Sharpen Your Drill Bits

Step 15 The finished bit

This is how your bit should appear. Notice there are no longer any worn, rounded cutting edges casting glints of light. Everything is sharp and crisp. The length and angle of the cutting edge at the tip of the drill bit are good, too.

Comments

[GadgetBuilder1]

Drills with grind lines parallel to the lip tend to fail prematurely due to flex at one of these grind lines. See the picture here for an example of this failure:
http://www.gadgetbuilder.com/DrillSharp.html#Inexpensive

Raising the contact point well above the grinder shaft avoids this problem.

[HarryMann]

Yes, that edge is commonly called the chisel edge of a drill. It is indeed a good guide as to whether the sharpening has been succesful. The cutting edge ideally wants to be straight rather than curved, though its often hard to determine why it won't come right with some drills...