1985 Dime Error

Are you sure it is post mint? The front of the coin is almost dished and if you look at the "dot" there are lines that look like the lines on the torch. I could be wrong it just caught my eye so I was seeing what exactly it was.

It is post mint. This alteration was done to create a cuff link, a button or some other form of novelty piece.

It could even be a more modern version of a "spinner". Coins or medal like objects were made that had a small raised dot on one side. You could lay the coin on a bar or table surface and spin it.

Spinners traditionally were used to pick a person to pay the tab after a round of drinks.

With this dime, perhaps, it was made into a spinner. Whoever Roosevelt was looking at after the thing stopped spinning was stuck wit the bill.

Have Fun,
Bill

Something to think of as well - your comparison to the other dime is not a fair comparison because they are from different years. The design was re-engraved a few times in that period. which is why the older one has very little hair detail and the newer one has more hair detail. They are essentially completely different - yet similar - designs.