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Point angles are relative to heat coefficiants in production.
The broader point allows less heat over an effected area because there is lees area in contact.
A sharper point has longer cutting edges which means more area in contact.
Anything between 118*- and 135* is fine for general stuff.
I always grind a 135* angle for garage use. Because holding a hand-drill steady is impossible. The 135* angle could handle more abuse.
If you're drilling large holes with a pilot, buy a single flute chamferring tool. Drill your pilot and then chamfer the crap out the hole, atleast to hold captive the next size drill. If you pilot 1/4" and the next drill is 1/2" the big drill will chatter until it buries the tip, creating a triangular mouth.
Plus the chamferring tool is just good sense to have, nice clean holes, everybody wants them.
The broader point allows less heat over an effected area because there is lees area in contact.
A sharper point has longer cutting edges which means more area in contact.
Anything between 118*- and 135* is fine for general stuff.
I always grind a 135* angle for garage use. Because holding a hand-drill steady is impossible. The 135* angle could handle more abuse.
If you're drilling large holes with a pilot, buy a single flute chamferring tool. Drill your pilot and then chamfer the crap out the hole, atleast to hold captive the next size drill. If you pilot 1/4" and the next drill is 1/2" the big drill will chatter until it buries the tip, creating a triangular mouth.
Plus the chamferring tool is just good sense to have, nice clean holes, everybody wants them.
