Quote Originally Posted by hemmjo View Post
Let us not forget about the gradian, also known as the gon. 1/400 of a turn, 9/10 of a degree, or pi/200.
Fortunately, it never became part of SI though. I've never seen it used here in the USA.

Worse are the machinists who term a thousandth of an inch a "mil".

One has to be careful with "mil" since it's one of the common terms for milliradians. an SI unit...

https://en.wikipedia.org/wiki/Milliradian

Also the artillery setters use it as an angular measure. However, to maintain the spirit of inferial confusion, they've "rounded" the 6283... milliradians in a circle to 6400. I suppose the (admittedly slight) error so induced is compensated with more explosive shells.