@Xial Freedomheight is a humanist scale designed to represent the extreme highs and lows of a temperate european climate because Fahrenheit was a Eurocentric german.
Decimal inch is a useful bastard unit that applies metric principles to an archaic measurement system. But calling it a "Fifty Cal" is cooler than "Twelve point seven millimeter"
@Motodrachen
@Xial
Also measures are not cleanly convertible in whole measures at manufacturing tolerance sizes. And you can't use an M8 bolt in a 1/4-24 hole