Most of my twist drill bits are pretty dull from doing various work on the bus. I want to replace my entire set so I actually have something that is sharp. Most of my heavy drilling should be over.
Any suggestions on what brand or where to buy?
Why not go buy a Drill Doctor and sharpen them? It has saved us a fortune in drill bits
Brian, no particular brand, but I recommend cobalt bits. There are many vendors that make and sell them.
Use some cutting oil too, helps bit last longer.
Sammy 8)
The key to drilling stainless steel is a VERY SLOW drill speed and plenty of cutting oil. Cobalt bits are the best choice. Drill Doctor should be in every shop. Jack
135 degree split point - and the drill doctor that that will shapen "split point/135" the cheaper models of the drill doctor won't do the better drills
I had a Drill Doctor and sold it. I just couldn't get the hang of it or something.
Any suggestions on where to actually buy the Colbalt bits? I am sure Home Depot and the rest are not the best, and I don't want to end up with Chinese junk.
Don't Knock the Chinese 'junk' Harbor Freight sets work quite well and sure are bargins compared to domestic. You can buy 4 sets from HF for less than one from even Home Depot. I learned how to sharpen drills on a small grinder, in my youth, so my 6" grinder is my drill doctor.
Regards
Jerry 4107 1120
They aren't junk if they work well. There are certainly Chinese drill bits that are or were junk, but I am sure there are good ones too. A lot of the "name brands" sold at Home Depot and the like are probably made in China, but for a premium price.
I'll have to try Harbor Freight.
The problem, as I understand it, is that Chinese companies not only counterfeit goods from other countries, they also counterfeit their own better quality stuff. So, although it is true that there are decent Chinese tools, you never know what you are getting until you use it. We assume that the brand name stuff that is made in China and sold at reputable stores would be genuine and have better quality control. I have bought HF wrenches that were not sized correctly. I bought a set of crescent-type wrenches thinking that you couldn't really mess them up, but the things had to be readjusted each time you touched them to a nut! If you live next door to HF and can therefore easily return stuff, it's worth a try. If not, you may end up eating a bad product or wasting a lot of time returning it.
That said, a machinist friend of mine buys only high quality brand name bits but told me that mediocre ones would be alright for me if I would keep them wet.
Belfert, the only places I found good twist drill bits has been WW Grainger or another industrial supply even the good stuff at HD and Lowes dosen't seem to be any better than HF or Northern tool fwiw
I completely agree - industrial supply house.
http://www.grainger.com/Grainger/wwg/start.shtml
http://www1.mscdirect.com/cgi/nnsrhm
Just two suggestions, I bet there are alot more even closer to you.
Regardless of the quality, most bits are ruined by improper use or unavoidable accident. This is especially true when working with SS sheet metal and unknown material behind it.
If you want top quality bits, go to an industrial supply house or machinist tool supply.
On line sellers like MSC http://www1.mscdirect.com/CGI/N2SRHI?PMSECT=516 (http://www1.mscdirect.com/CGI/N2SRHI?PMSECT=516) sell various grades from the cheap imports to the top of the line. I do metal work as a hobby and MSC is an excellent supplier. A subsidiary of MSC, Enco http://www.use-enco.com/CGI/INSRHM (http://www.use-enco.com/CGI/INSRHM) sells a lower priced line but adequate quality for working on a bus.
If you are doing a lot of rivet work, buy stub length drills in the sizes you need. You can put a lot of pressure on them without bending or breaking. Just buy a dozen for less than .50 each for double ended and throw them away when they are dull
Buy a Drill Doctor and never have dull bits. Will even sharpen broken bits. Just need to practice - then it is so easy to have sharp bits no matter what brand of bit you have. Suggest you buy the middle or higher model - the bottom of the line just does not work well. Just my humble opinion
Connel
I learned how to hand sharpen drill bits when Dad gave me a drill & a bunch of dull bits :o, so now, I buy better quality bits instead of a drill dr. 8)
A good industrial tool supply house that the local machine shops buy from is a good source.
I like the cobalt bits as they seem to last longest - especially in stainless. A good quality cutting oil is a must!
Most drill at too fast a speed. They want it to go fast. Slow down and use cutting oil as has been recommended. When you see it coil up you're doing good, smoke and it's too hot.
I have used drill bits from lots of suppliers and have also found cobalt lasts longer.
Don't fret too much, just git'er done! ;)
Paul
Some people are gifted with great eye and hand coordination if you are not. Drill Doctor, Drill doctor, Drill Doctor + Drill Chill, Drill Chill, Drill Chill or other suitable cutting fluid,you want cutting oil not lubricant!!!!! not WD40, not used motor oil. Cutting fluid is designed to help break down the metal, not lubricate. Decent drill bits, Grainger is a good source.
Think of a drill bit as a chisle wraped around a pole. With a sharp bit and the proper speed and pressure and cutting fluid the cuttings should be coming off in long thin strips. Just like if you are useing a chisle, whch you are, well sorta.
You dont have to use cutting fluid on wood :o HTH Jim
When I drilled the 1,025 holes for rivets on my bus we actually drilled at the highest possible speed. Drilling at low speed was taking forever and by accident I found that high speed seemed to work fine and was far faster. We dipped the bits into used motor oil at least twice per hole. We used about ten Cobalt drill bits from Grainger.
Enco looks like a good place to buy from. I was considering Harbor Freight, but most of their tools are junk.
The most common metal drilling bits are HHS, Cobalt and Tungsten carbide. Depend on type of material to drill and bits, you must be using the correct speed to follow thorough or you will shorten its life.
Good sharpen bit with narrow web center point will drill thorough faster than wide center web. Otherwise, pre-drill with smaller bit just large enough to allow larger one stage web bit to drill with ease. Drill Doctor can do 2-stage sharpening. Only problem with Drill Doctor is that it made of plastic trying to hold true and precise. Also to index its drill bit is more flimsy to set-up correctly. A true sharpener machine will sharpen every time, but cost many times higher. However, Drill Doctor is fine if we take more time setting up index and light grinding.
Drill Bit Speed Chart:
http://www.ibiblio.org/twa/info/drillSpeedChart.pdf
Too fast will dull because bit's cutting edges to over heat. Too slow will cause too much of heavy metal cutting to breaks bit's cutting edges.
Use cutting fluid while drilling to keep bit's cutting edge from overheating to lose temper.
http://en.wikipedia.org/wiki/Cutting_fluid
Now days you can use better cutting fluid for aluminum as well another for steel.
These are my favorite and use at General Motor Tech Center.
For aluminum... http://www.tapmagic.com/TMaluminum.htm
For steel... http://www.tapmagic.com/TMepx.htm
There are several material types of drills as well version.
Soft low carbon steel bits are used only in wood. Usually at very low price.
High Carbon steel bits are made from high carbon steel and tempered
High speed steel (HSS) is a form of tool steel where the bits are much more resistant to the effect of heat. Cost more (about double), very common and usually their base line variety in most good retailer store.
Cobalt steel alloys are variations on high speed steel which have more cobalt in them. Their main advantage is that they hold their hardness at much higher temperatures, so they are used to drill stainless steel and other hard materials.
Tungsten carbide is extremely hard, and can drill in virtually all materials while holding an edge longer than other bits. However, due to its high cost and brittleness, it is more frequently used only in smaller pieces screwed. Only machine tool supply store carry these.
Coatings
Black oxide is an inexpensive black coating. A black oxide coating provides heat resistance and lubricity.
Titanium nitride (TiN) is a very hard ceramic material, and when used to coat a high-speed steel bit (usually twist bits), can extend the cutting life by three or more times. A titanium nitride bit cannot properly be sharpened
Titanium aluminum nitride (TiAN) is another coating frequently used. It is considered superior to TiN and can extend tool life five or more times.
Titanium carbon nitride (TiCN) is another coating and is also superior to TiN.
Diamond powder is used as an abrasive, most often for cutting tile, stone, and other very hard materials.
Zirconium nitride has also been used as a drill bit coating for some Craftsman tools.
For more detail of the above: http://en.wikipedia.org/wiki/Drill_bit
FWIW
Sojourn for Christ, Jerry
One of the best tools that I have purchased while doing this bus, is "Drill Doctor"
I read the booklet that came with it, and honestly I might have well been written in Greek! I left it alone for about a year and didn't use it, then i discovered in the box under the instructions........a video tape........on how to use "Drill Doctor", in 30 minutes I sharpened every drill bit I could find, and was disappointed that there were no more..............This thing in the right hands can save you money!
My Drill Doctor came with a DVD and I don't own a DVD player. The videos are online, but I never watched them for some reason.
I did actually get one drill bit sharp with both edges even, but when we tried to drill with it, it just kinda skipped all over trying to start the hole.
Maybe watching the video would be a good place to start ???? Which model of the Drill Dr did you buy? From my experience they are paramedic proof!!!!
The BEST drills I've ever used, hands down, and cheap, $39 for 115 piece set:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=528
These drills are made of harder steel than any American counterparts, and last much longer. Don't waste your $ on TI coated... these are quite decent.
THe only hitch is that they are harder than most bits and if used improperly they tend to snap easier. None of us misuse our bits though, right? :)
Also taps and dies from Harbor tend to be MUCH better than most you can find from reputable dealers in the USA. Harbor freight might have a lot of crappy stuff, but the metallurgy of the drills and taps from drillmaster is the tops!!
If you're drilling stainless, ABSOLUTELY get some of this stuff:
http://www.westlandproducts.com/
Using "westlube" when drilling stainless makes the experience much more like drilling aluminum. It's AMAZING. In my production line, westlube changed things from 1-2 holes per drill bit (dry) to hundreds of holes per bit.
Quote from: jjrbus on April 23, 2008, 06:01:02 AM
Maybe watching the video would be a good place to start ???? Which model of the Drill Dr did you buy? From my experience they are paramedic proof!!!!
Hey!! I resemble that remark! Jack
I sold the Drill Doctor a few months after I bought it. It was the DD750X I believe. I mainly wanted it because I had to drill 1,000 holes to cover the windows. I couldn't get the Drill Doctor to work so I ended up spending about $50 on bits from Grainger.
Other than the bus, I probably wouldn't buy enough drill bits in a decade or two to pay for a Drill Doctor. Most drill bits I have purchased in the past are either broken or lost, not dull.
And the whole reason I never watched the video was the lack of a DVD player. I guess I didn't want to take the time to drive across town to watch it a friend's house.
I grew up on dairy farms, they taught me early how to sharpen them on a grinder.
(They also taught me to use safety glasses when using it.) (I think I will start a new thread concerning the use of safety googles.)
Jack
I wish I had been told that I could buy drill bits from dockside china junk supply inc instead of buying quality drill bits when I was manufacturing turbine components. I would like to see a chinese drill bit drill punch a hole in one inch thick inconel 718. Give Me a break. Cobalt drills are probably the best bet for drilling the stainless sidding on most buses. My old humble 2 centavos worth. John
When I was manufacturing equipment we tried every type of cutting fluid available. For an overall fluid for drilling either aluminum of steel and that did not leave an oily mess, we utilized RapidTap. It was heads and shoulders above any product for drilling or tapping.
http://www.mytoolstore.com/relton/rapidtap.html
Try it. It is really great.
Richard
Belfert,
Using motor oil for drilling and taping is a big mistake. The oldest and smartest machinist I know told me that motor oil would actually dull the bit. Use rapid tap. PS: I used to use motor oil because it seemed to make such sense. Too soon old!
I hope, and I mean "really hope", that you are picking up on the fact that you are the only one that can't get a Drill Dr. to work. They work gang busters...really, that good. You have to read the instructions real slow and ponder what each means and what it does. Get inside the Dr.'s head. I figured it out pretty quick but I have always had a knack. You need that sucker so knuckle down. Get a friend to walk you through. I had only the book and after you get it down it just becomes that much more clear.
I don't own a Drill Dr. and probably never will. I have a friend that has the full setup and has never been able to sharpen a single bit. I sharpen his bits for him and in gratitude he lets me sharpen all of mine and also take the thing home for a couple weeks when I need it. Just so he hassharp bits when he needs them. I am very impressed with that thing and Bubbagal is right.
Yes it does have plastic parts. They wear like iron. I must have sharpened a thousand bits with that thing, some the very largest it will take(7/8?) and gobs of them. It is still running flawlessly.
If you need one get another. Take it to the next gathering and there will be people pushing each other out of the way to take a turn showing off. Not me though, I would come back late at night ;D
Take care Belfert,
John
And another thing about drilling. lower speed, higher pressure works well. If it smokes you are toasting your bit, and ruining the temper so it never will hold a good edge again.
I have found when working with stainless if I do busrts, it cuts faster than any other method. Never go too high an RPM, start the drill, get to the RPM desired, then take my finger off the trigger and let it stop. start it again etc. Never will work harden that way. It works for drilling larger holes with circle saws too.
and yes, use that Westlube. I got some free samples, three small bottles, that have lasted me for all the stainless holes I've needed to drill.
Quote from: JohnEd on April 24, 2008, 12:31:25 AM
Belfert,
I hope, and I mean "really hope", that you are picking up on the fact that you are the only one that can't get a Drill Dr. to work. They work gang busters...really, that good.
I don't agree.
I have used them & while they may work well IF you get the right model & it ain't a dud . . . . It has always been easier for me to hand sharpen bits.
Besides, I buy the cobalt bits & don't need to sharpen them very often. ;D
I also can easily adjust the relief angle to suit the current needs.
Looks like one size doesn't fit all here.
To each their own. 8)
I guess it just depends on how your shop is equiped . . .
Kyle,
I AGREE with you. Also, I believe that people with your talent and gifts are NOT the norm. Wish you lived next door to me and I think whoever does live there is fortunate. I have tried to hand sharpen and I have such spotty success that I don't even bother anymore. I have only one eye and I think that has a bearing on my success. I can tell you that I can sharpen a bit to excellence in a dark room and blindfolded if I have that Drill Dr. in front of me. TOOLS! Ya gotta love em cause they make us all shine.
Thank you for relating your experience,
John
Quote from: JohnEd on April 24, 2008, 09:52:03 AM
Wish you lived next door to me and I think whoever does live there is fortunate.
I'm sure your neighbors are indeed fortunate :o 8) ;D
As for my neighbors, as long as they don't call code enforcement concerning the cars & trailers parked in the yard, I'm happy. ;D
A trick to hand sharpening is a good disc or belt sander & holding the bit in a drill.
With a bit of practice, anyone can sharpen drills ;D Just change the angle of the bit hitting the sander to get the relief angle you need. It helps to refresh your memory of what you're after if you have a new bit to compare your work with.
You need to go slow & don't let the bit get hot & you're all set.
The more the relief angle, the more self feeding it is. When I'm drilling large holes in thin material, I reduce the relief angle to minimize grabbing.
Kyle,
I jumbled that part. I was never talking about "my " neighbors.
I read some data on machine tools a long time ago. It dealt with the hteory of changing the relief of tools to align them with the material they were cutting. You seem to be doing that by the seat of your pants and that is nifty. I tried, honest. I had a tutor, also. couldn't make it happen with any regularity. I'll just stay jealous of you and covet my DDR.
Thanks for the info, Bud,
John
John I'm jealous also!!! These guys just dont get it. Some can run a 4 minute mile, some can throw a baseball 100 mph, I see a kid do a Rubics cube in 12 seconds with one hand!!! and some can sharpen a drill bit!!!!
Maybe we should not be envious, maybe they are freaks of nature. I can see it now at the county Fair, first you have the bearded lady, then the two headed bat boy and next the man who can sharpen a drill bit by hand ;D
JJ,
That's rich! With a creative mind like that I would want to take a close look at your bus and its systems.
Entertained,
John
Quote from: JohnEd on April 25, 2008, 10:09:59 AM
JJ,
That's rich! With a creative mind like that I would want to take a close look at your bus and its systems.
Entertained,
John
I have seen his bus & I'd gladly trade my drill sharpening skills for it! Truely amazing. I'd have never thought of some of the great things he has done with it.
I wish I'd have taken notes & measurements. ;D
JJ, the next time we meet, I'll show you how I sharpen them.
A little secret, sometimes my sharpening works well, sometimes, not so much. so I keep on trying as long as there is enough drill bit to 'sharpen'. ;D
Thanks for the nice compliments!!!! When you consider the tolerances a drill bit must be sharpened to it really is the equivalent of doing a Rubik's cube with one hand in 12 seconds.
I have been sharpening drill bits by hand for about sixty years. As I said in a previous post. below 3/16" they are not worth the time, just buy them by the dozen. From 3/16" to 3/4" they are easy to grind by hand and east to change relief angles according to the metal being drilled. Above 3/4", take them to a grinding shop and tell them what metal you are going to drill and what equipment you will be drilling with.
Using a conventional electric hand drill is just one step above a cutting torch and on large holes not as good as a plasma cutter. Consider that you need a controlled speed from 80 RPM to 20,000 RPM to have the correct speed for a set of bits drilling various metals and you can see how they ruin bits.
I too done my own sharpening since high school.
Nice about Dr Drill...it will centered the point every time. The older I get, my eyes are the same age by the way...the harder to see the finer detail.
So if you are going to trained anyone, make sure their eyes are good or use magnifiers and steady hands.
FWIW
Sojourn for Christ, Jerry (unsteady hands)
A simple question about drill bits really created quite the thread. A lot of my drilling is around the house into wood or material much easier to drill than metal.
Most of my metal drilling days on the bus are over. I also don't have any stainless except a stainless battery tray.
HARUMPH! Now you tell us. ::) ;D
John
Hello Just a thought The Delta drills with the pilot points are great drills and actually are very aggressive so that when they go thru they pull pretty hard. These drills are not conducive to the drill doctor unless you are willing to forgo the pilot point.
A friend gave me a set and I still am using some of the drills. I bought 2 more sets during the last 10 years.
A will try the worn bits onto the drill doctor to see what happens. The problem I have now is my hand gets tired and sore so iI have to space out those drilling episodes.
The drill doctor is a nice tool especially if you don't have the skills to properly use a grinder. It is a skill and if acquired at a young age it will not be forgotten. unfortunately I don't have the skill so the drill doctor is the next best thing .
happy bussin Mike