The diameter of the shaft d1 at the counterface should be machined to the tolerances provided in the table for metric shafts and in the table for inch-size shafts.
Out-of-roundness must be less than 0,005 mm (0.0002 in.) at a maximum of 2 lobes or less than 0,0025 mm (0.0001 in.) at a maximum of 7 lobes.
If components with an interference fit will pass over the counterface during installation, the shaft diameter should be reduced by 0,2 mm (0.008 in.). The seal that was originally chosen can still be used without adversely affecting seal performance.