Drill Bits

[Tim Crosby]

Is there a brand of drill bits, fractional and numbered, that is better than the rest? I understand that speed, pressure, lubrication and material being drilled can shorten their life but I swear I go thru them like jewelers saw blades no matter what the brand.

Thanks, Tim C

[Randall Steffy]

Tim,
Drill bits have evolved to be pretty application or job specific. If you shop Manhattan Supply Co.-MSC, or similar, you will see a selection that may make your head spin.
For jobber length drills, I tend to prefer bright finish, or polished, with split point. Cobalt alloy gives you added wear, as do specific coatings, all of which tend to again be application specific and add to the sticker shock.
But above all, you get what you pay for. However you can also waste money on bells and whistles you do not necessarily need. I buy Precision Twist Drill, Chicago-Latrobe, Cleveland, and on occasion imports if cost is the primary concern.
If you fit the drill to the job, use appropriate speed and feed, correct lubricant, you should have the same set for many projects.
The experts here, of which there are many more experienced than myself, would likely make suggestions if you were specific as to your present challenge.

[J Shingler]

I have had good luck with ENCO as a fast economical choice.
http://www.use-enco.com/CGI/INSRAR?PMSECT=0000000618
I usually choose the made in USA HSS.
Jeff

[flehto]

Do you break a lot of them or are you running them too fast? Do you sharpen any? I use HSS drill bits and my selection has lasted 25 years and  need sharpening very rarely. A little oil  helps w/ the cutting and chip clearing. The small diameter bits require a "light" hand, proper speed and a lot of chip clearing. Sometimes if a drill isn't sharpened properly a lot of heat is generated which will soften a carbon drill and  requires a lot of force which results in a broken drill.  Drills for brass need to have the cutting lip "squared" so they don't grab and break or worse.....Fred

[P.W.Berkuta]

The enemy of drill bit longevity is heat and friction  . As long as you are not drilling fiber glass composites, exotic metals, or are running the speed way too fast for the material speed & feed rate and not using a proper coolant for the application the standard H.S.S drill bits from the leading manufacturers should serve you well. They WILL need to be sharpened to keep them performing so you do need to sharpen them. First for the sharpening part I do like the Drill Doctor with the ability to sharpen both 118 degree & 135 degree split points. Those 135 split points "blow" through mild steel like greased lighting. You can buy the cheaper import drill bits and save yourself  50 cents a bit  and throw them away after 3 uses (or sharpen them) or buy Cleveland or other top brand which will hold an edge longer (but still need to be sharpened).

[George F.]

My son gave me a drill doctor. They do a fast and good job, only draw back is it won't handle anything smaller than 3/32". For the smaller bits I use a diamond plate and do it manually.   ...Geo.

[billd]

If your using a hand drill, bits will not last near as long as with a drill press. Most poeple run too slow feeds because they can't push the drill hard enough and keep it straight, meaning they're in the the metal too long. To slow of a feed is as bad as to fast. Also a hand drill doesn't have the rigidity of a drill press. A small flex of the bit can cause a small chip on the flute but by the time you finish drilling the hole the chip is worn away and it looks like it's just burned up.

In our shop we use mostly cobalt for steels and stainless and bright finish fast twist or parabolic for aluminum. That's with a drill press or a milling machine, not by hand.

As far as brand, Cleveland, PTD, Chicago/Latrobe are all good. A split point cuts much easier than a standard 118' point, but split points are not available in all configurations.

Bill

[Tim Crosby]

  I seem to break a lot of small bits while drilling metals and it is usually just as it breaks thru. I have a hand drill, drill press and a lathe that I use a Jacobs chuck in. It's probably just me, to fast, to quick a feed, to much pressure, I just need to do a little retraining.
  Thanks for the answers and suggestions.

Tim C.

[Elnathan]

Just out of curiosity, are higher-grade twist bits less inclined to wander off the mark when first starting the hole in wood? I have had a terrible time over the last year or so with twist bits wandering off the mark before biting into the wood, even when I have started the hole with an awl or punched a dimple with a centerpunch.

[billd]

A split point drill will find it's own center better than a regular drill bit, but most are 135' vs a 118' for a standard jobber drill. This means the point on a split point drill has a shallower angle which sometimes defeats the purpose.  Small bits have a bad habit of following the grain of the wood, that's why wood bits have a pilot. I don't know of any wood drills small enough for our purposes.

Bill

[George F.]

Brad point bits go down to 1/16"

[billd]

Good to know, I never saw them that small.