A lot of that depends, get you a mil spec bolt or nut, the tolerance is +\- .0002. Standard SAE is .002 +\-. At least for what we can procure for our contract project
Plus a lot of that also comes to dealing with quality of sockets as well. No BS, snap on, McCorrmick, Cromwell, even Mac, all not only fit tighter but some, like Snap On, have a dedicate Mil Spec tolerance for the tighter tolerance. We run into this every month at work with procurement