the early 20th century could indicated that slight differences in the mix were present. Of course after WWII when recycled brass from shell casings was used the composition was significantly off.

[jlueke]

I have no evidence for my opinion on this, just observations and things I've read.

 

Supposedly the mix of tin/zinc was set by standards but not adhered to 100%. The color variations on cents of the early 20th century could indicated that slight differences in the mix were present. Of course after WWII when recycled brass from shell casings was used the composition was significantly off.

 

The shell case (bronze minus tin) is listed for 1944-45 and there's obviously the steelies. But my Breen calls the rest from 1864-1942 and 1946-1982 "French Bronze" with the 5% tin and zinc.