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A good set of cobalt twist drills?? - Printable Version

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A good set of cobalt twist drills?? - jgourlay - 12-28-2016

I have a set of cobalt twist drills I bought for a 'good' price a number of years ago.    I've come to the conclusion that the 1/8", 3/16", 1/4", 3/8" and 1/2" were probably properly heat treated but that the rest may not have been.  Evidence:  those are sharp and stay sharp through long use in 'mild steel'.  When resharpened, they last.

The rest, however, seem to dull at the slightest use in any ferrous metal.  When resharpened, they last through maybe 1/8" and then dull again.

Can anyone recommend a good set of twist drills, preferably cobalt but HSS okay, that's not one of the $230 sets you see industrial supply sites?


RE: A good set of cobalt twist drills?? - meackerman - 12-28-2016

http://www.bridgecitytools.com/blog/2010/10/25/5-for-a-18-twist-drill-only-in-america/


RE: A good set of cobalt twist drills?? - Herb G - 12-28-2016

Norsemen bits are top of the line quality, and price wise too.


RE: A good set of cobalt twist drills?? - Robert Adams - 12-28-2016

Not really. You can get decent bits from precision twist but better than that is going to be $200+. Good drill bits are just expensive. However the best metric wood brad point bits I have used are a set that were made in the cccp. Small set and they were dirt cheap but they are very sharp even today after lots of use. 

   https://www.amazon.com/Precision-Twist-C29R10CO-Cobalt-Jobber/dp/B00075NWNU


RE: A good set of cobalt twist drills?? - fredhargis - 12-28-2016

(12-28-2016, 01:27 PM)Robert Adams Wrote: Not really. You can get decent bits from precision twist but better than that is going to be $200+. Good drill bits are just expensive.

That's kind of my opinion as well, a good set lasts a very long time though.


RE: A good set of cobalt twist drills?? - Brian in sunny FL - 12-28-2016

I have some Norseman sets but just regular HSS.

https://www.holbren.com/split-point-drill-bits/

Next time I order, I will probably add the 135 degree Hi-Moly versions which use the same metal as the Brad Points I have listed and said to outlast cobalt.


RE: A good set of cobalt twist drills?? - meackerman - 12-28-2016

what's the 29 piece in the Hi-Moly retail for?


RE: A good set of cobalt twist drills?? - Arlin Eastman - 12-28-2016

I am not going to recommend a bit but a few other things hard won while working in the military

1. when drilling steel slow speed heavy feed.
2. if drilling more then 1/8" use lube to allow the bit to cut better and cooler
3. If you are drilling Aluminum it is high speed light feed

I do not remember the others right now but the first two are the most important for any bits

Also you do not have to buy a whole set just the ones you use all the time and replace them even split tip does not last forever


RE: A good set of cobalt twist drills?? - Brian in sunny FL - 12-28-2016

Retail is $164.90 but I would probably put them up at $99 with free shipping, no discounts though.


RE: A good set of cobalt twist drills?? - Robert Adams - 12-28-2016

(12-28-2016, 05:34 PM)Brian in sunny FL Wrote: Retail is $164.90 but I would probably put them up at $99 with free shipping, no discounts though.

Not a bad deal for those at all Brian.