by using a drill
The recommended drill bit size for a 15/64 inch hole is a 15/64 inch drill bit.
The recommended size of the drill bit for a 7/16 inch hole is a 7/16 inch drill bit.
For coarse threads (13 threads per inch) use a 27/64 drill
A 3/16 inch pilot hole drill bit should be used for installing a 1/4 inch screw into hardwood.
For a clearance hole you need a 9/64 drill bit.
7/8 diameter drill or .875
It depends on the material you are fitting it into. In most wood I pre-drill a 1/4 hole for this. In softer woods i would drill a smaller hole .
5/16 hole X 4 inch on a flat bottom hole: This will depend on the material, and tools available. Use a 1/8 bit, then 5/16. If you are not sure how deep the drill bit is in the hole, paint white out on the bit as your 4 inch mark so you can see it while the drill is spinning. If the material is metal, you will need coolant. To get the flat bottom: it wood, put a flat ended bolt into the hole and hammer, it will flatten the hole, it metal, forget about it, the hole is quite flat, and a pain in the butt to change. :-)
i would use a long shafted hole saw
One that's too big for you to hold.
.50 drill bit = 8mm rubber grommet
use a half inch drill