I have Nema 24 steppers (24HS34-3504D). They call for M4.5 socket head screws which are difficult to find. I tried an M5 and it is really snug. any suggestion for a screw size, metric, fractional, or numbered?
A #8 screw will be a little undersized (4.06mm) but it's probably as close as you're going to get and should work fine. If you're wanting to go bigger you can always drill out the holes in the stepper.