My shop instructor taught us that the fastest way to damage any cutting tool was to stress it thermally. I'm surprised that a fluid wasn't used to help transfer heat away from the cutting edges.

Thank you. As a woodworker I am not up on all of the ins and outs of steel. Clear and simple explanation of why and how to do this. Much appreciated.

The little diamond wheels for your Dremel from harbor freight are quite useful for small jobs

There are small diameter CBN & PCD, (diamond), drum bits available which work well for both creating/modifying carbide cutting tips which don't cost a fortune & work nicely for making positive rake cutting edges. One of my fav go to's for rough cutting steel, (when the piece won't fit in my saw(s)/shop is an ancient Skil 77 worm drive w/ a diamond masonry blade too worn to cleanly cut tile in my wet saw. Been using them both w/ a an air nozzle for clearing slag & cooling for 15+ years; neither the 50 yr old saw or the 'dead' blade know the word quit. A note of caution when grinding carbide, (or cobalt drills). Carbide contains cobalt. Cobalt is NOT healthy for your lungs OR body. I'm struggling w/ how to make a new diamond abrasive based grinder safe, right now. I try to batch my carbide grinding to lessen the prep & clean up work. I vacuum the grinder/saw & area before, during & after the work and wear a cartridge type respirator in the during & after phase, then go outside & blow off my body. You don't want an accumulation of the stuff in your shop. Cobalt is mildly radioactive, but has enough 'buzz' to mess up your life, down the road. Good vid, I've found masonry bits to come in handy, at times. I just saw some carbide tipped HSS bits on Ali Express for a good price. Don't bad mouth Chinese stuff until you try it; there is some excellant quality tooling out there, at a fraction of US price. (CNC has been the great equalizer & put a turbo'd the improvement in Chinese products, compared to Japan's 20-30 improvement path, post WWII.

Great vid . As a Greenhorn in a machine shop as a lad . Boss gives me a hyd ram piston says cut in half . Friction saw and here you go . Did,nt tell me it was new and was playing trick .Thinking id be there for hours with a Hacksaw. Greeting from Australia

If anyone want's to try this, it's much cheaper to get a diamond circular saw blade. It will be a bit coarse but will work to grind carbide into shape. I've been using masonry drills to drill through broken taps and hardened carbon steel since the late 1970's, well before solid carbide drill bits were easily available (or affordable)

This was interesting. I'm 35 years as a glazier, and when the tile guys on jobsites started using the newer hard ceramic tile, we had a tough time getting through it with basic masonry bits. And we all broke tiles soon as we turned on the hammer function of our drills. So,we had to start using the carbide tipped spearpoint bits. These were and still are expensive, so I started using my little tabletop Harbor Freight tile saw which has a built in water tray to sharpen my bits. Naturally, other glaziers asked me to sharpen theirs, too. The smart ones, that is, who didn't want to spend ridiculous money on new ones for every job. Sure, I could have built the price of the bits into the quote,but where's the fun in that? I learned to copy the angle of a new one, too,so they would function well. If you sharpen them at a 90 degree angle, they just heat up and bust loose from their braze.

That is really good to know. This was an awesome video.

Thank you for explaining this. Bed frame angle iron was eating all my drills.

Thanks for the easy to understand explanation. That makes perfect sense to me. 👍🏻👍🏻

Ray, once again a very informative post, thanks!

I used these masonry bits to drill holes into bearing races. Works like a charm.

Great video, very simple and easy to follow and i liked how your focus was on both cheap & easy to acquire drill bits as well as the tools needed to sharpen them. Almost every hobbyist has a either a bench grinder or disc grinder. Had never considered using the diamond tile discs for sharpening masonry bits to tackle drilling tool steel. If you broke a tap and needed it out, 3$ sounds like the bargain of the century for cutting it out.

Excellent info, thanks

Would a cutting fluid of some type have made a difference in the breakage ? I am assuming that the bits get hot and that’s contributing to breakage , but just curious if in fact the heat does play a part and if you have used cutting fluid in the past .

I bought a pack of 15 each 5/32" Diamond Hole Saw Drill Bits from Amazon for $7 and used just one to drill out a broken screw extractor.

Great video Ray

Impressed. Would be fun to drill some junk - discarded- no longer used safes. :)

Really good work man.

Excellent

I drilled holes in 24,000 low carbon steel rings for a Chainmail shirt that I wanted to rivet. I went through dozens of titanium, carbide, and steel 1/32” bits (cleared the hardware store out a few times 😂), but many just dulled, so I’ll try sharpening some as per this video to get more life out of them! :)

Great video, thanks for sharing

Thanks fo sharing

Very interesting. Nice work sir

Thanks mate!

Very interesting information, thank you.

I think a bearing right above the part would reduce the run out of the drill bit and possibly reduce carbide breakage.

Brilliant! 👍

very nice education my friend , thank you so much.

When drilling hardish material that isnt harder than your hss drills, i find that grinding a small flat at the edge (so its a neutral rake/cutting angle instead of positive) will let you drill a lot of materials that would otherwise just dull your drill in a few seconds, its slow though, chips dont curl up and evacuate as well as a normal grind.

I always save broken carbide stubs sharpen them like a flat screwdriver adding the relief like a regular drill but much flatter 150 deg and run relatively slow never over 800

nice bro

iused to do this in the late 70s but forgot about it, thanks

You can buy them. Called Artu titanium carbide tipped drill. Clean holes through hardened files.

Thank you.

Just sharpen a negative angle on the tip of your masonry bit. It takes less then minute. Try it. You find it works just as good if not better.

I have used carbide tipped glass and tile cutting drill bits for cutting hardened steel without reshaping the bit.

what is the technical name for those diamond dressing sticks? when i do a search for diamond dressing stick i get all kinds of results. what is the material in the stick called? Thanks! I'll be dressing a Norton surface grinding type diamond wheel

Note to self, buy carbide drill bits in the first place to drill through steel and consider jobber sets of common sizes. Got it.

Some useful video ideas are how to dial in a micrometer or how to grind drills I graduated the course and struggled with these 2 topics. Great video tho!!!

When I use a masonry bit and sharpen it I also do the leading edge that is the top part, as Those bits are never accurate in my estimation, and they never give me a true clean cut. I sharpen them as I sharpen a standard HSS bit.

Hard or hardened, if I may. I've recently seen "multi-material" bits at home despot that are outwardly the same as the masonry bits, but they have cutting geometry ground into the carbide, where the masonry ones seem to be ground without it.

Great video. Thanks. There is another method of drilling hardened steel that I used when I was a teenager working in a Chainsaw Shop. We sold milling attachments for chainsaws and had to drill holes in the chainsaws bar to mount them. The tip of the bar was hardened in those days before sprocket tips. It was impossible to drill through them with a drill press. It just burned up the drills. So we used HSS drill bits in a hand cranked drill press that applied pressure via a large hand nut. Cranking very slowly while applying pressure, we could easily drill the hardened steel. It took a bit of time, but not as much as you might think. Regards.

I'm curious about the runout in the diamond grinding wheel on startup. Seems to present itself again during the dressing operation and also in the 8x footage you see it a bit as the drills is sharpened.

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Hey this video is cool. Would you have any tips or ideas on best ways to drill out or remove. A broken piece of Easy out bolt extractor tool if possible Thanks 🙏

I have 2 stainless steel 1/4" bolts broke in a lower unit on a boat. Drilled through both bolts with a cobalt bit but then I broke a ease out in one of the bolts. So i got 2 more cobalt bits and 2 dremel cutters for hardened steel. Wish I'd known of this trick 1st. Now to destroy the bits and more than likely the dremel cutting tips.

Awesome pace and information density! I'm dealing with some kind of "undrillable" automotive unibody reinforcement sheet steel (around 14ga) which HSS does nothing. What's worse, they have to be hand drilled AND there are obstructions: will have to use either a compact right angle drill OR a 12" bit extension.

When you can figure out how the average machinist can enlarge the so called clearance holes in 123 blocks (other than edm) you’ll become a world wide hero.

I often need to drill a #6 machine screw body drill thru stainless, and HSS is not cutting the mustard. (pun intended. Sorry.) Do I just need better HSS, or maybe cobalt?

Hmm going faster, with cutting fluid and light pressure?

iF YOU would of used a vacuum cleaner nozzle chances are you would only need one drill. I have found that the chip load is what trashes the carbide tipped masonry bit. Also, different brand name bits have different grade carbide which one is better than the other. Just speaking from experience Sir.

I'll take that night and day. 🔥

Is it possible to just buy a cobalt drill bit for metal if I can't make it?

Carbide bit slowest speed you can constast pressure...had to do reapairs on machines many times

Do you have any indication of what type carbide is used for the bits?

I think you mean hardened steel. To drill harden steel as a compound verb you could work harden it with the drill bit cutting edge. To drill hardened steel you can use a stellite drill, if you know how to use it. Carbide tipped drills are not adequate.

Is the shank part of the end mill actually hardened though?

I use cheap diamond disks on a Dremel. Can cut all kinds of hardened steel with cheap masonry bits.

What about a diamond coated drill bit?

3 bucks and a lot of time! Thanks

Why did you decide to use dry drilling? Wouldn't flood-cooling have helped avoid the breakages?

What's your suggestion to drill out harden steel bolts stuck in the frame of my Jeep?

Wouldn't a cutting fluid be in order ?

Thirty year toolmaker, Carbide and turpentine for lubricant. Like butter

I use a diamond hand file I purchased from Amazon to hand sharpen the masonry bits to drill holes in hardened steel. Also use a guide to keep the bit centered when starting the hole as a prick punch obviously doesn’t do its job.

0:52 Stellite is not basically high speed steel. It doesn't even have iron/steel in it. Its tungsten carbide "glued" in a matrix with cobalt.

Can you please do a “how to use a pitch micrometer”?

I've done the same thing. You need to lower the speed.

What? No coolant?😂 informative video: the width of the “spade” of each bit was not compromised in your modifications?

hardened perhaps? unless harden is some steel type i've never heard of.

Even if the cutting edge lengths are off by even a slight amount the drill will wander then try and bring itself back to the centre resulting in triangular holes and a broken drill bit for the unwary. In my course I barely passed the lessons on twist drill sharpening by hand. Our lessons were as good as what the instructors were capable of. In fact, all of our basic lessons on milling machine cutting bit sharpening and twist drill sharpening should have been an entire stand alone course rather than 8 total hours of theory and practice, & let's move on. My other complaint is that there was not one word on line boring, nor rigging which is a required competency for being able to function in any job shop.

You should also use cutting oil .

HardenED steel

Porque al taladrar, usted no usa lubricante para enfriar la broca

I have drilled many holes into harden steal using cheap masonry drills. [0-1] Rockwell Range of C65. The end mill you drilled was "High Speed Steel End Mill Hardness" = Rockwell Range of C66~68. * I only used very short masonry drills. * I only slightly touched the "front face" at (90'), not removing any of the "brazing" holding the carbide insert. * I only slightly touched the "top face" to make a sharp cutting edge. [Not Sharp].. * You sharpened your masonry drill using (drilling non-harden tool steel) spade drill theory. Drilling Hardened Steel With Masonry Bits kzfaq.info/get/bejne/mr11gcJ-3c6roYU.html * Video: [2:17/9:57] Spade Drill used to drill "soft steel". How to drill harden steel kzfaq.info/get/bejne/ob5oh8hmyM6VimQ.html * Video: [8:35/9:59] Shows a shattered insert. * Video: [8:55/9:59] Shows drill chips coming out of the E/M center drilled hole. Drilling into a "partial hole" !!!. VERY Dangerous Procedure: * Video: [8:03/9:59] Shows using a "Very Long" masonry drill only having a 'soft cold roll steel drill shank'. * Under extreme drill pressure, what will happen if the E/M rotates in the very small "V-Jaws" in the vice ?

minor correction: it is "hardened steel" - you left the 'd' off which confuses my dyslexic and OCD brian 🙂

this is the reason why machining time increases heat due to shear and friction wears out the bit

How to drill HARDENED steel.

on hardened steel it's useless to grind a positive angle and it weaken the carbide tip. a neutral angle is more apropriate. as well as for cast iron, bronze and plastics. any materials in which you don't want to bite like a screw.

can i buy a diamond drill ?

Stellite, is Stellite, NOT HSS, NOT STEEL IN ANY WAY.

You weakened the tips on all the drills with the positive rake angle. Try next time with a slightly negative angle. Also, sharpen the end as you would a regular drill. Air blowing on it helps keep it cool.

The title is missing an ED (hardened)

I think you mean, "to drill harden-ED steel", right. Otherwise, the title has two different meanings.

HARDENED not harden

hardened^

Has anyone told you that you sound like ed kemper…..

Harden is a verb, not an adjective. You want "hardened".

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put some cutting oil on it

English… I thought you were friction drilling in some controlled manner…

Mate is there something wrong with your keyboard? It's hardened steel. And don't get me started on "I've sped up the video" ............

Some of the problems with broken drills may be caused by the width of the point between the cutting edges (the web). Carbide depends on heat from cutting speed to soften the steel. The point of the drill turns too slowly to generate the needed heat. It's almost like forcing a stationary drill through the material. I'd be interested to see if thinning the point would help. Also, on the interrupted cut where you went through the center hole you would need more speed. Interrupted cuts cause thermal fracturing in carbide.

It's "hardenED". And english is not even my native language.

Video started great, was right on point, and I was looking forward to enjoying the whole thing - but then you did what every other machinist does and assumed that we're all as smart as you are, or that we understand all the same verbiage. We aren't and we don't. Just over 2 minutes in you glossed over that little subject that obviously everyone knows about like it was nothing - angles of cutting bits/drill bits. You literally just said something like 'this one is positive and this is negative and neutral.....' and then you even rotated your wrist like that cracked the case. Huh? What part was the positive or negative part/ What angle? The side - bottom - top - like absolutely no explanation of what is meant by this. The tip of the bit? The flutes - like the inside or outside of them or both? Any explanation would be awesome because I have no idea what this means but everyone makes it sound important

Hardened steel not harden steel.

C'MON MAN first DRILL BIT made in USA 👍🏻 Cobalt bit is made where ???? ???????????????????????????????????????? this started WRONG

You don't use a cutting oil?

Small detail: there is no such thing as ḧarden" steel, there is, however, something called hardened steel- n'est-ce pas?