How To Sharpen A Twist Drill
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- Опубликовано: 27 июн 2016
- If your drill isn't sharp, you're not going to be doing much cutting, right? This video will go over the important geometries of twist drills before getting straight to the point and showing you how to sharpen one.
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Thanks Don But I feel you needed to explain that the blue colour of the "worn" drill, indicates that the hardness of the drill has been severely compromised and that grinding back to clean metal , was necessary to achieve original hardness. Also, during grinding back I would have been constantly quenching in cold water, again to prevent the drill losing hardness.
Thanks Don, for showing us how to rescue of a totally ruined drill bit. I sharpen my slightly dull drills on a medium to fine grit sanding belt using a drill gauge to check angles and centering. I then thin the center chisel edge to minimum width on the grinder wheel as shown. Lots of perfectly good drills are thrown away due to lack of knowledge on how to sharpen them.
When I served my apprentice (tool and die) at General electric, we had an older gentleman at that time that sharpened all drills, end mill and etc: in the shop by hand and there never was a problem with any of his work. As time goes by the golden oldie tool guys will be gone and what will be left will be nay-sayers.
Couldn't agree more. There's certainly an art to it that is dying out, but thankfully there are quality drill sharpeners out there that will do the job quickly and accurately.
when i hand grind a drill, i first do the 12 degree front clearance with the 59 degrree angle sighting it with a cupped hand over it up against the light to create a shadow of the drill point, checking the angles and lip lengths are the same on both sides. then i give it the secondry clearance starting the grind from the back edge and rolling it round to the 12 degree front clearance leaving a land equivalent of the side land of the drill, thin point if needed. the drill usually cuts within a thou of it's self. i use them on wickman multi spindle auto's and bsa single spindle auto's. been doing it that way since 1976.
My Dad taught me a very slightly different method when I was a boy in the '50's. Worked like a charm since then. An old tool grinder showed me how to sharpen 1/8 and smaller drills with a slip stone, even thin the web and back off the lip angle. Good stuff. Thanks for kindling the memories.
I don't recall if you did a video on how to care for and clean micrometers where the different basic head designs are treated individually. Maybe include segments on how they are calibrated and what to guard against when buying used mikes. You are ideal for the task. You got the knowhow and major cred in our little world of part manufacture.
I don't believe we have, we've made a note of it and we'll look into it in the future. Thanks for the suggestion.
Don, Your videos are always excellent and worth a visit. Thanks for all the time it takes to produce these. Jim
Glad you enjoy them, thanks for watching.
That a very interesting and important thematic right there. In my training here in germany i have been told to use a 130 degree angle not only for hard steels but also for aluminum. I was wondering that the bit changed colour when grinded. I was told never to overheat the drill when grinding because it would weaken. The heat though is indicated by the coulour change. Great video and great content in general! As a youngster i have learned to listen closely to what the oldsters got to teach.
I just Love the way you teach us, Thank You Sr, Thankyou VERY MUCH!
Great video! One of first things my machine shop instructor taught me was how to poperly sharpen drill bits and also how to make cutting tools from tool steel blanks for lathe work. Great experience!
Best video I seen! Free hand sharpening, no need for jigs, just a proctor, excellent!
I've found that once I try sharpening drills off-hand below about 0.150" diameter I have a lot of trouble getting the chisel point thinned to the correct size. A drill grinding fixture or machine is about the only way I get good results in the smaller sizes. I don't even bother with drills smaller than 1/16" even if a drill grinder is available.
When sharpening drills larger than 3/4" or so, I use a belt sander to finish the cutting edges and finish generating the relief. A good square corner on the bench grinder wheel does an excellent job of thinning the web and reducing the cutting angle on the face of the cutting edge. This gives more support to the edge and helps cutting edge life.
What wasn't stressed in the video is that the relief is a complicated surface. You can see this on a new large drill. It isn't just a plain conical surface. As you get closer to the center of the drill's center chisel point, note that the clearance angle becomes steeper and steeper. This is because as the drill advances into the work the center of the drill has to advance at a greater rate vs. the small diameter than the outside diameter does. You can duplicate this when sharpening the drill off-hand. As you rotate the drill against the grinding wheel, swing the drill out from the 59 degree angle so that the drill describes a spiral motion. This generates more clearance for the cutting edge as you get closer to the center of the drill.
Sharpening drills is a complex operation and no one method is good for every situation. When I worked at Champion Aviation there was need for deep drilling jet engine igniters made from Hastaloy. The only drills that worked came from a manufacturer in Germany. Before use we sent them to a guy in Ohio who resharpened them in his basement shop. The drills were run at about 35sfpm and it was slow going.
One of the best how to do it, on sharpening drills I have watched. The magnification shots were very instructive.
Thank you, glad you enjoy it.
Thanks again for the great tutorial. Proper and effective bit sharpening has always evaded me. Looks like I'm trying again with some new guidance.
I always enjoy these videos, very informative! Thank you!
Glad you enjoyed it, thanks for the comment.
thanks for a very good illustration. easy to understand and after i wrecked a drill with stainlesssteel, i could make it work again with your instruction
Thanks for showing the Millennials how to sharpen a drill bit. I'm really not surprised by the ignorance in some of their comments, but maybe a few up an coming machinists will pay attention and learn something from you.
Our trade is nearly dead due to the greedy corporations sending the work to different countries for cheap labor. There aren't many skilled machinists left to teach the trade to young men and women in the American Workforce.
Marking a line of the tool rest is a great idea for setting the angle. I learned something from you today. THANK YOU SIR.
I love the factory tours. Please give us more!
Noted, we'll work on it. Thanks for the comment.
Great video. Don,you remind me of the tool makers I served under in the late 60's.then I had to quit 14 months from my card,to go in the Navy.You know the draft.Keep up the great videos.
Thanks for the comment, we'll keep 'em coming.
Great video, I wish there was such a thing as youtube when I was a teenager. Getting a look into a shop with expert instruction on what we are seeing is invaluable. I truly think you are inspiring a new generation of craftsman.
A trick I was shown when first struggling to resharpen a bit was to take two nuts and put them together side by side and that angle should be close to the final bit when sharpened.
Thanks for these videos, they are both entertaining and educational.
You're welcome, and thank you for the support.
American Gunsmith ran a series recently about gun drills that was fascinating. I wish it were available online because it was a great read.
Best video on this subject I've seen to date!
I used to tell my industrial maintenance students that once you learn how to sharpen a drill and after using a sharp drill you’ll never use a dull but again. Of all the things I leaned in my machinist part of my trade school, the drill sharpening I use all the time.
Great knowledge, people need to stArt with your video before going to the others !
I have been sharpening drills for over 50 years, now I know what I was dong wrong!! I cannot thank you enough!
Thank you for watching!
Thanks Don! Great camera angles on this one! 😃👍
You're welcome, and thank you for the comment.
To all who complained about not using a drill grinder...back when I started out, first shop I worked in the "old man" machinist had me sharpen drill bits by hand until I could do it right, by eye. Literally spent every day for several weeks until I was somewhat proficient. Was a PITA for sure, but taught me a ton about proper cutting tool geometry. I am now a Mechanical Engineer, but I still cringe when I see people on the shop floor use a drill grinder (and don't know what a sharp drill should look like) and complain that the machine won't sharpen a drill properly....
Thanks I always learn from your videos.
You're welcome
Learned the trick to really sharpen a drill. Like how you showed each step on camera.
Thanks for tutorial. I enjoyed reviewing it.
If you want to learn how to sharpen your drill bits watch this video I have tried to sharpen drills in the past with bad results I looked at drill sharpeners and drill jigs but all had mixed reviews I came across this video he explained everything so well I bought a cheep engineers protractor and after some practice I sharpened all my drill sets the mark on the grinder rest is really helpful thanks for a great video !
Thank you for the kind remarks.
THIS makes sense, right on! I got in a squabble with my husband about the heel, hah! I was right. Thanks so much. My bits turned out great, no annealing from too much heat makes all the diff!
Great video for anyone wanting to know the the fundamentals of drill sharpening.
Thank you, I appreciate the support.
I have been sharpening drills since I was eight with just a bench grinder freehand. Now Im old my eyes are bad and the arthritis is a problem. Every thing is now much more difficult so ...this old dog needs some new tricks and a drill doctor does not seem to be the way to go. Plus I have now got lots of split point drills and this is even adding more layers of old man difficulties. I really like all of your videos so now Im even going to set up to put three flats on all the shanks too.
Best drill bit sharpening tutorial I've seen yet
Wow, thanks!
Best I've seen and I've actually learned something here! Thank you very much
Thank you for watching.
Great video, thank you for all you do. I have a video suggestion, dressing a concave radius in a wheel and then properly grinding that radius on a part. thank you
Great idea, it's in our books. We'll see what we can do.
Great Video.
It should be fun to see the drill working.
Thumbs up.
We'll deliver soon. Thanks for the comment.
removed a lot misinformation from some hacks that have told me "yer doing it wrong" thanks Don B.
This is a great channel, thanks for all the info you share!
We're glad you enjoy it, thanks again for watching!
During this "STAY AT HOME" business I can think of no better companion than Mr.DonBailey!Thanks again for these videos!
Good to see that you saved that drill, most people will throw it away.
Yep, I see people break a bit at w*rk or wherever; they go to throw it out and I say "Wait! That's a new stubby bit!!"
Whoa, free hand drill sharpening! I figured for sure you would show us some awesome fixture or jig to align it within "a couple of tenths" but this is so practical it's awesome (-8
That's the goal here! Thanks for the comment, glad you enjoyed it.
appreciate your time. that is all we have, really, is time.
That's heavy, man. ;) Thanks for taking some time to watch our content, we really appreciate it. Also, thanks for the deep thought of the day.
Nice video you kinda do what I do to sharpen a bit. I was taught a long time ago by some salty old maintenance mechanics how to sharpen bits. The best I can describe it is like learning to hit a golf ball. It doesn't look hard until you try. Once you hit it then you have to figure out how to hit it correctly. Same with sharpening a bit. It Takes practice and feel, but once you figure it out its like riding a bike. Keep water by your grinder stone, don't over heat it. If your sharpening a dull bit you don't need a lot of pressure, hardly any. If your putting a new cutting edge on a damaged bit establish your center point and angle first, once you have that, it takes a little time to grind your flank below your cutting tip.
This video helped me. Thanks Don
You're welcome, thanks again for watching. We really appreciate it.
Great video - I will try following your instructions. I do mine freehand on a normal grinder, but I can never get the point centered properly and they always end up drilling oversized holes. So I can only use my re-sharpened ones for rough work.
You can do it!
Hi Mr, Bailey, Love the videos. I recently purchased a Ward Maxigrind don't have a clue how to use it yet, but it will come to me. There are not many videos on tool and cutter grinders, if you have the opportunity I would love to see whats inside your head regarding them. I know they are quite versatile. Thanks.
I've made a note of it and will consider. Thanks again for watching!
Ahh yes left handed drill bits. As an Industrial Mechanic I use them quite often for broken bolts, a must have!
Indeed!
don't forget about the easy outs when the lefty didn't have enough grab to pull out the broken screw.
Thanks, as always I learned a lot.
I'm glad you enjoyed it, thanks for the comment.
thank you very much, I have tried to learn this skill for some time but the detail always put me off, you lesson was a real EUREKA moment. very well done sir
Glad you were able to take something away from it! Thanks again for watching.
Thanks, good info
I would love to see how you sharpen small drills. When Ip asked the same question with another RUclips video maker he said you don't bother, just throw them away and but a new one. I did buy some small carbide drills that are normally used in dental work that are quite expensive.
Awesome video. Thanks. I don’t want to rely on a drill doctor and I like being able to fix things myself.
Thanks for the video!
Maybe you can make a video out of this: How do you make a tapered screw on a lathe? Some time back I had to make a copy of a 16th century wood screw (in stainless steel), it was pretty tough and I ended up filing the thread by hand. How would you have done it?
We'll look into it. Honestly, I'm not sure how I would do that at the moment.
Beautifully done, could you show sharpening a carbide drill with a green wheel? I've tried many times and always default to going to our rather tired diamond wheel.
We can give it a try and see how it goes.
+SuburbanTool Inc that would be awesome. Thank you.
What an idea sir Ji....
I'd like to see you make a flat spiral like the one inside a three jaw chuck, thank you in advance. Thank you for sharing!
Noted, this could be a good challenge. Thanks for the comment.
great stuff Don. these videos would make great brief tutorials for both apprentices and hobby machinists alike....not to mention the guys in the toolroom who can't sharpen a drill :-D
Glad you enjoyed it, thanks for the comment.
Thank you for calling it by it's right name.
we had an old machine shop teacher who fixed planes on navy ships during WWII He taught us how to sharpen drill bits. many of the students hated him, but I thought he was great. also taught us discipline
Thanks, I learned!
this guy is pretty much the ONLY one I pay attention to...thanks Don!!!
You're welcome! Thank you for watching.
Great Video !
Great video! From theory to practice, great closeups and magnification. Not essential, but would have been climatic to show how the drill cuts
Thank you for the suggestion, it's much appreciated. Thanks again for watching.
You look like you're grinding a sort of four facet point but hand ground .
I was taught many years ago to use two 5/8 nuts tack welded together to check the point angle ( gives 120 deg ) near enough for most general usage .
The thanks should really go to your crew and yourself for taking the time to make these videos , i always learn something from them .
That works too. Thanks for the comment, I'm glad we're able to teach you something.
Nice Vid, if a person was going to buy a new stone and save it just for aggressive drill bit sharpening, what type and grit of stone would you recommend for larger HSS bits, say 3/4 to 1 1/2? On the smaller ones I have had real good luck touching them up with a disc sander if you stop before you butcher them too bad. Thanks again for the video.
You NEVER want a stone for "aggressive drill bit sharpening". The best stones and "grinders" for sharpening drill bits, chisels, etc are fine "finishing stones" and valve grinding machines. Would you sharpen a KNIFE BLADE you want to cut something as "soft" and easy to cut as MEAT with an "aggressive" stone? If not, why in the hell would you want a ragged, rough edge from an "aggressive" stone on an edge you expect/want/need to cut in between STEEL molecules?
Perfect thank you
Can you show how to grind an accurat spherical onthe end of a shaft. by using a surface grinder.
Very damn good for doing it by hand !
For smaller drills, I use a Drill Doctor. For larger drills, I do as you have shown. Thanks for sharing!
Wondering if Mr. Bailey has a video about reamers
will do soon
Would extra polishing/honing help?
good method, i use another but each to its own.
I use the surface grinder wheel for the finish hand sharpening, and my split point is near factory new.
Thank you for watching!
i would have liked to see you drill something with the resharpened drill.
We're on it, stay tuned.
The green thing on the desk looks a lot like bmw m3 mirror, but looks larger, what is it if you dont mind me asking?
Hi Don, I just installed new bearings in by cheep import milling machine spindle. I used a drift to remove the old ones. Put the new bearings in the freezer and heated up the housing and installed. installed the shaft using the same method with some grease. Can you show the correct method of installing bearings.I get a lot out of your videos as I expect others do and thank you for that. Cheers Dave.
You're already on the right track when it comes to installing the bearings! Interestingly enough, we're currently working on a video along these lines.
No chop saws in your shop? That is a great way to get that drill back to a good area for resharpen. I can never freehand a drill under a 1/16" and get the thing to drill straight.
Ha, no kidding. That's a very small drill to sharpen.
I used to routinely resharpen small drills down to .010" and .015". I had access to a very fine face wheel and folded a card over the shank to give me something to hold. the card had an angle cut in it for reference, but i had to keep a close eye on rotation and depth of grind. took a bit but i got very professional results after a while.
you make good videos
Came here because of my online class. Thank you sir for the idea😊
Welcome 😊
The higher the tip angle, the shorter the cutting edges. This results in less force required to turn the drill in the material. It also results in a stronger cutting edge. This is why a higher tip angle is used, among possibly some other reasons.
For smaller than 1/8" drills I don't even try to grind the relief with a radius. Just one single flat relief grind. I use an exaggerated relief angle just to make sure the heel doesn't rub. Too hard to see or measure an accurate 8-12*. I also just eyeball the lip length
I rest the front of the drill on my right index. Push, and then lower the rear in line to make my relief. Makes an almost factory looking grind. But, more than one way to skin a cat.
nice job like ur video's
Thank you
Other than broken fasteners, what is a use for left handed drill bits?
There are some screw machine applications that require left hand drills.
just a thought, the 135° would decrease the length of the cutting edge, meaning it would increase the pressure on the edge. the point is shaped like a cone(or pyramid, or triangle), if you reduce the height of the cone but leave the base the same diameter, the edges of the cone get shorter.
Sharpen a few and see if it's as easy as it looks, some people have it, some don't when it comes to sharpening drill bits. I had a guy that came buy the shop just to sharpen drill bits, they looked like brand new every time, left hand, Fortner bits and carbide, he polished the cutting edges like a mirror. He was good at it.
Exactly; some people have it, some people don't. Thanks for sharing, and thanks again for watching!
More often than not when I try sharpening a trashed drill bit the end of the bit doesn't look like it did from the factory when I'm done. It's difficult to get them indexed correctly when they break off or are worn badly.
Very true, sometimes it's rough to save them.
Try using a drill bit/chisel sharpening/angle gauge.
It's so easy to do it wrong. I always check it on piece of scrap. It takes a couple of extra minuets, but better than scraping something.
Thank you for watching.
Green wheel works well on HSS?
Yes it does.
Thank you
He's done that before at least once... lol great video.
I could use some help with finding tangent and degree of taper.
What are you referring to? OD grinding?
+SuburbanTool Inc yes
Just making sure. We've made a note of it, thanks for the good suggestion
Love it :D
how do you sharpen a countersink?
Part of our program at SCC was that we had to sharpen bits for grade and there was no "good enough".
2 nuts welded flat to flat give a simple workshop guide to test angle of cutting /lead edge and will show if one edge is proud etc ,,,simple and works well enough
Good tip, thanks for sharing!
all good
how to sharpen a gun drill, from stock to finished product?
Good video bud. Very important to mention, that it takes training to hand grind a drill, usually a few years as an apprentice. Also important is not to gauge the wheel, pass the drill across the width of the wheel for even wear. So, bud, your clearance was good but your point thinning needs more practice.......
If you can look at that bit and in particular the "trailing edge" of the flutes and think it's going to drill shit no matter how good his "point thinning" is you've never sharpened a drill bit in your life. The trailing edge has to continually "fall away" from the cutting edge as it follows the "twist" of the flutes. If it doesn't and remains "flat" or even worse has a big "dip" in the middle and then "climbs up" as it goes further "back" that bit won't cut a damned thing. As for passing the drill across the width of the wheel, if you "wear" a grinding wheel simply sharpening a drill bit, you have no clue what you're doing whatsoever and you probably "wear" a whetstone trying to "sharpen" a single iknife. His first "mistake" of many is using that stupidly coarse stone and it's all downhill from there. He apparently doesn't even know what a drill bit/chisel "gauge" is and there ain't no way to accurately "eyeball" the angle and length of the flutes to make sure the "point" is centered and that cutting edges "square" with each other and with the "axis" of the bit without one of those. There's a reason drill bits are PROPERLY sharpened to EXACTLY 118 or 159 degrees and "close enough" just don't cut it any more than having the flute lengths "close enough" and the "point" not centered on/in the bit is really "close enough". Drill bits and chisels are either sharpened PROPERLY or they're not sharpened at all.
Glad to hear you calling them drills and NOT bits. However, too much space between the rest and wheel and I can't believe you're using a rag to clean off the rest with the stone still turning.
I've been trying to track that down. What the hell is wrong with calling them bits?
Nothing in the world feels as good to me as removing metal with a machine, get the young ones early and they will be hooked for life.