M35 and M42 drill bits

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Dec 31, 2017
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SE British Columbia, Canada
I’d like to have one good set of drill bits for drilling steel. So far I’ve seen recommendations for M42 bits. Does anyone have a preference for brands or any other suggestions on M35 vs M42 bits?
 
Like you said M42 is harder and more brittle they will snap with just a small amount of flexing, M35 are a bit more tolerant of flex and still hard enough to handle hardened metals. A good HSS set will do most jobs just fine and are easier to sharpen. Carbide drills are super hard and not the best for a drill press either they are better in a lathe, they will not tolerate the slightest amount flex without shattering.
 
I searched Amazon and found Bosch M42 bits but could not find Bosch M35. However I found these Bosch CO21 bits. Any idea what they are about?

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I believe they are M41 just a 21 piece set. You can use M42 but using the smaller sizes can be hairy. I had to drill out some grade12.9 studs and needed M42, I broke 4 small bits on each stud, I buy the small ones in 10 packs.
 
For a hand drill and even your average vertical mill people get way too concerned with "the best" drill bits.

Buy non-Chinese HSS and learn to sharpen. Everyone seems to think there's a magical bit that will never dull and never break. If you believe that I've got some engine oil and a filter that will never need changed regardless of mileage or hours. You can order at ColoradoOceanFrontProperty dot com!
 
For a hand drill and even your average vertical mill people get way too concerned with "the best" drill bits.

Buy non-Chinese HSS and learn to sharpen. Everyone seems to think there's a magical bit that will never dull and never break. If you believe that I've got some engine oil and a filter that will never need changed regardless of mileage or hours. You can order at ColoradoOceanFrontProperty dot com!
I don’t think anyone said they was a magical bit out there, but Cobalt bits blow the doors off HSS when drilling steel. It’s just a matter of picking the type to match the job. A small concentration change in cobalt makes a bit difference.

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Funny thing - just the other day I needed to drill a small hole in a wrench. I managed to drill a small 1/16 or so hole with a cheap old northern tool bit believe it or not. However, I then realized I needed it bigger. The two slightly larger bits went through the hole, but did NOT drill it any larger. 😁
 
OP, have you checked out the tools available at McMaster - Carr.

They have an online catalog. If you ever need any tool or bolt or most other general mechanical things always remember to check them out.
 
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