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.

@LMerryman

3 жыл бұрын

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!

@900stx7

3 жыл бұрын

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.

That was a couple of great demonstrations Rob, thanks for sharing them.

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.

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.

Hi Rob. Very usefull information , thanks. Its great to hear your voice has recovered !!!

Cool demo, like the CBN wheel. Thanks for sharing.

A very useful video tutorial. Thanks!

Thank you for your generosity in sharing your knowledge. You represent the best of the tradition among woodworkers. -Jim

THANKS! tip re: resetting the bit between sharpening and splitting is something I need to try! - has never worked well up to now.

I have an entire tub of dull drill bits. Thanks showing how to bring some life into them

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!

@RobCosmanWoodworking

3 жыл бұрын

Glad it helped. We release 2 a week, if you subscribe and hit the notification bell it will alert you each time.

Thanks Rob great video again!

outstanding!

Rob, you are a wealth of woodworking information,thank you, Jake, excellent camera work.

@RobCosmanWoodworking

3 жыл бұрын

Thank you George!

Thanks, Rob - best tutorial I've seen on this.

@RobCosmanWoodworking

3 жыл бұрын

Nice of you to say, glad you enjoyed it.

Thanks for another, very useful, video.

Thanks for sharing that

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?

Rob is just wholesome as...

Thanks for this bit of information, you made a good point for saving money! 😉👍🏻👊🏻

@RobCosmanWoodworking

3 жыл бұрын

Glad you found it useful

Your beginner insights are so valuable.

Good to know thanks 🙏

Is there anything you can't sharpen? Your instruction is great and you have changed my sharpening skills and habits!

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.

The CBN wheels are excellent. Great company to work with. I have an older version of the drill dr & it works really good.

@RobCosmanWoodworking

3 жыл бұрын

I love mine

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 :)

Cool, thanks. I could apply this with the cheap corundum drill bit sharpener, I just bought.

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.

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).

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

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.

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. :-)

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.

@RobCosmanWoodworking

3 жыл бұрын

Good tip. Thanks

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.

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 !!!

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.

Useful video and well presented. Please don't breathe the carbide dust.

HI rob cool machine to sharpen drills.

@RobCosmanWoodworking

3 жыл бұрын

Drill Doctor. Get one

@MANJITSINGH-ko2oi

3 жыл бұрын

@@RobCosmanWoodworking Thank u I will.

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

This will save me money not buying new drill bits - maybe then I can afford the wheel 😋

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 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.

How did you know I have 453 dull drill bits in my shop ! This is a much appreciated video!

@RobCosmanWoodworking

3 жыл бұрын

I didn’t. I was tracking 418?

@danielgeng2306

3 жыл бұрын

RobCosman.com you’re the best my friend!

LOL! I just noticed you have a low roman bench on your exercise machine / storage rack! (11:36)

@RobCosmanWoodworking

3 жыл бұрын

Of course. Cant you tell how buffed I am?

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 ...

@RobCosmanWoodworking

3 жыл бұрын

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!

Would of liked to seen them used on steel after sharpening

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.

@RobCosmanWoodworking

3 жыл бұрын

Get a used one. They are readily avaliable

I always put a back angle on the back side of the flute and it makes the point more of a cutting tip.

@RobCosmanWoodworking

3 жыл бұрын

Thats the way to do it

Sharpened me hole saw with a file the other day. Can't believe people never do it.

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.

@RobCosmanWoodworking

3 жыл бұрын

I think mine is 10x

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?

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.

@RobCosmanWoodworking

3 жыл бұрын

Thanks Terry, I didn’t know that! New shop rule.

Can you use the Drill Dr to refashion a broken bit? Logic indicates that you should be able to.

@carlbruschnigjr1757

3 жыл бұрын

You're better off roughing in the shape with a grinder, then using the Drill Dr.

what about sharpening the side edges along the shaft? don't those also wear?

@RobCosmanWoodworking

2 жыл бұрын

Never touch them, they determine the Inside Diameter of your hole.

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.

@RobCosmanWoodworking

3 жыл бұрын

Sounds interesting. I will give it a try

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.

@shannoncarrier7122

8 ай бұрын

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.

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

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.

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.

@RobCosmanWoodworking

3 жыл бұрын

all good stuff, thank you.

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.

Hold ur hat when u check the price. Poor me can buy a few drill bit "SETS" from old Harbor Freight....Maybe 1 day... we will try it with a wheel I got off Ebay that has some diamond chips{so it says} in it. Thanks for the vid.! Rock on!

@RobCosmanWoodworking

3 жыл бұрын

I recommend getting higher quality drill bits that last way longer, sharpen better and in the long run save you money

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.

@RobCosmanWoodworking

3 жыл бұрын

If you are drilling in wood my experience is the angle is not critical, the relief angle and symetrical nice grinding is

@John-gm8ty

3 жыл бұрын

@@RobCosmanWoodworking wood is much easier for sure.

@John-gm8ty

3 жыл бұрын

@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.

Rob drill doctor nooooooo

Sharpen your own bits and save money . Buy a drill doctor....or buy enough bits to last you a life time

Hi Rob, my neighbor (an old cabinet-maker) has used the Kaindl SM 180 to sharpen his tools for 10 years: kzread.info/dash/bejne/onp_qdCKiNObkrQ.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.

sorry but drill bits are literally cheaper than my time

@RobCosmanWoodworking

3 жыл бұрын

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.