Originally Posted by
motorapido
I hadn't even considered the chamfer on the stud. I think this is a risky setup. Note: nylock insert is at the top/exit of the nut, not the entry, luckily.
Is there a place to find a millimeter or two, ie. remove a washer someplace? If not, and if this is on the front, you can drill the back of the fork to 8mm (5/16") and use a recessed nut. No need to counterbore, the flange of the nut can sit outside the fork. If you go this route, you'll need to shorten the bolt about 4-5mm or so.
If this is a rear brake, odds favor you if you go ahead. The brake won't tear loose in use since it's pushing not pulling on the bolt.