Hi All,

I'm designing a part which requires fasteners, countersunk holes to be precise.

Say there are three parts which will fasten together. The one on the top is being modified and the bottom and middle part remaining the same. The bottom part has 4 M5 self-clinching nuts on the other end. The tolerances  are very tight to keep the holes on the top part to have them perfectly aligned. So do I go with stricter tolerances or can I create a M6 countersink hole for a M5 countersunk screw to increase the size of the holes a little bit? How loose would it be? Would it sit properly?

This is more of a real world physical sort of enquiry, I apologise in advance. I don't have any models to show.

Thanks,

Babar.