A through-hole in a component that enables you to snugly pass a threaded screw/stud (or shank of) without interference or loose fit.
Use 7/64 as tap drill and 9/64 as clearance drill
If you want it to grip, drill a 9/64 hole. For a clearance hole, drill 7/32.
That size is 8-32. The drill bit for a clearance hole is 11/64, or a #17 drill bit.
For a clearance hole you need a 9/64 drill bit.
The parts of a twist drill include the shank, neck, flutes, land, body clearance, and cutting edge. The cutting edge is the point of the drill bit and does the actual cutting.
The clearance angle, also known as the relief angle, should not be changed while drill grinding. This angle is crucial for allowing the cutting edges to clear the workpiece effectively and prevent binding. Maintaining the correct clearance angle ensures efficient cutting and enhances the lifespan of the drill bit. Adjusting other angles, such as the point angle or lip angle, can be beneficial for specific applications, but the clearance angle must remain constant.
A 20mm or 13/16 drill bit will allow the bolt to fit through.
A 10 cm hole is almost 4 inches ! ! - IF you meant 10mm, then that's a little over 3/8 of an inch, or 13/32 for a clearance hole.
You sharpen the top, follow same clearance angle, you should not sharpen the face(flute) this can cause the od of the drill too shrink, drills are tapered in length and twist drills have a very small radial land unlike a reg drill. If you take a lot of stock off you will have to resplit the chisel point back to center. If you resplit, hold the drill at a 30deg angle so it cuts faster at center.
Most technicians have a steel ruler with metric on one edge and SAE on the other edge, so it's easy to calculate. Many technicians of all kinds also carry diaries or small log books with tables of this and much more technical information. One of the charts in my diary has drill sizes in decimal, SAE and metric, also tapping drill and clearance drill sizes for bolt and screw threads.
Not unless it was reasonably loose. Usually when faced with this, I drill into the bolt with a very hard drill bit a tiny bit thinner than the bolt - ie if it's a 3/8 bolt, I drill in first with a 1/8 drill to create a guide hole, then after with a 5/16 drill to cut right through, yet not harm the threads. You have to be very careful to stick to an exactly straight course. After the hole is cleared, I pull the threads left from the bolt out as far as I can, then use a 'clearance' tap of bolt size to re-tap the hole.
Valve clearance