depending on the year of the penny, it could be an impromptu Miner ID tag. Similar to a soldiers dog tag, the number would be the miner's ID number in case an accident occurred and if a body was recovered the penny would help identify him. OR it could be an equipment number to a piece of machinery with the penny being used as a key fob. However.... the lack of a hole for a key ring or lanyard to go through kinda eliminates these two theories. Interesting penny!

The penny is from 1993 I cleaned it some

Well, that shoots down my theories lol.

It's from 1993 but I like your theory!

I don't think it's engraved, I think that was stamped into it with a hammer blow, dented into it, not scratched out of it. I wonder why, I have never seen anything like that. I once drew cat ears and whiskers on George Washington on a 1 dollar bill, and I could understand melting it down for the metal, but stamping 984 in a coin is a mysterious action.

I know its totally bizarre

It is definitely a stamp job. I have the dies that one would use to make those numbers. The coin is slightly buckled, and the numbers are not in line, so this was probably stamped by hand one number at a time. Pennies are usually a soft metal, originally copper, but later plated aluminum. So they are easy to stamp. The first poster has the best theorey here so far...

Hard to make out the date on the penny, 19x7 depending on how I stare at it x=9, 4, or 1. What does the obverse of the coin look like? (That would eliminate two of those possibilities. 1997 would have the Lincoln memorial. 1947, or 1917 would have the wheat laurels on the back.

It has the memorial on the back.

The penny is from 1993 I cleaned it some its shiny lol

Well, that clears up the time frame, just the question why, then. Could have even been a rather bored soul playing with metal stamps! =^^=

I know I was hoping at least the 80's but I was disappointed really.and probably so but its still interesting