Thread: Drill bits for knife making

Good evening,
just a question to all the knife makers here..
What kind of brand / maker drill bits are you using for cutting/ drilling through old saw blades? unknown origin and steel composition.
I tried several bits,- Bosch, HSS, and Carbon bits bought from Mitre10 on the drill press using cutting fluid.
The bits where in size from 4mm-6mm.
Most bits cut alright two or three holes, one burned up, probably the speed was too high? the other ones just stopped cutting.
Neighbor gave me a masonry drill of all things and that one cut a couple of holes through the steel the other ones didn't even put a scratch on the surface..
Any advise would be much appreciated