"tonyjeffs" wrote in message
...
I've just knackered a £12 sds drill bit after one session, cutting a
big hole in a wall for a wc waste,
Usually, I dip a bit in cold water occasionally in such circumstances,
but i got lazy and was impressed the way that SDS bits are slow to get
hot.

Anyway
Tips on sharpening drill bits generally? angle, ordinary hammer, SDS
Many of the sds bits have a sort of nipple on the end, almost a bell
or bobble hat shape - is that important ?
I generally try and sharpen things dangerously with an angle grinder -
a stone takes forever.
Can I maybe buy a bit sharpening machine?


Where do I find the FAQ - I ought to know the address by heart.
Thanks


Green Grit wheel or a diamond wheel made for the purpose.

http://tinyurl.com/5svmdo

Used on a proper bench grinder.
Gentle and slow sharpening with LOTS of dipping in water (Shock to carbide
will be insignificant) to prevent the braize from releasing the tips.
*Never* grind the sides of the carbide.
Follow the original shape if there's any left. If not then the front edge
grind back at the regular 59 deg angle from centreline (Much the same angle
as a normal drill) and just take off the front leading edge face by about 1
to 2mm to give the drill a negative approach. Take care to keep both lands
equal or it will lead off from centreline when in use

I used to "refurbish" SDS and other drills in the same way while in plant
hire and they worked fine.