This is my first time seeing a call out like this. What is the benefit of dimensioning this way?
I feel like it would be more beneficial for tolerance stack to increase the perpendicularity to .002 - .010, remove bonus tolerance, and decrease the width allowance.
Unit is inch
The call out is for the width of the part, not a hole
Traditionally, a designer will split tolerance between size and form. Often the parts do not meet the stated tolerances of one or the other but they still assembly and function as intended. So the designer will change size or form tolerances while still retaining the 'virtual condition' of the part. What zero tolerance at MMC does is say I don't care that much about size or form just so the part mates to the next assembly.
Traditionally, a designer will split tolerance between size and form. Often the parts do not meet the stated tolerances of one or the other but they still assembly and function as intended. So the designer will change size or form tolerances while still retaining the 'virtual condition' of the part. What zero tolerance at MMC does is say I don't care that much about size or form just so the part mates to the next assembly.
One other nice thing is that if you make a hard gage for hole locations is that the pins in the gage will do double duty to verify both location and GO size
