Hello to all, this is my first post. :þ
You've to also forgive my crappy technical explanations if there'll be something I won't express properly, mainly because I've never learned these exact terms in my almost 8 years as a CNC lathe operator starting from scratch, and on top of it my past school background differs from my job, so what I've learned is grounded directly from the workshop.
We've recently changed two supervisors, and our working methods have changed for the better, providing us -finally!!- with appropriate tools. Some past techniques still remain though, like grinding drills by hand and/or using the grinding machine in a slightly different way. I've learned, for instance, to sharpen unevenly the cutting edges; the result is to have a bigger hole from a minimum of 0.05 [mm] up to 0.4 [mm]. It's good for deep drilling so the diametrical cutting edge of the drill bit doesn't friction during the path, wearing it and in the worst case destroying it.
Material 1.2311, drill Ø8 x 83 [mm], drilled automatically with the lathe (can't recall the feed nor the rpm, sorry); I've drilled 54 pieces without the need to sharpen more than once (before starting); the hole wasn't important so it could have been almost up to Ø9.
Sometimes if drills are too precise, well, they just don't fit for the job. Of course I'm not talking about those modern bits with inner refrigerant holes, eh?
Erm, didn't want to show-off nor be a smart-ass, just wanted to share a little info I THINK might be useful.