A fellow engineer and I discoverd that a US penny is .75 in in dia and .060 thick. We measured other US coins and found that a penny is a usable gage- stack 16 high and you get a good approximation for an inch (close enough for govt work).
The other coins, nickels, dimes and quarters were odd diameters and thickness to be useful.
How’s them apples!
This is what happens when engineers remain unemployed for too long. Please, somebody give these guys a job, sweeping, painting, telemarketing; anything to occupy their hands and minds. 
djm
too soon…
they still have quarters
U. S. paper money is six inches long. Makes for a quick and easy measuring “stick.”
Ten penny nails.
If you find yourself stuck with only 5 pennies you could stack 4 and put the 5th on its edge on top to use as a 1" ga(u)ge. 
From Wiki:
As of May 26, 2007, the price of copper is $3.39 per pound and zinc is $1.67 per pound. At these prices, the pre-1982 copper cent contains 2.267 cents worth of copper, which makes them an attractive target for melting by people wanting to sell the metal at a profit.
Spray it viridian and you could have a green gage…
Do we need pennies? No. I’ve had the same two or three dozen of them in my car’s ashtray for 3.5 years. Time to stop minting the darn things.
But we do need dollar coins. And two dollar coins, too. And we need to just quit printing dollar bills when we start minting the coins, and tell the vending machine people to shut up, quit whining, suck it up and adapt their machines.
Or we could just start accepting Canadian loonies and toonies, which will be worth as much, if not more, than US dollars in, oh . . . about three weeks, at the present rate.
I would prefer that they just stop inflation and I could still buy a coke for 25 cents.
I’ll take four please.
LOL
Change in change is coming. It costs more than 1 cent to make a cent, and almost ten cents to make a U. S. nickel. So far the government has been eating the losses. However, if it continues, look for big changes in the change drawer.
The paper dollar would be long gone if it weren’t for certain powerful U. S. politicians that have printers or paper suppliers in their districts.
I seem to remember hearing or reading something about the US not owning the company that either prints or holds their money. Does anyone remember what the scoop is on that?
djm