Search:

Hey, in mm the number is much bigger :roflmao

No, actually even if you visit Aust, Revisor, Wacker, TI websites in their native German/French, you'd still find the width in fractional inches. The length when mentioned (rarely) would be metric....

This alone doesn't explain it: you guys are the only ones still using it, and why would it make a German manufacturer selling in Europe use fractional inches?
I think traditionalism and conservatism...