Trailer ball mount upgrade

[Frank S]

I tend to be the same way about plasma or oxy fuel cut holes. When I tell a burner I want the holes burned 1/8" smaller in diameter than the finished hole needs to be. Their first response is but we can burn to within a few thousands in that thickness.
Cylindrical or conical I ask, and usually get the blank stare as if they have no idea what I'm talking about.