Intentional Damage/mutilation. Shot with a square bullet. Filed down to dime size to fool old soda vending machine. Flattened with a press or roller type press.
1st "mutalated" coin I came across scrolling threw my pics... but considering it's age not sure if that counts as mutalated or is just "honest wear" at this point (1597 Fr Douzane Clementis VIII the coffee pope )
Looks more like nailed with a square nail. Some people used to do that for luck. Here's mine that's shot, probably a 22, probably by my wife's aunt or uncle while target shooting back when the coin was nearly new. Would this be "AU details"?
I have not seen a coin much more intentionally mutilated than this one. I received it in a large lot of foreign coins that somebody gave me years ago and have only hung on to it because it's silver.
There is a tool made for cutting sheet metal that could do that to a silver coin. They are made as a hand tool, power tool or air tool.
Looks like it was made into some sort of clip, like a paper clip. Odd that the top and bottom were squared off. There's a line scribed into it as a guide for how far to make the cuts. Clearly intentional for some purpose, but who knows what.
Personally I like square nail holes in coins. Trying to think if I have one that new or if every square nail hole that I have are either large cents and maybe a couple half cents?