The Stovebolt Site Forums The Shop Area The Tool Chest Drill bits...............

Alright guys.........tired of breaking these blasted things. In your personal experience who has the best product out there at the best price. Looking at a Dewalt set up the local big boxes have on sale at this time. Any advise is welcomed.

Hank

I always used DeWalt and Ryobi. They seem to stay sharp longer.

That's my experience, anyway.

Lowes has a good brand that I think is a little less (Irwin). Of course SnapOn is pricey - but aren't they guaranteed not to break? Or is that just the hand tools. Anyway, Irwin seem pretty solid, and for the price less than dewalt - you probably won't cry if you do break one.

I wish I had the answer. I do know that what the machinist use is twice what I've found at the local hardware store. I a friend that was a machinist and he gave me a hand full of bits that were near the end of their use able life. Those bits would stay sharper and cut thru anything. They would cut thru bed frame like cheese most everything else would burn itself up trying.

Larry

i am no expert on anything but i have learned not to cheap out on drills. i would stay away from box store type stuff here even if it's hss. the newer drills with tin coatings are nice but i wouldn't cheap out on then either. if your drill is breaking i would reduce speed, it it won't hold a edge that's something else. i like to buy used sets of quality drills and replacements from industrial supply houses. if you can buy a drill sharpener you can make them last a long time.

Hank, I have used the Irwin bits. While not the premiere bit I have found them to be "exceptable" and not that expensive. Plus, I like driving right up to the Ace Hardware front door and walking right in to the bit section.

There prices are also good as any and most of the times beat the Lowes prices.....just today I bought a garden sprayer from Ace for $4 less than the SAME one at Lowes. Lowes wanted $15 and Ace was $12.
When you go in tell Gene/Matt/Gregg that I said hello

Thanks for the input guys. Alvin, I will compare the Irwin/ace bits. I have delt with Gene before. I will pick up a few of that brand as replacements and see how they work this weekend.

Hank

Just out of curiosity, what are you drilling? The material that you're drilling might be part of the problem if you're not using the proper type of bit for the material you're working with.
Personal opinion, I primarily use cobalt bits. More pricey than reqular HSS and TiN coated, but they last much longer and hold up very well to abrasive material like cast iron. I get mine from the local Sears store.

Get a Drill Doctor, best money ever spent on drilling,
Scott

Longbox,

Sheet metal, drilled and tapped a stud I broke in the engine block..broke the bit doing it ....automotive shop stuff.

Hank

For a few extra bucks high performance drills/taps sold by industrial distributors will vastly outperform retail hobby stuff. Try one of these for comparison:

http://osgtool.com/product_list.asp?type=DRILL&type2=Jobbers

You can find a place that sells them here:

http://www.osgtool.com/search_distrib.asp

These work relatively well removing drills and taps:

http://omegadrill.com/

Here is some text I found (plagerized) on line that kind of describes bits and their use.

Drill bits undergo a lot of stress when drilling a hole. The high-speed rotation of drill bits generates friction that, in turn, generates heat. The friction between drill bit and material leaves drill bits slightly duller after each use. The heating and cooling of the drill bit material can weaken the internal structure of the bit over time.

The Common Drill Bit
Common home repair drill bits are made of steel or High Speed Steel (HSS). Although inexpensive, common steel drill bits tend to wear out or break very quickly. HSS drill bits last longer than steel, but are more expensive. These types of drill bits are most effective when used on wood, drywall or plastics.

A Bit Stronger
Coated drill bits use another, harder material to coat steel or HSS drill bits. Titanium carbide or titanium nitride coatings can increase the lifespan of a drill bit by two to three times. These types of drill bits are useful when drilling hardwoods or thin metals.

When The Going Gets Tough
Carbide drill bits are among the strongest drill bits available for home use. Carbide drill bits are more expensive than steel or titanium coated drill bits, but will last longer and stay sharper.

Carbide drill bits are absolutely necessary when drilling stainless steel or other high-density materials. No other drill bit can handle the job.

Regardless of the material that you usually drill, a carbide drill bit will last up to 25 times longer than a common steel bit. This can make carbide drill bits an economical choice for woodworking, furniture building or other large-scale projects.

When cutting dense material, use a cutting lubricant to avoid generating excessive heat. Overheating a carbide drill bit will shorten its lifespan. Always let the drill bit do the work. Applying too much pressure will quickly dull your drill bit.

Not entirely true. This is a page from the above link:

NEXUS Drills

For years the name in stainless steel drilling has been synonymous with OSG's EX-SUS-GOLD drills. Well OSG has raised the bar with the next evolution of Vanadium High Speed Drills, the NEXUS. This latest product from OSG features a unique 40 degree helix, coupled with a sharp thinning point designed to; reduce work hardening, improve finish, and eliminate exit burrs. The NEXUS also features WD1™, OSG's latest new development in coating technology for drills. Higher oxidation temperatures, better adhesion strength, and elevated hardness allow the NEXUS to run faster than its predecessor without any lost tool life. NEXUS is designed to improve efficiency through faster speeds and improve tap performance by reducing work hardening in the hole.


Improper cutting speed is where tool life is most wasted and can be determined by the following formula:

CS (cutting speed) X 3.82 / DIA. = RPM

30 sfm for stainless and 80 for mild steel would be good starting points when hand drilling. For example a 5/16” drill in stainless steel should be spinning 367 RPM (+- 50 RPM) or 979 RPM in mild steels. By ignoring this and spinning much faster excessive heat is generated which is quickly fatal to the temper of the cutting edge. The quality of the drill/tap ultimately decides the SFM the tool can be run at so with cheap stuff going slow is the best defense to preserve tool life. Lubrication never hurts and even a drop of motor oil will help but a can of Rapid tap or similar product will pay for itself many times over in keeping cutting tools sharp. Here’s a chart with recommended surface feet per minute for various materials:


http://www.winsloweng.com/articles/drillChart_content.htm

I'm with Curt - my biz has lots of SS equipment, much of it purpose-built by me, and the most important thing for working it is proper speed AND pressure, too light a pressure is the same as too high a speed .... as Scott points out, get a Drill Doctor and keep your bits in shape, including the proper pitched tip for the purpose, and you'll save frustration .... best way to prevent breaking bits is to use them properly

Bill

Thanks for the information on the bits guys. I was looking for what you are using or have found to be effective. I don't need info. on pressure and speed causing breakage, etc. I do appreciate your opinion, but share with me what product/ brand you have found to be most effective usage and cost wise. Thanks,

Hank

i think you can get a 1/16 to 1/2 in 64ths hss, morse brand set, for about $80, cobalt for about $150. the industrial import set 1/16 to 1/2 in 64th $40 for hss, $75 for cobalt. tin coated hss was in between. that's what they were running a couple of years ago. let me say i have never bought a brand new set in my life. i like to hunt for used quality sets and resharped/ buy single replacements. that works the best for me. i have also found the industrial import single replacement drills i have bought have held up extreamly well. there is a world of difference in them and box store type drills, at least in my limited experience. i am someone who has broken a lot of drills and still do on occasion. the harder they are the easier they are to break. i think they make some surface treated 118deg drils that might be less prone to breakage. someday i will be rich enough to buy the big combo sets in all hss, tin, and cobalt; prob after i don't have any more holes to drill.

I thought I did that. Here's a few more comparable ones:

http://www.precisiontwistdrill.com/catalog/get_page.asp?image=products&page=24

http://www.yg1usa.com/feature/item_...;pre=&pre2=&name=GOLD-P%20DRILLS

http://www.cutting-tool-supply.com/ClevelandTwistDrill/Drills/HP/Home.htm

I think a 1/16 bit has a life span of about 3 seconds.

Just Kidding!

But I notice they break pretty easy.

Am I too heavy-handed, or is it just the quality of the bit?

Thanks!

I have many "sets" of drill bits that all the small ones are broken. anything less than 1/8" is a goner as soon as I load it in the drill.

I know someone will shoot this down,but I have always had good luck buying bits at Sears.They are reasonably priced and stay sharp quite a while.

another thought, you might try the screw machine style drills rather than jobber lenth on the smaller diam drills. being shorter, i think they break less on me; but it might just be my imagination.

I recently machined a 316 stainless steel attenuator that required 11,000 1/16” diameter thru holes and the best performer in that application was OSG at around 250 holes per drill or about 1 hour of run time which I thought reasonable.

Thanks Curt, you sure did. I appreciate the info. Here is what I was referencing...."proper speed AND pressure, too light a pressure is the same as too high a speed".

Hank

Are you guys aware that drill bits can be easily resharpened freehand on a bench grinder. I do it all the time. Discarding a dull drill is like discarding a dull pencil.

If any of you know a machinist, ask him to demonstrate the technique.

[email protected]

i have done it on larger drills above 3/4" because they were too big for my drill dr. they did ok, cut better after than before. i think you have to be careful to keep the center on center and grind a relief in, and of course watch your angle. i have a old style drill gage, that helps. but you don't want to cut oversize holes with a off center drill. might take a little trial and error to get just right. i would hate to try i on the smaller ones. i'm not saying you are wrong or anything i guess it just depends on the person doing it. my grandfather used to sharpen all his drills by hand and i hate to say a exact job sure cuts a lot better.

There is several tricks when using drill bits on sheet metal one always us a good lubricant that won't fly off your metal. They make some special lubs for S/S which keeps the bits cool but when the bit starts to get dull or you do not keep the right pressure against the S/S you will work harden it. When you get older your eyes are not as sharp as they used to be. For bits HSS when sharping them they have can't remember the taper 59 degrees comes to mind but take two standard american nuts and put them together and that is the correct taper to sharpen them at. You can refer to this angle from 1/16" to 3" drill bits. When you free sharpen on a grinder you can see if you ground the taper and relief correctly.

While we are on the subject of cutting holes a lot of you use Hole Saws. A neet way to keep the saw blade teeth cool is use Crisco Lard like your wife or mom used to use it works great and the Hole Saw Last a lot longer.
62Blue
Don

Ahh yes on sharpening drill bits.For years I sharpened them on a grinding wheel,then one Christmas I received a Drill Doctor,and it is one nice piece of equipment.I can get the Drill Doctor out turn the radio to a country music station and sharpen a coffee can full of bits in about one hour.

Dale, I used to use a drill grinding gadget also. Then I took an evening adult education machine shop class and the instructor showed me how to sharpen drills freehand. It's much faster than the drill grinding gadget and at age 65 I can still see drill points down to about 3/32". I use the drill sharpening gadget to repoint my tig welder tungsetns now.

Yar.I guess its a matter of personal opinion.I am 72, and have sharpened many bits freehand on a grinding wheel.Maybe its just the fact,that I can sit down at my workbench and listen to some good tunes while using the Drill Doctor.Sorta like taking a one hour break.And yeah,an old machinist friend taught me how to sharpen them freehand.

.... well, let me be the first to say...I've tried to hand sharpen them and its just not me. I usually make them worst. Dang it, some guys seem to have all the real talent! I'm jealous.

i'm jelous too. not just of the fact someone can sharpen them better and faster by hand, but that you all have a old machinist friend. i don't even have a young machinist friend let alone a old one.

Achipmunk, I'd like to suggest that you let someone demonstrate the technique. Then you'll know what the basics are. In drill grinding, the basics are really basic: correct chisel point angle, correct flute angle and clearance and equal flute length. There is a simple drill gauge that is used to check these things. Your eye is incredibly accurate and with a little practice the gauge just confirms what your eye already knows.

I can understand the difficulty you are having if you're trying to teach yourself. I tried to teach myself gas and tig welding and that was a lost cause. Then I had the correct technique demonstrated and after that practicing (a lot of practicing in the case of tig) brought steady improvement. That may not be a good example because welding is much more complicated than drill point grinding.

We are a gadget society and so many of those gadgets are completely unnecessary. The best example I can think of is a talking TV screen in a car dashboard instead of a good old map.

Alvin, if you find a teacher for the bit grinding, I'd like a seat in that class too.

For making holes in sheetmetal, Hougen bits are the way to go.

Here’s a good article on the basics of drill pointing:

http://www.mmsonline.com/articles/choose-the-best-drill-point-geometry

Here’s a class:

http://www.toolingu.com/class-200247-drill-geometry.html

And here’s a discussion on sharpening by hand:

http://www.cnczone.com/forums/showthread.php?threadid=22760

Thanks for the link and the spell check or spellcheck whatever works for ya!

Seems to me that if you are breaking drill bits you are doing something wrong.I usually buy them from Sears and they are reasonably priced.I have small bits in my shop that are 30 to 40 yrs.old and still doing a fine job. And oh yeah I have a drill doctor which I use to keep them sharp.Just the small ones as I do the larger bits freehand on a grinding wheel.