On Nov 1, 9:20 pm, "Will" westes-...@noemail.


And I would suggest that you use split point high cobalt steel
bits for the task, instead of the more common HSS bits.

What advantages do those have?

Much info is already here on this subject, but as a piece of practical
information: The most common configuration of cobalt HSS drill bit
seems to be the 135-degree split point, which is what you should
look for. The split point is indeed best for the application, and has
tha added benefit of being able to self-center more accurately. These
bits are available as well in screw machine length (shorter than
jobber
length), which makes them more rigid and less apt to wander.