Drill bits

ProbablyBroke

ProbablyBroke

does not torque to spec
Joined
Nov 7, 2012
Location
Reidsville
I'm looking for advice on quality drill bits. I am not a machinist, or fabricator. But I constantly fight crappy drill bits on the weekends. I've never considered sharpening them, because most of what I have are junk in a Dewalt and Milwaukee wrapper. Where to buy? brand? Specs or rating? They will all be used on mild steel, through a drill press, corded or compact li-ion drill.
 
I sharpen mine on my grinder by hand, just don't turn them blue & watch your angle.
 
x3 but mine sometimes take 3-4 tries to sharpen it. Saw a machinist sharpen on a grinder once who knew how. Flattering!

And I will add that it has been determined per earlier discussions that someone who knows how to run a drill can make ANY bit last longer. I'm slowly learning the art...

Patience, 90 degrees if all possible and plenty of oil...
 
I have a drill doctor also and it works great for me.. except for the few times I was not paying attention and tried to sharpen the wrong angle :)
 
I've sharpened my bigger bits on my bench grinder, but I did cheat, it has a table on it that sets the right angle. a dressed stone, and a cup of water are your friends.
 
without spending the big bucks on the best drill bits...Vermont American are alright, Most of the ones sold by DeWalt and Milwaukee are okay. Just dont buy the cheapest bits!

If you dont make a living with them. Just buy the better hi speed drill bits. And don't burn em up! If you overheat them, or turn em blue drilling with them, no amount of sharpening will help because you have annealed the bit. It wont hold an edge.

Honestly, I dont buy the most expensive bits cuz we break em, or even just chip the cutting edge, far more often than I burn em up.

Drill Doctors I have used work nice, but I hand sharpen everything from 1/8" up to my 1 1/4" bits I have
 
Titanium Nitride Coated Drill Bit Set 29 Pc

Multipurpose Ruler/Gauge

I make a living drilling steel with these. I picked up my indexes back when they were in the steel case, and they went on sale for $10. I have about three boxes floating around. I've drilled miles of carbon, stainless, and even a little tool steel with these, and dammit, they're great for the money! I buy a multi-pack of some of my most-used sizes to fill holes when one shatters or I'm in too much of a hurry to sharpen them. They do take a sharpen just fine, though. I typically use a belt sander and my eyes to sharpen since the bench grinder is rarely even plugged in these days. Just don't use it much since we got a 2x72 belt grinder. Anything under about 3/8, I'll usually touch up by hand. If I have to cut one down or the edge is really screwed up, I'll use the gauge I posted to set the angle and center. Technique isn't hard to figure out, but difficult to master. On the other hand, I bought their 115 piece index in HSS black ox coating. Those have been less than impressive. Most of them are good, but occasionally you grab one that is bent or breaks way too easily. I'd like to try their cobalt index, I've heard good things, I just haven't needed it yet.

We had one job where we were drilling holes through 1" sch 120 stainless pipe. Real torture test. 27 holes through, wound up being roughly 162" total of drilled stainless. We used a decent (can't remember the brand) black ox bit. No TIN coating, no cobalt, just a HSS bit. We had a nice, rigid setup. The pipe was clamped to a large mill table. We just used a drop of proper lube, started the hole with a couple of kisses to make a dimple, then drove it on through with steady pressure. One bit drilled all that and still looked fantastic.

You don't need a bunch of oil, but using the proper oil makes a HUGE difference. I like Tap Magic for most things. A few drops will do you. For stainless, I'll have to find the brand, but it's a thick oil Fastenal sells. Incredible stuff. We used it on a 1/2" cobalt bit drilling holes in 3/8 stainless for handrails. Tried dry and burned up the first bit on three holes. Then we tried 30wt. That helped, but it still seemed hard. Tried the right lube and it was like the bit was pulling itself through the metal!
 
I've had the best luck with the bits from Dillon Supply, etc in the drill bit drawer.

Any drill bit I've purchased wrapped in a hanging package for retail sale has been crap!


Knowing how to use a drill bit goes a long way too! :)
 
I get most of my stuff from McMaster Carr, MSC, Grainger, Enco or someplace like that, where you can often choose the quality grade. McMaster doesn't tell you what brand, but it's usually always decent stuff.

I never try to save money on taps and drill bits, it's just not worth the headache if they break or just plain suck.
 
AMERICAN MADE !!!!!!.
Try MSC or similar. If your not drilling super deep screw machine length are the hottness and are 135* split point. Which allows you to start with desired finished size as long as you can push it. Sharpening ⅜ up is fairly easy once proper technique is learned. 135* split points are also available in jobber length. Good bits are kinda pricey but taken care of they are a good investment. One of the biggest problems I see is folks try to drill with to many RPMs and the wrong equipment. Those reduced shank bits like ¾" dia. and a ⅜" shank is complete BS proves the wrong equipment is being used. Once you get the feel for sharpening bits you won't forget and it'll become easy. Then you can start resharpening your holes saws. :rockon:
 
A lot of really good responses. I'm going to take a shot sharpening what I got. I imagine between bud light and YouTube I can at least bring a few back to life. And likely pick up that drill hog set after payday.
 
I have a set of these for lathe and milling machine use only:
Jobbers Drills | Travers.com

And I have about 3 or 4 of the 29 piece sets from various sources. I resharpenen them on the belt sander free hand when they get dull or break.

The lathe and mill control the speed and keep everything straight and stiff, so the bits hold up really well. I consider the 29 piece sets to be disposable bits, but all of mine I'll have at least 25 bits in each. I never use my good bits with a hand drill because it's so much harder in them.

Travers is a good source for good tooling at reasonable prices. Here's their drill sets:
http://www.travers.com/jobbers-length-twist-drill-sets/p/318545/?lite=true&keyword=drill set

And this would probably serve you well:
Jobbers Drills | Travers.com
 
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As said above, don't burn up your bits. Most "high speed" drill bits are rated for a maximum of 600RPM. Even the slowest gear on a cordless drill nowadays spins faster than that with the trigger pulled all the way. I think most people run their bits too fast and ruin them. They build up heat really fast that way and ruin the cutting edges. A second suggestion is to use cutting fluid, a small bottle will last quite a while and helps cool the cutting edge of the drill bit.

Even cheap bits can last a while if treated right. I have used a Drill Doctor with some success to clean up chipped and worn bits. I have also clamped the bits in a vise and carefully dressed the edge with a grinding disc and had good results (not always).
 
1 of the guys that used to work at the shop bought a set of snap on bits. they were the sharpest ive used. he slipped while hand tightening the chuck, half a turn of 1/2" bit took a chunk a thumb. he then had to wheel at the flats the next day still with the duct tape we put on it the night b4.
because of breakage. I usually buy cheaper bits unless its 1/2" and up. will def check out the drill dr.
 
Speed an feed is most important on bit life. More than oil or lubricant. Proper feed produces chips not friction. Heat moves with chip to some extent. No chips, no cut. No cut more heat. I hand sharpen and use mostly HSS bits for cost on mild steel and rarely use oil on anything .5 or under and use it sparsely compared to most every where else.
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These are all through drilled 9/16 with a 1/4 pilot on a drill press. Material was 1/8 wall tube. Did not sharpen the whole time or use oil.
 
I remember back in the early 2000's, MAC used to sell a set that had a lifetime warranty. Well, my tool truck did anyway. They were expensive, but when one was dull, he would trade it out for a new one. You could hand sharpen to get you by until he showed back up. That was just a fraction kit to 1/2.

OnlyOneDR said:
As said above, don't burn up your bits. Most "high speed" drill bits are rated for a maximum of 600RPM. Even the slowest gear on a cordless drill nowadays spins faster than that with the trigger pulled all the way. I think most people run their bits too fast and ruin them. They build up heat really fast that way and ruin the cutting edges. A second suggestion is to use cutting fluid, a small bottle will last quite a while and helps cool the cutting edge of the drill bit.
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Click to expand...

I pretty much agree with what you are saying about speed, but 600 RPM is no where near too fast for most drill bits. A larger one maybe. The speed is determined in SFM(surface feet per minute) and that will vary depending on dia. Of course, a cheaper bit will allow less SFM than a more expensive one. Say you wanted to run a .25 drill in cold roll steel. 3.82x100 SFM / .25 =1528 RPM. A 1/2 in bit would be, 3.82x100 /.5 = 764 RPM. That's pretty low on the spectrum using 100 SFM as a baseline for low carbon steel with a HSS drill. Obviously you can't run a hand drill in a controlled fashion like a mill or drill press, but you get the idea.
 
I agree with catfishblues on the titanium nitride coated bits.
I bought a set 7-8 years ago and still use most of them.
I also by the packs to eplace the most used ones when they break. Thats usually my fault.
Never had to re-sharpen.
IMHO the best bit for the occasional user.
The most important thing is to go slow, use oil or cutting fluid.

One thing that has helped me I haven't seen mentioned.
The pilot hole. The only time i don't drill a pilot hole is in wood, or when the hole is the same size as my pilot bits.
That tends to be the size I buy in packs also.

Matt
 
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