as one on the recieving end of such things...I get to make it to the drawing... the tighter the tolerance (the more zeros you put in) the more expensive it becomes.
Many of my drawings are drawn using BS8888 (British Standard 8888) which superceeds BS308, which is in line with the ISO standard (world standard)
These standards cover much more than just the drawing layout and tolerances.
this subject could get awfully deep real quick if we're not carefull
Bye Bye now