I must confess that my skills at sharpening drill bits is totally unacceptable, worse and awful. That said I’ve tried some widely recommended sharpening methods, I even purchased one of those electric sharpening machines and I’m still extremely unhappy with the results. As many of know there are varios drill bit angles and these fancy tools seem only fitted to sharpen one angle, which everyone they designed into the grinder wheels. According to the attached drill bit chart there are about 4 or 5 angles for different types of materials. Got it! I have two questions: what machine can use to get all of those angles? What’s the best drill bit angle to drill these vintage vehicles steel parts?
The material you're drilling will usually be the determining factor of the angle the bit is sharpened. For regular non-hardened "mild steel" material that most of a stovebolt vehicle is made of, the usual 118 degree sharpening angle works well. Softer material such as aluminum or brass can tolerate a more pointy angle, while hard metals such as tool steel or drill rod need a flatter grind and a slower feed, plus some cutting oil or other lubricant. Here's an inexpensive set of sharpening guides that can be used with a regular bench grinder:
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
When sharpening drill bits, it's very important to get the drill point in the center of the bit. If not, you will be drilling the holes oversize. Probably not important for most circumstances, but very important when drilling a hole to be tapped.
John
~ J Lucas 2006 GMC Envoy 4.2 I6 2023 Ram 2500/Cumins 6.7 I6 2010 Jeep Grand Cherokee (Wife’s) 2002 Silverado 2500 Gas 6.0 1941 Chevy 1/2-Ton 1942 Chevy 1.5-Ton SWB In the Gallery My Flicker Photos!
Did anyone else learn drill bit sharpening in high school shop class? I feel lucky to have. I’m not great at it , but using a drill gauge for both the tip angle and the chisel edge angle, I can get a pretty good job. But usually it’s just a quick by eye dressing on the grinder!
~Charley 1954 Chevy 3100 with 235 “Bud” Follow along in the DITY 1963 Chevy half ton stepside short box 230 1954 GMC 3 ton 302 And several more Chevy camper and work trucks 1979 1987 1996
Another factor to consider is the "relief angle"- - - -the taper of the bit helix behind the cutting edge. If the bit isn't tapered back a little from the sharp cut edge, the bit will "skate" and overheat instead of cutting smoothly. Too radical of a relief, and the strength of the cut edge is compromised. That's a skill that just about has to be developed with lots of practice- - - -I don't know of any guide fixture that can do it consistently. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I use a Craftsman p/n 96677 attachment for the bench grinder, I was a kid when dad bought it and I kept all of the tools he had. It does a great job on bits and adjustable to any angle.
1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy
