Hex wrench size chart

[mklotz]

This chart may be of some help as additionally to the SAE sizes it lists fractional as well as metric but not the set screws

Socket Head Cap Screw Size Chart

For the fractional SHCS, I simply remember the rule(s)...

If less than 1/2 subtract 1/16 from the screw size to find wrench size
else
If less than 1 subtract 1/8 from the screw size to find wrench size

I've never seen a 1" SHCS much less anything larger but there are similar consistencies as one goes up into those Brobdingnagian sizes.