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Are there better drill bits than cobalt?
Posted: Wed Sep 01, 2010 7:15 pm
by Zombie Master
I've tried those titanium bits, and the ones I've tried sucked. So far Cobalt seems to be the best.
I'm all about drillin'. How about you?
Re: Are there better drill bits than cobalt?
Posted: Wed Sep 01, 2010 8:21 pm
by Major Softie
Yes, there are better bits than cobalt: cobalt. Cobalt is not all the same anymore than steel is all the same. I know M-35 and M-42 are two different cobalt drill bit grades, but there are probably more. Also, there are solid carbide bits, and they're even better.
Of course, "better" is another issue. In general, harder bits are more brittle, so the harder bit may not be as good for certain jobs.
Plus, there are different tip angles, with each better suited to certain work and certain materials, and different coatings, AND even different twist rates and split points and heavy-duty bits and die drill bits and straight flute and spotting drills and...
Plus, the best quality bits from the top companies really do work far better, even if they are from the same materials.
Take a look at the Enco catalog and you'll find about the first 60 pages are nothing but drill bits. McMaster-Carr probably has even more.
Re: Are there better drill bits than cobalt?
Posted: Wed Sep 01, 2010 8:29 pm
by Deleted User 61
Re: Are there better drill bits than cobalt?
Posted: Wed Sep 01, 2010 11:10 pm
by tholtrey
Buy a drill bit sharpener. The hardness of your bits depends on the material you are cutting. Sharpness doesn't.
Re: Are there better drill bits than cobalt?
Posted: Thu Sep 02, 2010 12:52 am
by Zombie Master
Of course, "better" is another issue. In general, harder bits are more brittle, so the harder bit may not be as good for certain jobs.
I'm aware of special application bits, and of course the market will always try to dupe you with crap. I just need to replenish my bits and am looking for some quality general duty bits for whatever job comes up.
Re: Are there better drill bits than cobalt?
Posted: Thu Sep 02, 2010 12:53 am
by Zombie Master
tholtrey wrote:Buy a drill bit sharpener. The hardness of your bits depends on the material you are cutting. Sharpness doesn't.
Can you sharpen the hard ones
economically with a drill doctor?
Re: Are there better drill bits than cobalt?
Posted: Thu Sep 02, 2010 2:58 am
by Major Softie
Zombie Master wrote:tholtrey wrote:Buy a drill bit sharpener. The hardness of your bits depends on the material you are cutting. Sharpness doesn't.
Can you sharpen the hard ones
economically with a drill doctor?
I don't know. It might sharpen cobalt, but it certainly couldn't sharpen carbide without a special wheel.
Re: Are there better drill bits than cobalt?
Posted: Thu Sep 02, 2010 3:55 am
by Zombie Master
Major Softie wrote:Zombie Master wrote:tholtrey wrote:Buy a drill bit sharpener. The hardness of your bits depends on the material you are cutting. Sharpness doesn't.
Can you sharpen the hard ones
economically with a drill doctor?
I don't know. It might sharpen cobalt, but it certainly couldn't sharpen carbide without a special wheel.
Those sharpening wheels get expensive. Question is....is it worth it to invest in a sharpening system with it's costly abrasives, or just buy new bits? I hate the throw away system. But hell, I can't seem to get a year out of a toaster oven anymore!
Re: Are there better drill bits than cobalt?
Posted: Thu Sep 02, 2010 5:51 am
by dougie
Zombie Master wrote: I hate the throw away system. But hell, I can't seem to get a year out of a toaster oven anymore!
It's not you, it's the toaster oven.
Re: Are there better drill bits than cobalt?
Posted: Thu Sep 02, 2010 7:23 am
by Curt Henry
Purchase good industrial grade drill bit, forget anything sold by home centers. I perfer Black Oxide bit.
In my job as maintenace manager I purchase hundreds of drill bits a year, worth the extra money to get good bits. Cheap bits dull quickley can break off in the matterial and in general don't work very well. You get what you pay for.
As for sharpening drill bit forget the mechanical drill sharpeners, I have yet to see one other then an industrial type that worked worth a damn. Most of the home owner sharpeners sharpen the bit with a twisted back rake, you what your back rake to be flat.
Learn to sharpen bit by hand on a grinding wheel and you will suprise how well they cut, just make sure to quench the bit offen and not allow the bit to get hot, turn the steel a color and the bit is now junk. Again you need a good wheel, most that come with bench grinders are junk. You need to dress the wheel to make sure you have good cutting (grinding) surface.
When I was in the USAF as a machinist I could sharpen a #30 bit on a wheel chucked in a home made spindle in my pnumatic drill. Holding the drill between my feet running the trigger with the toe of my boot and bent over sharpening drill bits. I sounds difficult but it was easier then the 4 mile trip off the flight line to the shop to restock my tool bag.