I never had issues with cm/mm honestly. And half a milimeter is always a precision hard to reach with home hand tools, so the need to have 0.33 milimeters on a

I never had issues with cm/mm honestly. And half a milimeter is always a precision hard to reach with home hand tools, so the need to have 0.33 milimeters on a ruler is not there. Tools that reach that precision are in micrometers.