Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Steve" <alienrelics@y...> 
wrote:
> Oh, yeah, current USA "copper" pennies are copper plated zinc.

And lest anyone think they were pure copper before the 1982 change, 
ignoring the 1943 "wartime" steel cent, they were actually bronze
(95%copper, 5% tin and zinc) or brass (95% copper, 5% zinc)
depending on the time period - pure copper is much too soft to use 
for coins.

A.J.