Presidental Dollars

88.5% copper, 6% zinc, 3.5% manganese, 2% nickel

The gold plated ones have such a thin layer of gold that it doesn't increase the value at all. Numismatically speaking...it hurts the value since the coin is now considered "altered"

And all 3 (or 2) have the same electrical signature as the SBA.

Well, electrical signature means that if you put it in the vending machine, there's usually a wire that passes a current through the coin and another on the other side to see how much energy has passed through. Each coin has its own signature.

For example if 1 Joule is passed through an SBA, it should have .5 coming out. So, a machine expects that amount. If it's anything higher or lower, the machine will reject it. It's kinda like magnet test against Canadian coins being used in the US except more technological.

So yes, even though they're composed of different metals, the mint made sure it had the same electrical signatures so vending machine owners won't form an angry mob protesting having to recalibrate their machines for a new coin.




And that's why the new composition is so odd. 3.5% manganese? Who uses manganese for a coin, seriously?

Also to take a blast to the past, it was the same reasoning for the silver War nickles. It had manganese to make the silver and copper alloy the same signature as the old 75/25 nickles.

The principle of electrical signature is also why Coin Stars will reject silver coins in addition to foreign coins and slugs.