The flat spot between the flutes is called the web. HSS bits are sharpened at 118 degrees included angle. Carbide bits are sharpened at 135 degrees included angle. Carbide bits benefit more with a splint point than HSS. You don't really need a splint point for wood. The idea of the split point is to start a hole in METAL without using a center drill or a spot drill. It's basically a time saver for cutting metal.
As a note to the excellent contribution, 118 degrees included angle is a general grind reasonable for wood, plastic, and relatively soft metal like aluminum, brass, etc. The 135 degree is for harder metal material, and while you can drill the softer material with it, it will be more likely to splinter and snag on exit of the material. Thanks John for your contribution!
Long drills used for metal have extra thick webs for strength. I've sharpened drills where the web thickness is a third the diameter of the drill. This web has to be thinned after sharpening. Otherwise the tool pressure is too great an can cause the drill to shatter.
I haven't heard of a CBN wheel before now. It takes some practice to accurately sharpen drills by hand and the bigger the drill the more difficult it is. The first thing I made as an apprentice, 45 years ago was a drill angle gauge. I still have it. Love your work.
FINALLY! Someone that breaks it down to easy to follow instructions. I have butchered many bits. However, after this video I’ll give it another go. Thank You!
For those of use without bench grinders, a flap wheel on an angle grinder or a reasonably high grit on a belt sander also work for sharpening high speed steel bits. my hand held belt sander conveniently clamps into my bench vise using the handle, and I'm able to use it as an upright belt grinder, I also use it for some of my turning tools, I must admit that it is more difficult than using a bench grinder, but some times you just have to make do :)
As an old machinist I LOVE this video. I wish I could be there and we could sharpen bits all day!! I have a drill point gage I used to use. Kinda like a square but at 59 degrees. There's a scale on the 59 degree side to measure each cutting edge. Using this I could get the bit dead nuts accurate by hand. I wouldn't do the rotate thing. I would plunge straight in, rotate the bit 180 and plunge straight in the other cutting edge. When they are dead accurate I'd establish the relief. Also, you can relieve the center web by hand. It takes some practice but I prefer by hand to using a machine. Again, another great video. Now, where's my dull bits?
Thanks for the tutorial on sharpening drill bits. I don't do a lot of drilling so I don't have the muscle memory to hand sharpen my drill bits. I do have a Drill Dr and find it does a pretty good job. Thank you for sharing. Have a great day and please stay healthy.
been using a drill doc for over 10 years. for smaller bits it is super easy and repeatable. i love it and generally will use my bits for a month or so and then sharpen the whole kit. I use a sharpie to mark the ends and can tell which ones i have used.
Rob that is great tuition on sharpening bits. I understand mostly what you are saying about the back slope but do you have a picture of this section even a rough drawing. I was trying to sharpen bits and looking good but I could see something was not exact but didn't know what it was until I saw your video which gave me a good idea. Thanks a million you're a star and great instructor
Thanks for sharing this good technique for sharpening drills by hand. For best performance go one step further and check angles and lengths of both cutting edges with a drill Gage.
Great info. Suggestion: use a pencil or an awl with a very sharp point to indicate what part of the bit you're talking about. Your fingers would be good pointers on a 2" or 3" drill bit. :-)
Hi, is the material the same through the length of the bit? Or is there a limit to how much material you can remove before the bit is no longer usable?
My Dad taught me how to sharpen drill bits. Timber auger and spade and twist bits. Then he would get me to test each one in soft wood to ensure they were cutting right. He would watch me test them al and then tell me to do the ones again that didn't perform well enough. These were all brace and bit drill bits. This would happen every two weeks or so and with copious amounts of cups of tea doing it. Plus plane irons and chisels on occasions, but these he would do himself mostly. There were obviously more fun things I could have done but reflecting back there was nothing I enjoyed more than time spent with my Dad.
I worked as an inspector in a metal shop. I got the job of sharpening bits because nobody could do it better or faster. We had a jig but by hand was quicker knowing the angles. The angle for drilling soft metal is a little bit steeper.
I tried a drill doctor, ended up throwing it away! It was supposed to be the greatest thing ever! I did ok with larger bits near 1/2" but smaller bits would never line up properly despite following instructions. It ate a lot of metal off in a hurry. So I learned to free hand sharpen and got much better results. Usually use my hand cranked grinding wheel.
Just a word to the wise,, I've been in the machine shop for over 40 years and I've sharpened many drills actually it was one of the first skills I learned , I love your shop classes ! I watch all the time ! So I'm not being a smart a_ _ when I tell you this !! The drills are called TWIST drills and when you're grinding them you don't ROLL them you twist them !!! The drill doctor is soooo expensive ,, there are many other tools to use to sharpen twist drills believe me !!!
Thanks for posting this. You just demystified an entire school of thought (at least for me) keep it simple is best when baffled and self mastery comes from hands on learning with no apprehension. This actually really helps me......thanks again.
Being not very patient (for shipping) I went to Am@$on and looked for a CBN wheel - they have 80 grit wheels but they are made from aluminum. They are only a few dollars cheaper than yours and not sure what the quality is like. I like the idea of a machine that sharpens for me but I’ve already got a WorkSharp Ken Onion for knives/scissors and a WorkSharp for chisels; still had to get the Trends/Shapton for the planes but LOVE them! I think I’m going to get the CBN and learn the hard way ...
Can’t speak to the others on the market. We had ours custom made to our specs and since we use them on three grinders in the shop I can tell you they work as promised!
Thanks Rob. I delayed watching this for no reason... just went about my usual manual sharpening methods. But it only work some of the time. My sharpening grinder aged-out its belts and they are no longer available so I have to figure out what to do - or buy another grinder. For now, thanks for the concepts behind the bits.
I have a litle tip for you that kan do the sharpening a little easier specially for the beginners, instead of twisting the drill bit when you put it to the wheel try to just lift it strait up an dropp the back of the drill a little bit in the same mowement . When i first learned this about 30 years ago i said to the guy that he was crazy , then he said to me do me a favor and try it before you dismiss it . I did, and have used this metod ever since. In my work i mostly drill inn steel and aluminium, and with time you get a feel for angels and speed off the drill bit. I even use sanding belts for sharpening a drill bit and it works fine. Hope you will try this metod and experiment with it , and lett me know what you think.
Thanks Rob, great content as always, we'll share this out. Always a joy and plenty of great knowledge from you and your crew. Be safe, take care...(FB).
Free hand is a kind of ok if you just want your drill bit give you a hole. It is tricky to maintaining the center point dead accurate and balance on both size. Especially on small bits under 1/4 inch. Otherwise it will walk away from your punch mark. especially on a drill press, it will dance like a disco star and twist when you drill something hard. You need a jig of some kind to park your bit to the correct angle.or else you may need a couple hundred bucks to somebody else to make it for you, such as the drill doctor you have. that jig can be a good project for newbies?
If you sharpen a dull titanium or cobalt coated drill bit it’s ability to drill in hard metal is gone. They still will work for wood but for hard metals they’re disposable. Good technique Rob in restoring drill bits for your needs.
As this may be true for titanium because it's a coating that can be worn away, this is definitely not the case with cobalt as the materials used to make the bit are mixed as an alloy and not just baked on the surface.
Some analogies with plane blades and drill bits. 1. If you can see the edge then you have no edge. If you have to force the tool to cut through the material then check to see if it is sharp. 2. Heel clearance on the drill bit and plane blades. Allow 10 to 15 degrees. Wood compresses down while getting cut and pushes back up after the edge has passed. Typical machinist sharpened drill bits have only a few degrees of clearance since the metal doesn't compress. This is why you can a brand new drill bit (for metal), use it on wood and it requires more force to get it to cut. Also, less heel clearance on metal drilling bits means it has a thicker more durable edge. 3. When you get good at free hand sharpening drill bits it may take only 32 seconds. 4. Buy good quality drill bits so you don't have to sharpen as much. 5. The moment it gets dull then sharpen.
Hello Rob, good demo. I've been in tool and die and machining since the late 60"s and I want to caution you, do not grind carbide without a respirator, it is a carcinogen. And that's well documented so check it out if you would. Thanks again and Keep on smiling.
A drill bit angle guide is cheap and makes sharpening by hand much easier. Something like smile.amazon.com/Twist-Grinding-Diameter-Center-Sharping/dp/B0773GRK4T/ (I don't have that one, that's the first one I found. But it's pretty basic, and hard to screw up.) In a pinch, make one with a protractor and a piece of card stock. if you don't have the angles the same, the drill will not drill straight.
Color me surprised, I wouldn’t have thought you’d use a sharpening machine! I suppose if it’s easy, quick and effective, and it’s for a utilitarian purpose, then it’s fine.
I'd never use a machine (non of them are "good", and freehand is a bad idea, making a jig to keep your angle perfect is the best way to do it. this old tony has a long winded (old) video of how and why things are done, and it's well worth watching too.
@Mike Spencer yea that 40 years experience might have something to do with it :p also, having a shop and not taking on unskilled people who is goign to give them the skills? is that "someone else's job?" apprentices start someone, schools don't teach any of this stuff any more. and yes, some people so teach themselves, some bad, some not so bad, and with youtube and online courses, it's easier than ever.
The instructions that come with the drill doctor really suck, must have been made in China. I have 2 the first I bought almost 30 years ago and love it. the 2nd the 750 was a fail going by the instructions and DVD, almost found its way to the dumpster until I saw someone do as you and put the tab 2 notches over.
I guess you’re buying cheap drills? When I’m faced with the option of either sharpening my $18 3/32” Carbide drill or replacing it, I opt for the 45 second sharpening.
Hi Rob, my neighbor (an old cabinet-maker) has used the Kaindl SM 180 to sharpen his tools for 10 years: th-cam.com/video/pFKGnQXp5bQ/w-d-xo.html I bought it a few weeks ago and I am quite happy with it. It doesn’t replace the stones but saves a lot of work restoring old blades or sharpen drill bits. Silent, without overheating the tool, flat and you can watch what you are removing.
The flat spot between the flutes is called the web. HSS bits are sharpened at 118 degrees included angle. Carbide bits are sharpened at 135 degrees included angle. Carbide bits benefit more with a splint point than HSS. You don't really need a splint point for wood. The idea of the split point is to start a hole in METAL without using a center drill or a spot drill. It's basically a time saver for cutting metal.
As a note to the excellent contribution, 118 degrees included angle is a general grind reasonable for wood, plastic, and relatively soft metal like aluminum, brass, etc. The 135 degree is for harder metal material, and while you can drill the softer material with it, it will be more likely to splinter and snag on exit of the material. Thanks John for your contribution!
Long drills used for metal have extra thick webs for strength. I've sharpened drills where the web thickness is a third the diameter of the drill.
This web has to be thinned after sharpening. Otherwise the tool pressure is too great an can cause the drill to shatter.
THANKS! tip re: resetting the bit between sharpening and splitting is something I need to try! - has never worked well up to now.
I haven't heard of a CBN wheel before now. It takes some practice to accurately sharpen drills by hand and the bigger the drill the more difficult it is. The first thing I made as an apprentice, 45 years ago was a drill angle gauge. I still have it. Love your work.
FINALLY! Someone that breaks it down to easy to follow instructions. I have butchered many bits. However, after this video I’ll give it another go. Thank You!
Glad it helped. We release 2 a week, if you subscribe and hit the notification bell it will alert you each time.
Thank you for your generosity in sharing your knowledge. You represent the best of the tradition among woodworkers. -Jim
That was a couple of great demonstrations Rob, thanks for sharing them.
For those of use without bench grinders, a flap wheel on an angle grinder or a reasonably high grit on a belt sander also work for sharpening high speed steel bits.
my hand held belt sander conveniently clamps into my bench vise using the handle, and I'm able to use it as an upright belt grinder, I also use it for some of my turning tools, I must admit that it is more difficult than using a bench grinder, but some times you just have to make do :)
As an old machinist I LOVE this video. I wish I could be there and we could sharpen bits all day!! I have a drill point gage I used to use. Kinda like a square but at 59 degrees. There's a scale on the 59 degree side to measure each cutting edge. Using this I could get the bit dead nuts accurate by hand. I wouldn't do the rotate thing. I would plunge straight in, rotate the bit 180 and plunge straight in the other cutting edge. When they are dead accurate I'd establish the relief. Also, you can relieve the center web by hand. It takes some practice but I prefer by hand to using a machine. Again, another great video. Now, where's my dull bits?
Thanks for the tutorial on sharpening drill bits. I don't do a lot of drilling so I don't have the muscle memory to hand sharpen my drill bits. I do have a Drill Dr and find it does a pretty good job. Thank you for sharing. Have a great day and please stay healthy.
been using a drill doc for over 10 years. for smaller bits it is super easy and repeatable. i love it and generally will use my bits for a month or so and then sharpen the whole kit. I use a sharpie to mark the ends and can tell which ones i have used.
Good tip. Thanks
I have an entire tub of dull drill bits. Thanks showing how to bring some life into them
Rob that is great tuition on sharpening bits. I understand mostly what you are saying about the back slope but do you have a picture of this section even a rough drawing. I was trying to sharpen bits and looking good but I could see something was not exact but didn't know what it was until I saw your video which gave me a good idea. Thanks a million you're a star and great instructor
Is there anything you can't sharpen? Your instruction is great and you have changed my sharpening skills and habits!
Thanks for sharing this good technique for sharpening drills by hand. For best performance go one step further and check angles and lengths of both cutting edges with a drill Gage.
Rob, you are a wealth of woodworking information,thank you, Jake, excellent camera work.
Thank you George!
Great info. Suggestion: use a pencil or an awl with a very sharp point to indicate what part of the bit you're talking about. Your fingers would be good pointers on a 2" or 3" drill bit.
:-)
Hi, is the material the same through the length of the bit? Or is there a limit to how much material you can remove before the bit is no longer usable?
Cool demo, like the CBN wheel. Thanks for sharing.
My Dad taught me how to sharpen drill bits. Timber auger and spade and twist bits. Then he would get me to test each one in soft wood to ensure they were cutting right. He would watch me test them al and then tell me to do the ones again that didn't perform well enough. These were all brace and bit drill bits. This would happen every two weeks or so and with copious amounts of cups of tea doing it. Plus plane irons and chisels on occasions, but these he would do himself mostly. There were obviously more fun things I could have done but reflecting back there was nothing I enjoyed more than time spent with my Dad.
Thanks for another, very useful, video.
Hi Rob. Very usefull information , thanks. Its great to hear your voice has recovered !!!
The CBN wheels are excellent. Great company to work with. I have an older version of the drill dr & it works really good.
I love mine
A very useful video tutorial. Thanks!
Cool, thanks. I could apply this with the cheap corundum drill bit sharpener, I just bought.
I worked as an inspector in a metal shop. I got the job of sharpening bits because nobody could do it better or faster. We had a jig but by hand was quicker knowing the angles. The angle for drilling soft metal is a little bit steeper.
Rob is just wholesome as...
I tried a drill doctor, ended up throwing it away! It was supposed to be the greatest thing ever! I did ok with larger bits near 1/2" but smaller bits would never line up properly despite following instructions. It ate a lot of metal off in a hurry. So I learned to free hand sharpen and got much better results. Usually use my hand cranked grinding wheel.
Just a word to the wise,, I've been in the machine shop for over 40 years and I've sharpened many drills actually it was one of the first skills I learned , I love your shop classes ! I watch all the time ! So I'm not being a smart a_ _ when I tell you this !! The drills are called TWIST drills and when you're grinding them you don't ROLL them you twist them !!! The drill doctor is soooo expensive ,, there are many other tools to use to sharpen twist drills believe me !!!
Thanks for posting this. You just demystified an entire school of thought (at least for me) keep it simple is best when baffled
and self mastery comes from hands on learning with no apprehension. This actually really helps me......thanks again.
Thanks for this bit of information, you made a good point for saving money! 😉👍🏻👊🏻
Glad you found it useful
Good to know thanks 🙏
Being not very patient (for shipping) I went to Am@$on and looked for a CBN wheel - they have 80 grit wheels but they are made from aluminum. They are only a few dollars cheaper than yours and not sure what the quality is like. I like the idea of a machine that sharpens for me but I’ve already got a WorkSharp Ken Onion for knives/scissors and a WorkSharp for chisels; still had to get the Trends/Shapton for the planes but LOVE them! I think I’m going to get the CBN and learn the hard way ...
Can’t speak to the others on the market. We had ours custom made to our specs and since we use them on three grinders in the shop I can tell you they work as promised!
Thanks Rob great video again!
Useful video and well presented. Please don't breathe the carbide dust.
Reducing the chisel point or web was a smart idea. I suppose you could do that with a small round diamond file if you didn't have that magic machine.
Thanks Rob. I delayed watching this for no reason... just went about my usual manual sharpening methods. But it only work some of the time. My sharpening grinder aged-out its belts and they are no longer available so I have to figure out what to do - or buy another grinder. For now, thanks for the concepts behind the bits.
Get a used one. They are readily avaliable
outstanding!
Your beginner insights are so valuable.
I have a litle tip for you that kan do the sharpening a little easier specially for the beginners, instead of twisting the drill bit when you put it to the wheel try to just lift it strait up
an dropp the back of the drill a little bit in the same mowement . When i first learned this about 30 years ago i said to the guy that he was crazy , then he said to me do me a favor and try it before you dismiss it . I did, and have used this metod ever since. In my work i mostly drill inn steel and aluminium, and with time you get a feel for angels and speed off the drill bit. I even use sanding belts for sharpening a drill bit and it works fine. Hope you will try this metod and experiment with it , and lett me know what you think.
Sounds interesting. I will give it a try
Thanks Rob, great content as always, we'll share this out. Always a joy and plenty of great knowledge from you and your crew. Be safe, take care...(FB).
I have the cheaper model (blue plastic) of the Drill Doctor that I bought many years ago. Works great, although it doesn't do brad bits.
I find that a flat edge works just as good as a round one save,s a bit of time as well as effort skill
Free hand is a kind of ok if you just want your drill bit give you a hole. It is tricky to maintaining the center point dead accurate and balance on both size. Especially on small bits under 1/4 inch. Otherwise it will walk away from your punch mark. especially on a drill press, it will dance like a disco star and twist when you drill something hard. You need a jig of some kind to park your bit to the correct angle.or else you may need a couple hundred bucks to somebody else to make it for you, such as the drill doctor you have. that jig can be a good project for newbies?
I always put a back angle on the back side of the flute and it makes the point more of a cutting tip.
Thats the way to do it
Thanks for sharing that
If you sharpen a dull titanium or cobalt coated drill bit it’s ability to drill in hard metal is gone. They still will work for wood but for hard metals they’re disposable. Good technique Rob in restoring drill bits for your needs.
As this may be true for titanium because it's a coating that can be worn away, this is definitely not the case with cobalt as the materials used to make the bit are mixed as an alloy and not just baked on the surface.
Some analogies with plane blades and drill bits. 1. If you can see the edge then you have no edge. If you have to force the tool to cut through the material then check to see if it is sharp. 2. Heel clearance on the drill bit and plane blades. Allow 10 to 15 degrees. Wood compresses down while getting cut and pushes back up after the edge has passed. Typical machinist sharpened drill bits have only a few degrees of clearance since the metal doesn't compress. This is why you can a brand new drill bit (for metal), use it on wood and it requires more force to get it to cut. Also, less heel clearance on metal drilling bits means it has a thicker more durable edge. 3. When you get good at free hand sharpening drill bits it may take only 32 seconds. 4. Buy good quality drill bits so you don't have to sharpen as much. 5. The moment it gets dull then sharpen.
all good stuff, thank you.
This will save me money not buying new drill bits - maybe then I can afford the wheel 😋
LOL! I just noticed you have a low roman bench on your exercise machine / storage rack! (11:36)
Of course. Cant you tell how buffed I am?
what about sharpening the side edges along the shaft? don't those also wear?
Never touch them, they determine the Inside Diameter of your hole.
What is the focal length of your magnifier? I seem to find only those that I have to nearly hit the object to see the magnified item.
I think mine is 10x
Hello Rob, good demo. I've been in tool and die and machining since the late 60"s and I want to caution you, do not grind carbide without a respirator, it is a carcinogen. And that's well documented so check it out if you would. Thanks again and Keep on smiling.
Thanks Terry, I didn’t know that! New shop rule.
How did you know I have 453 dull drill bits in my shop ! This is a much appreciated video!
I didn’t. I was tracking 418?
RobCosman.com you’re the best my friend!
Can you use the Drill Dr to refashion a broken bit? Logic indicates that you should be able to.
You're better off roughing in the shape with a grinder, then using the Drill Dr.
Would of liked to seen them used on steel after sharpening
HI rob cool machine to sharpen drills.
Drill Doctor. Get one
@@RobCosmanWoodworking Thank u I will.
A drill bit angle guide is cheap and makes sharpening by hand much easier. Something like smile.amazon.com/Twist-Grinding-Diameter-Center-Sharping/dp/B0773GRK4T/ (I don't have that one, that's the first one I found. But it's pretty basic, and hard to screw up.) In a pinch, make one with a protractor and a piece of card stock. if you don't have the angles the same, the drill will not drill straight.
Sharpened me hole saw with a file the other day. Can't believe people never do it.
Color me surprised, I wouldn’t have thought you’d use a sharpening machine! I suppose if it’s easy, quick and effective, and it’s for a utilitarian purpose, then it’s fine.
I sharpen my drill bits since as long as I remember having my drill. I don't "roll" I do lift to get re leaf
Iseen a SF patch on your wall. Were you 18 once ?
I'd never use a machine (non of them are "good", and freehand is a bad idea, making a jig to keep your angle perfect is the best way to do it.
this old tony has a long winded (old) video of how and why things are done, and it's well worth watching too.
If you are drilling in wood my experience is the angle is not critical, the relief angle and symetrical nice grinding is
@@RobCosmanWoodworking wood is much easier for sure.
@Mike Spencer yea that 40 years experience might have something to do with it :p
also, having a shop and not taking on unskilled people who is goign to give them the skills? is that "someone else's job?"
apprentices start someone, schools don't teach any of this stuff any more.
and yes, some people so teach themselves, some bad, some not so bad, and with youtube and online courses, it's easier than ever.
The instructions that come with the drill doctor really suck, must have been made in China. I have 2 the first I bought almost 30 years ago and love it. the 2nd the 750 was a fail going by the instructions and DVD, almost found its way to the dumpster until I saw someone do as you and put the tab 2 notches over.
Sharpen your own bits and save money .
Buy a drill doctor....or buy enough bits to last you a life time
Rob drill doctor nooooooo
sorry but drill bits are literally cheaper than my time
I guess you’re buying cheap drills? When I’m faced with the option of either sharpening my $18 3/32” Carbide drill or replacing it, I opt for the 45 second sharpening.
Hi Rob, my neighbor (an old cabinet-maker) has used the Kaindl SM 180 to sharpen his tools for 10 years: th-cam.com/video/pFKGnQXp5bQ/w-d-xo.html
I bought it a few weeks ago and I am quite happy with it. It doesn’t replace the stones but saves a lot of work restoring old blades or sharpen drill bits.
Silent, without overheating the tool, flat and you can watch what you are removing.