Re: [CAD_CAM_EDM_DRO] Flat Holes

> Is there a special type of drill bit to make holes with perfectly
> flat bottoms? All the drill bits I see are somewhat tipped. I want to
> make flat-bottomed holes so I can recess socket head cap screws.

What you want is a device called a counterbore. It is designed
specifically for what you want to do.

End mills also work, provided that they are centercutting or that the
pilot hole (clearence hold for the screw body) is wider than the
non-cutting area in center between the flutes. Also being hardened
shank drill chucks won't grip them well - they are better held in
collets (MUST be held in collets for anything involving side cutting
forces)

In a pinch one might be able to do evil things to a drill bit with a
grinder. Boring bar in an offset boring head, or clevely ground tool
bit in a fly cutter also also within the realm of possibility.

Chris