Some various types of shins (coins) from the Numenera RPG. They are quite thin(1mm), as I wanted to be able to print a large pile of them before my game that I was running 2 days after I modeled them, but you could easily scale them in the z-axis only to get shins that were roughly coin thickness (1.75-2mm would be about right).

A not on printing: Do not print with supports. I printed them with 100% infill (which doesn't really matter at this thickness) and I also printed with concentric fill for top and bottom layers. This gave the coins a nice circuit-board-ish look to them that I think will look nice with a dark wash of paint. Due to the overhangs and bridges, you will wind up with some odd bits that try to print in midair if you do this, and thus they will be a bit rough, but I think it just adds to the character of the coins and looks fine in the end.