Hi! I've had a friend who's found a piece off a heli possibly? any mechanics who could recognize this?

[emory3134]

[Nearly Retired]

It's not an aircraft part.  Aircraft use hardware with some sort of safety device: Safety wire, cotter pins, or threads with self-locking capability. Whatever that is, those nuts (not to be confused with Deez Nuts) have none of those things.  Ergo, not an aircraft part.