N. Thornton wrote:

My point is that these reground bits are much better suited to
woodwork than the gen purp bits most of us crawl along with.


I took it as obvious that the whole engineering world had a lot more
experience. That does not however mean that one can not up one's work
rate by using sharper angled drills than the usual twist bits. These
bits are performing much better, as long as you accept the limitation
that they are for wood and not to be used in concrete etc.

Hollow grinding and "spear-point" grinding are used where the material
being drilled requires, brass requires a very shallow grind (the exact
opposite). I've hand sharpened upto 2 inch twist drills, and hollow
grinding to reduce the web on larger drills is quite the norm, in
smaller sizes less so, either way grind them to suit the job, not to
some idealised average and you'll always get a better result.
Some rolled twist drills with slow twist will never drill true and round
even if/when they are straight, but then they are for fast production
use to do a job and get binned when they blunt, higher quality drills
are worth re-grinding, the average monkey cannot re-grind a drill these
days, so often all you find is cheap, crap, drill bits upto 13mm, if you
find good ones I'd get several sets and keep one for steel, and another
for wood, ground to your own spec. I still use a slip stone to fine tune
drills and other tools, but then I'm rather old school and passe these days!

Niel.