How To: Sharpen twist drills

[Mike K]

Ah yes, the yellow coated Aldi drill sets sold in the round dispenser, good for about two minutes of use in mild steel Been there and I won't be buying them again.

A friend of mine has a Drill Doctor, not the 750 model but the smaller version that does up to 1/2" drills. We had a session playing with it. The Doctor is a somewhat fiddly and fussy instrument , it needs to be fine tuned for best results.

You can also buy centre drills. These are normally used on a lathe , the first step before using the normal twist drill when making a bore in a work piece . The centre drill makes a accurate dimple in the work piece for the normal twist drill to locate itself . Without the dimple, the twist drill will wander and walk over the work face.

There is a chap in the U.S, who has a career lecturing the engineering departments in universities on the science of sharpening twist drills !

https://www.youtube.com/watch?v=Ot8wPGQW3JI A good explanation of how centre drills work. Stefan is a typical German with his precision methods of machining .