Coin Is Blank On One Side - Please Help Identify It

@superban, first welcome to CCF. Second, it is a whole lot easier to answer those questions if you could please post pics of both sides of your coin. Here is a link to the tutorial if you are having difficulty:

https://www.coincommunity.com/forum...g-images.asp

Thank you. Please see the pictures I uploaded to my post.

The coin weighs 11 grams and is 2.7 cm in diameter.

Why would someone grind off one side of a coin? Is that common practice?

People ground one side off two coins then glued the two halves together to make a double headed / tails coin.
Sometimes they were done by taking the edge off one and insering in another as an excersise from somebody probably bored.
In answer to your question as to why it was done.

@superban, it appears that the original coin was a British florin (2 shillings). I cannot tell if it is the copper-nickel or the 50% silver variety. If copper nickel it only has curiosity value, if silver it has that and the silver value.

As to your question "why", it is important to realize that ANYTHING imaginable that can be done to a coin, with a hammer, saw, drill, lathe, etc. can and has been done to it.

Coins have been used as raw material for jewelry, etc. for a long time, because they are handy, and years ago an easy way to get a bit of silver to work with.

Previous threads have suggested that young boys are more prone to destructive alteration of coins, but this looks like carefully planned work.