Drill Bits

Cobalt is the only bit that will drill stainless. I agree cutting oil dramatically extends the life of bits but any coolant is better than nothing.a cup of water or the natural lubricant that you always have with you (spit).
 
I want to thank everyone for their reply. May I explain. I just treated myself to a new drill press as my old one is from the 20's. It was on my bucket list and near the bottom I might add. As an 80 year old I don't expect to be drilling on a daily basis. From your advice I just ordered a set of cobalt 135* drill bits, as the few cobalt bits I now have, with a little oil are as good as new. Again thanks for your advice. Jack
 
jhowes said:
I want to thank everyone for their reply. May I explain. I just treated myself to a new drill press as my old one is from the 20's. It was on my bucket list and near the bottom I might add. As an 80 year old I don't expect to be drilling on a daily basis. From your advice I just ordered a set of cobalt 135* drill bits, as the few cobalt bits I now have, with a little oil are as good as new. Again thanks for your advice. Jack
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The best way to sharpen carbide drill bits is to sharpen them either on the Green Grinding wheel or a on the diamond grinder wheel. To sharpen them on anything else will easily chip up their carbide cutting faces. The green grinding wheels are real soft and they wear away rapidly. The diamond wheel is long lasting but it is very expensive. In my machine shop I use high speed drill bits for almost everything. I use the carbide drill bits when the going gets rough as in drilling really hard stuff. i.e. hardened tool steel, broken off taps. A full box of high speed drill bits from 1/8" through 1/2" will give most hobby people the best service. They are affordable, easy to sharpen on any grinding wheel, and easy to find replacements for them.
 
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I agree high speed steel work just fine. That is what we used in out plant 95 percent of the time. Just do not get blue chips, if you do you are running the bit to fast and you are in trouble.
 
SSsssteamer said:
The best way to sharpen cobalt drill bits is to sharpen them either on the Green Grinding wheel or a on the diamond grinder wheel. To sharpen them on anything else will easily chip up their cobalt cutting faces. The green grinding wheels are real soft and they wear away rapidly. The diamond wheel is long lasting but it is very expensive. In my machine shop I use high speed drill bits for almost everything. I use the cobalt drill bits when the going gets rough as in drilling really hard stuff. i.e. hardened tool steel, broken off taps. A full box of high speed drill bits from 1/8" through 1/2" will give most hobby people the best service. They are affordable, easy to sharpen on any grinding wheel, and easy to find replacements for them.
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I think you have cobalt and carbide mixed up.
 
Speaking of HF, I have my Dad's 20+ year old HF drill press and band saw yes made in China but good enough for the home users.
 
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