In an interchangeable assembly, shafts of size $${25.000^{\matrix{ { + 0.040} \cr { - 0.010} \cr } }}\,\,mm$$ mate with holes of size $${25.000^{\matrix{ { + 0.030} \cr { + 0.020} \cr } }}\,\,mm.$$

The maximum interference (in microns) in the assembly is

A hole is dimension $$\phi {9^{\matrix{ { + 0.015} \cr { + 0\,\,\,\,\,\,\,\,\,\,} \cr } }}\,mm.$$ The corresponding shaft is of dimension $$\phi {9^{\matrix{ { + 0.010} \cr { + 0.001} \cr } }}\,mm.$$ The resulting assembly has

Ring gage is used to measure

In order to have interference fit, it is essential that the lower limit of the shaft should be