I recieved this Jefferson Nickel in the package from Lincolncent. It looks like the force to mint the nickel was not high enough to make a usable coin from it. The diameter is a bit smaller than that from a normal nickel but its is a little bit thicker than an ordinary nickel. All info about this is welcomed. Thanks
Think about what happens to a coin stuck inside a fin of a commercial clothes dryer. As the dryer drum turns to tumble the clothes the coin inside the fin is constantly bouncing around inside the fin. The edges of the coin continually strike the fins. Over time the metal along the edge moves inward, making the diameter of the coin smaller and the edges thicker. You can get a similar effect by "spooning" a coin.
I agree with "dryer coin". I have a nickel and a penny that look like laminate peel but they actually dryer coins.
Imagine someone pounding on the top of your head and the bottom of your feet for hours at a time. Eventually, you'd become shorter and thicker.