I have substituted these NAS1801 hex cross head machine screws to replace the NAS623 pan cross head that I have used in the past given that all thread is OK and the screw is subject to frequent removal. Given the hex head of the NAS1801, I can use a socket to remove and tighten up the screw whereas with the pan head, one must use a Phillips screwdriver regardless. Tightening and loosening using the hex head means the cross recess remains intact and hence available for initial placement and final removal. Also given that the screw is all thread, then length is not as critical as with the long shank short thread length NAS623 machine screws.

My favorite screws because of the nutdriver or socket positive grip for tightening and loosening but can use a Phillips too. Strong too at 150,000 psi. Great screw.