How to drill harden steel

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  • Опубликовано: 11 июн 2024
  • How to drill harden steel
    Drilling Through Hardened Steel
    In this video I will show you how to sharpen a masonry - concrete - hammer drill bits to cut harden steel
    I will demonstrate drilling into hardened steel with a cheap carbide drill bit
    this works well for drilling into knives or knife making
    it is preferred to use a mill or at least a drill press but it can be done with a hand drill but I do not recommend it
    In this video I share a quick tip on using a Masonry Drill bit to drill through a hardened Steel
    easy and cheap way to drill holes into hardened steel

Комментарии • 258

  • @psdaengr911
    @psdaengr911 17 дней назад +24

    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.

    • @cdrive5757
      @cdrive5757 10 дней назад

      I'm surprised he hasn't responded to this.
      Wakodahatchee Chris

    • @shopandmath
      @shopandmath  10 дней назад +5

      Your shopping instructor is correct
      Coolant or lubrication should’ve been used

  • @talltom1129
    @talltom1129 17 дней назад +10

    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.

    • @whirlwind8825
      @whirlwind8825 15 дней назад

      Porcelain tile ...use diamond bits

    • @talltom1129
      @talltom1129 12 дней назад

      @@whirlwind8825 me and whose money? They're cost prohibitive.

    • @shopandmath
      @shopandmath  10 дней назад

      Very innovative thinking

  • @saidutube
    @saidutube День назад +1

    Concise and thorough! Thank you and greetings from Patagonia Chile!!

    • @shopandmath
      @shopandmath  День назад

      from chilli that’s awesome
      Thank you for letting me know where you’re from. I appreciate that it. It’s kind of cool and thank you for taking the time to comment with a nice comment. It is so much appreciated.
      Thank you
      Ray

  • @georgedennison3338
    @georgedennison3338 Месяц назад +12

    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.

  • @2000sborton
    @2000sborton 17 дней назад +5

    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.

    • @shopandmath
      @shopandmath  15 дней назад +1

      Thank you Steve for your nice comment and thank you for taking the time to comment. It is much appreciated.

  • @michaelallen1432
    @michaelallen1432 15 дней назад +8

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

    • @shopandmath
      @shopandmath  10 дней назад

      I have not tried that, but it is a good suggestion for the next video. Thank you for sharing. Much appreciated.
      Ray

  • @zjtr10
    @zjtr10 Год назад +6

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

    • @shopandmath
      @shopandmath  Год назад +1

      thank you for your nice comment and thank you for taking the time to comment. It’s much appreciated.
      Ray.

  • @matthubbard8541
    @matthubbard8541 Год назад +2

    Ray, once again a very informative post, thanks!

  • @1crazypj
    @1crazypj Год назад +9

    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)

    • @bernardkinsky1637
      @bernardkinsky1637 Год назад +1

      I do the same, even made a blade sharpener out of a old tile cutter as the speed is only 180 rpm

    • @bernardkinsky1637
      @bernardkinsky1637 Год назад +2

      Same, worked for Caterpillar my job was removing broke taps bolts and studs.

    • @1crazypj
      @1crazypj Год назад +1

      @@bernardkinsky1637 Neat, probably works much better than mounting a circular saw upside down and spinning at high rpm

  • @Guds777
    @Guds777 13 дней назад +1

    Ahhhh, hahahahaha. I did read it as, how to drill harden steel, as in how to harden steel by drilling in it. Done that been there. Drilling 30mm hole in Hardox and even the carbide didn't work on it, fun times... :D :D

  • @beetroot7486
    @beetroot7486 Год назад +6

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

  • @Stan_in_Shelton_WA
    @Stan_in_Shelton_WA 12 дней назад +2

    I had never though of using a drill to harden steel, interesting concept.

    • @cdrive5757
      @cdrive5757 10 дней назад

      What? Did you actually watch the video?
      Wakodahatchee Chris

    • @Stan_in_Shelton_WA
      @Stan_in_Shelton_WA 10 дней назад

      @@cdrive5757 I already know how to drill hardened steel and don't need to drill harden steel.

    • @cdrive5757
      @cdrive5757 9 дней назад

      @@Stan_in_Shelton_WA Considering RUclips's reputation for ??? Titles, spelling, grammar, etc, your point seems trivial.

    • @Stan_in_Shelton_WA
      @Stan_in_Shelton_WA 9 дней назад

      @@cdrive5757 You sound like a very sensitive person.

    • @cdrive5757
      @cdrive5757 8 дней назад

      @@Stan_in_Shelton_WA I'm glad you feel that way. My parole officer thinks I'm combative!

  • @mindthependulum6245
    @mindthependulum6245 16 дней назад +1

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

  • @TradeWorks_Construction
    @TradeWorks_Construction Год назад +6

    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.

    • @shopandmath
      @shopandmath  Год назад +1

      Thank you for the nice comment and thank you for taking the time to comment. It’s much appreciated.
      Ray

    • @georgedunkelberg5004
      @georgedunkelberg5004 3 месяца назад +1

      Retired GM shoprat. Worked near a ring gear tapping machine. Broken, in hole taps were "set aside", and later "arced?" zapped? and ??? re-tapped. This was in the Lansing, Michigan "Forge-Plant" #2 rear axle assembly of 1969+ era. This process was utilized on Saturdays=overtime. As it was 'Splained to me..... "too much time and machining was invested to NOT attempt a repair.

  • @michaelallen1432
    @michaelallen1432 15 дней назад +2

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

    • @shopandmath
      @shopandmath  10 дней назад

      Thank you, Michael for the next comment and thank you for taking the time to comment. It is much appreciated.

  • @miles11we
    @miles11we 17 дней назад +2

    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.

    • @miles11we
      @miles11we 17 дней назад

      Obv isn't gonna go through actually hard stuff but its come in handy with materials that just wouldn't drill well but were softer than the hss

    • @alecgarner
      @alecgarner 15 дней назад

      I do this to drill through saw plate, it's a cheap and effective option.

  • @jeffreymason9841
    @jeffreymason9841 11 месяцев назад +9

    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 .

    • @shopandmath
      @shopandmath  11 месяцев назад +2

      Yes, cutting fluid would help all the demos that I’ve done in my three hardness , drilling videos were worst. Case scenarios just demonstrate the ability of hand, sharpening Concrete bits
      If you have the ability to use coolant and air at the same time, that would be probably the best situation for most steals if it is an extremely hard steel, and you can increase the rigidity and use oil, if the temperature is not excessive, that would also be a really good situation
      I hope this helps
      Ray

    • @georgedunkelberg5004
      @georgedunkelberg5004 3 месяца назад +2

      @@shopandmath Had a former Alanson, Michigan friend who made fixtures for testing wiring harnesses. Their materials were "plastic-non conductive". Elmer LaTocha taught me to "PECK DRILL"= CUT AND REMOVE BIT, SPINNINIG TO AIR COOLTHE BIT, THEN "PECK IT SLIGHTLY DEEPER, AND REPEAT. Cuss-ed as I am I needed to "see what NOT, following this method DID! THE HEAT OF FRICTION DRILLING YIELDS A LARGER HOLE IN THE "PLASTICS' " MATERIAL. We as a society "grow in knowledge by "Paying IT Forward".

  • @andyb7754
    @andyb7754 Год назад +2

    Very interesting information, thank you.

    • @shopandmath
      @shopandmath  Год назад

      Thank you for your nice comment and thank you for taking the time to comment. It’s much appreciated.
      Ray

  • @denisiwaszczuk1176
    @denisiwaszczuk1176 15 дней назад +1

    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

    • @shopandmath
      @shopandmath  10 дней назад

      Welcome from Australia
      I, too have had many other tricks played on me when I was new
      Thank you for sharing
      Ray

  • @mrkeopele
    @mrkeopele 10 месяцев назад +2

    very nice education my friend , thank you so much.

    • @shopandmath
      @shopandmath  10 месяцев назад

      I’m glad that you enjoyed the video
      And thank you for taking the time to comment. It is much appreciated.
      Ray

  • @pnfoster
    @pnfoster 13 дней назад +2

    Was hoping to learn how to drill hardened steel. Will keep looking.

    • @godfreypoon5148
      @godfreypoon5148 13 дней назад

      Same. This seems to be about how to harden steel with a drill. Never heard of drill-hardening before though.

  • @simon3065
    @simon3065 Год назад +2

    Great video, thanks for sharing

    • @shopandmath
      @shopandmath  Год назад

      Thank you for your nice comment and thank you for taking the time to comment. It’s much appreciated.
      Ray

  • @user-xp4ol3hl4q
    @user-xp4ol3hl4q День назад +1

    3 in one oil works great in s shop, and will preserve your tools against heat damage. Heat is especially a factor with brazed tool bits. Putting a nice sharp edge on any drill bit is easy if you have a diamond flat sharpener, in the same idea as a 3 by 8 inch stone.

    • @shopandmath
      @shopandmath  День назад

      if you don’t have a diamond wheel, some people have been commenting about using a small diamond wheel on a Dremel now I personally have never thought of that, and I will be incorporating that in on one of my next videos just to see how it turns out
      Thank you for commenting and thank you for taking the time to comment. It is much appreciated.

  • @chrononaunt
    @chrononaunt 19 дней назад +2

    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.

    • @shopandmath
      @shopandmath  17 дней назад

      thank you for sharing and I will have to try that tip. Next time I sharpen a bit.
      Ray

  • @brad2548
    @brad2548 14 дней назад +2

    Excellent

    • @shopandmath
      @shopandmath  9 дней назад +1

      Hi Brad, thank you for the nice comment and thank you for taking the time to comment. It is much appreciated.
      Ray

  • @chadherbert18
    @chadherbert18 27 дней назад

    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! :)

  • @markloubser2433
    @markloubser2433 15 дней назад +1

    Excellent info, thanks

    • @shopandmath
      @shopandmath  10 дней назад

      Thank you Mark for the nice comment and thank you for taking time to comment. It is much appreciated.
      Ray

  • @YoutubeTech82
    @YoutubeTech82 3 месяца назад +2

    Really good work man.

    • @shopandmath
      @shopandmath  3 месяца назад +1

      Thank you for commenting and thank you for taking the time to comment. It is much appreciated.
      Ray

  • @bensonideas295
    @bensonideas295 Год назад +1

    Thanks fo sharing

  • @williammorris1763
    @williammorris1763 15 дней назад +1

    I'll take that night and day. 🔥

  • @racedouge1
    @racedouge1 16 дней назад +2

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

    • @shopandmath
      @shopandmath  10 дней назад

      Have to try that thank you for sharing

  • @michaelwmauser1
    @michaelwmauser1 17 дней назад +1

    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.

    • @shopandmath
      @shopandmath  10 дней назад

      That certainly is a cost-effective way of doing it
      Switch off part about buying stuff from Amazon or the Temu as you never know what you get sometimes
      Thank you for sharing

  • @dizzolve
    @dizzolve Год назад +3

    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

  • @PatrickCoble
    @PatrickCoble 2 месяца назад +3

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

    • @shopandmath
      @shopandmath  2 месяца назад +1

      I’m glad that you like the video. Thank you for commenting and thank you for taking the time to comment. It is much appreciated.

    • @user-ox6nc6ly7f
      @user-ox6nc6ly7f 17 дней назад +2

      you are reving way too fast.
      use oil, if there is smoke slow down and add pressure.

    • @fatcatclark8428
      @fatcatclark8428 17 дней назад +1

      i love bed frames. I blow a hole in them with my cutting torch...

    • @pazsion
      @pazsion 13 дней назад

      iron and soft steel used in bed frames is very soft and shouldnt present any problem unless your using the wrong bit or running it backwards

    • @ralphwaters8905
      @ralphwaters8905 9 дней назад

      All the bed frames I've ever tried to drill are very high carbon and hard as hell. They can be cut easily with an abrasive saw BUT welds will be very brittle and crack easily. I no longer bother to scavenge them. CV axles are as tough as a boiled owl's beak too... 🦉🦉😤

  • @miguelcastaneda7257
    @miguelcastaneda7257 17 дней назад +1

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

  • @danl.4743
    @danl.4743 Год назад +1

    Brilliant! 👍

    • @raysfix
      @raysfix Год назад

      Thank you and thank you for taking the time to comment. It’s much appreciated.
      Ray

  • @mikesgabellone5089
    @mikesgabellone5089 Год назад +1

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

    • @shopandmath
      @shopandmath  Год назад +1

      You’re correct this trick is not new but it’s a good cost-effective way of producing holes and harder material
      Now, you can buy bits from Bosch and Dewalt without having to sharpen them

  • @stephenlett9208
    @stephenlett9208 6 месяцев назад +1

    Great video Ray

    • @shopandmath
      @shopandmath  6 месяцев назад

      Thank you for the nice comment and thank you for taking time to comment. It is much appreciated.

  • @pauloconnor7951
    @pauloconnor7951 Год назад +3

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

  • @LockBits-ts6eo
    @LockBits-ts6eo 3 месяца назад +1

    Thanks mate!

    • @shopandmath
      @shopandmath  3 месяца назад

      thank you for the nice comment and thank you for taking the time to comment. It was much appreciated.
      Ray

  • @benmcguire603
    @benmcguire603 Год назад +2

    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.

    • @shopandmath
      @shopandmath  Год назад +3

      It’s a visual illusion.
      It has to do with the bit rate of the video so when it speeds up and slows down it looks like it’s a wobbling

  • @deeperm8763
    @deeperm8763 5 месяцев назад +1

    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 🙏

    • @shopandmath
      @shopandmath  5 месяцев назад

      I would use the same technique that I used in one of my previous videos on how to remove remove a tap by using a guide plate
      ruclips.net/video/rSShHH2Us5Q/видео.htmlsi=l5ookITZoDb7UuJn
      Best of luck let me know how it goes
      Ray

  • @WL-mt4mv
    @WL-mt4mv 18 дней назад +2

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

    • @shopandmath
      @shopandmath  17 дней назад

      I have a couple glass bits in my toolbox from when I was a little kid and I used to cut glass back in the day before we had all the fancy windows we used to have paint glass windows with the holes drilled in with the plastic handles to slide the windows open and closed
      I was going to make a video on using those as well or using them as an option, but I just couldn’t bring myself to damage one of those tools because I’ve had them for so long
      Thank you for sharing and thank you for commenting and taking the time to comment. It is much appreciated.

    • @WL-mt4mv
      @WL-mt4mv 8 дней назад

      @@shopandmath You can get a set of 6 bits from Harbor Freight for less then $10.

  • @ArcticBlues1
    @ArcticBlues1 2 дня назад +1

    Thank you.

    • @shopandmath
      @shopandmath  День назад

      thank you for the nice comment and thank you for taking the time to comment. It is much appreciated.
      Ray

  • @philosophyofvalue8506
    @philosophyofvalue8506 14 дней назад +1

    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.

  • @ralphsawyer9535
    @ralphsawyer9535 6 дней назад +1

    Best way to hard tool a hole... carbide drill and constant compressed air blowing those hard chips out and cooling the hardened tool steel. Drill at a fairly fast rpm, depending on drill diameter, and peck... cut and get out, cut and get out, all while using your air hose or even a spray mist with the coolant shut off so its just blowing cool air. Carbide needs some rpm, especially smaller drill bits. You can use a good American made 10% cobalt bit if interupted cuts are involved, bc interupted cuts will destroy carbide. But you can't run the cobalt as fast as carbide. Flood cobalt bits with coolant.
    I'd say 800 rpm for a 1/4" carbide bit, 300 rpm for a good American made 10% cobalt 1/4" bit.
    Might want to ride your quill lock just a little when breaking thru so you dont knock the corners off your bits.

    • @shopandmath
      @shopandmath  6 дней назад +1

      That’s a good explanation. Thank you for sharing.
      Most cobalt drills at 5%. I haven’t heard of a 10% one. Do you know the manufacturers name?
      There are many types of cobalt drill bits, but the most common are M42 cobalt drill bits (composed of 8% cobalt) and M35 cobalt drill bits (5% cobalt)

    • @ralphsawyer9535
      @ralphsawyer9535 6 дней назад +1

      @@shopandmath You are so welcome and I hope you have good results.
      I've been retired for about 5 years so I cant recall the brands that make hss-cobalt 10% but I know they were American made. You got my curiosty up so I've kind of been looking around on the web with no luck, only 8% like you said. I will check my tooling later on to see if I have anything that will jog my memory. The 8% should work too with a little slower rpm and flood coolant. I could always tell a big difference between American hss-cobalt and imported, in all grades.
      I see MoMax makes a 10% but all I've found there are square bits, drill blanks, and part-off blades. Maybe try TRW Putnam or Cleveland Greenfield?

  • @RustyInventions-wz6ir
    @RustyInventions-wz6ir 18 дней назад +1

    Very interesting. Nice work sir

    • @shopandmath
      @shopandmath  17 дней назад

      thank you for the nice comment. It is very much appreciated and thank you for taking the time to comment.
      Ray

  • @sawaab.a3756
    @sawaab.a3756 Год назад +2

    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!!!

    • @shopandmath
      @shopandmath  Год назад +3

      I have videos on both of those topics.
      In the how to read a micrometer, it shows taking a micrometre apart and what you have to do to adjust it to dial it in or reset
      The drill making video is older one of the first videos that I created.
      Good hearing from you Sawaab
      Have you seen the new campus?

  • @burtreynolds3143
    @burtreynolds3143 11 дней назад

    Awesome !

  • @CMAenergy
    @CMAenergy 18 дней назад +1

    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.

    • @shopandmath
      @shopandmath  17 дней назад

      That is a very good suggestion. Thank you for commenting and thank you for taking the time to comment. It is much appreciated.

  • @borisj4054
    @borisj4054 18 дней назад +1

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

    • @shopandmath
      @shopandmath  17 дней назад

      you are correct they do work well I have the ones from Milwaukee and from Dewalt both of those brands in my personal opinion I would still want to add more relief to the back clearance angle
      Thank you for sharing and thank you for taking the time to comment. It is much appreciated.

  • @cellorange-yo8jw
    @cellorange-yo8jw Год назад +1

    nice bro

  • @TheOneAndOnlySame
    @TheOneAndOnlySame 15 дней назад

    Hmm going faster, with cutting fluid and light pressure?

  • @robertpeters9438
    @robertpeters9438 18 дней назад +1

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

    • @shopandmath
      @shopandmath  17 дней назад

      you are most likely correct
      The reason for me doing this is the type of videos that I shoot are one and done style
      ideally, I would’ve he treated my own piece of material brought it to the hardness tester, but I’ve had people tell me that I swapped the material out which obviously isn’t true but still it kind of puts the I’m being scammed in the air so I decided to choose something which everyone can identify with and see. I understand that that’s hard because it’s an endmill
      Thank you for contributing and thank you for taking the time to comment. It is much appreciated.

  • @chauvinemmons
    @chauvinemmons 19 дней назад +1

    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

    • @shopandmath
      @shopandmath  17 дней назад

      thank you for sharing
      And thank you for commenting, and taking the time to comment. It is much appreciated.
      The little things we save that most people would consider scrap can be quite valuable, especially if you resourceful

  • @jimsvideos7201
    @jimsvideos7201 15 дней назад +1

    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.

    • @shopandmath
      @shopandmath  9 дней назад

      Yes, a lot of the companies that make quality tools also make them as well. I have some from Dewalt and Milwaukee
      They have a neutral, rake angle

  • @mjwint
    @mjwint Год назад +2

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

    • @shopandmath
      @shopandmath  Год назад +1

      sorry, I don’t know what type of carbide or grade of carbide is in these drillbits
      I was just trying to demonstrate how for very little cost at home and you can drill through very hard steel.
      I would’ve brought the Anmol up to the hardness tester to find out the exact hardness one. Unfortunately, we just moved it and it’s still in lockdown mode or transportation mode.
      I pick those Drill bits up from the restore, which is the cheapest place. I could find they only cost me a dollar each no tax Canadian.
      If you watch the shop tour video you will see that I have access to millions of dollars worth of equipment and an excellent environment to machine almost anything
      my friends keep telling me that I need to make videos that the average person with the most basic tools can still drill out a broken tap or Harden Bolt at home. Sorry I couldn’t answer your question.
      Ray

  • @barrykilts4506
    @barrykilts4506 4 дня назад

    What about concrete bits?sorry I didn’t watch all the way thru first but what about using oil or any lube?

  • @andrerousseau5730
    @andrerousseau5730 Год назад +1

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

    • @shopandmath
      @shopandmath  Год назад +2

      Coolant or oil would have been preferred
      I was doing it on a drill press and didn’t want to make a mess
      My parameters for this video
      Number one
      accessibility for everybody with limited tools (someone with a drill press, or hand drill and a grinder could make these drillbits for around $10)
      Second
      Pick material that everybody understood was extremely hard. Unfortunately, our hardness tester was in shipping mode from the move still
      And I could not tell you the exact hardness of the material.
      So I picked something that is easily recognized by everyone and they understand that it’s extremely hard.
      Third
      Demonstrate an easy and basic set up
      I currently have three videos, including this one on drilling harden material.
      Do you have any ideas for my next video?
      Thank you for taking the time to comment. It’s much appreciated.
      Ray

  • @Richard_L_Y
    @Richard_L_Y Год назад +2

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

    • @shopandmath
      @shopandmath  Год назад +2

      Yes, this end mill is through hardened

  • @NoferTrunions
    @NoferTrunions Год назад +3

    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.

    • @raysfix
      @raysfix Год назад

      send metal has its own problems for drilling, especially where it wants to pull the drill in to the material after you break through the surface this causes the drill to slip inside of the chuck and damages shank
      there are some tricks to prevent this from happening, such as reducing clearance or drilling with a negative rake
      If the material is plated, or has a coding like titanium by trading, there are some bits available that will melt the metal, but I think that they’re only available with a Rigid set up and not compatible with hand drilling

  • @johnnyrotit844
    @johnnyrotit844 9 месяцев назад +2

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

    • @shopandmath
      @shopandmath  9 месяцев назад +2

      yes, it is possible to go to cobalt drill. They can be a little bit. Pricey, there are a few other brands that make carbide tip drills that drill freely. Milwaukee and Dewalt Bosch makes a set.

  • @KW-ei3pi
    @KW-ei3pi 18 дней назад +2

    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.

    • @user-ox6nc6ly7f
      @user-ox6nc6ly7f 17 дней назад +1

      a chainsaw bar is easy to drill with a quality HSS drill or cobalt drill. even a bi-metal hole saw. if not, you are reving way too fast. use oil, smoke means you are reving too fast.

    • @shopandmath
      @shopandmath  17 дней назад

      thank you for sharing. It is much appreciated.
      I do have on order a red hardness drillbit but apparently it takes six months for this thing to come from China and it’s like $200 for a 3/16 bit. It uses high temperature red heat to melt through the material which isn’t really drilling but when it comes in, I will make a video on that as well.

  • @russellfaison954
    @russellfaison954 12 дней назад

    What brand of magnifying visor is that? can you provide a link as well?

    • @shopandmath
      @shopandmath  8 дней назад +1

      Sorry Russle I picked those up at Amazon return place I like them but if I had to pay full price, I probably wouldn’t have gotten them

  • @martkbanjoboy8853
    @martkbanjoboy8853 15 дней назад +1

    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.

    • @shopandmath
      @shopandmath  10 дней назад

      Our year one apprentices have to sharpen a 60° threading tool
      And a drill
      You would be surprised that the number of apprentices that do not have to sharpen drills anymore. I would say around 80% don’t ever have to sharpen a drill. When the drills do they go get a new one or a sharpened one they have people in the tool room that sharpened and drills whatever cutting tools they use.

  • @NTSRFR4
    @NTSRFR4 11 дней назад +1

    How much did those drill bits cost and your time? Did you figure that in to the $3 cost? No cutting fluid? I don't quite understand how the dressing thing works. Does it just clean out the built up debris?

    • @shopandmath
      @shopandmath  11 дней назад

      it was a total of three dollars because I used three bits
      The idea or concept of this was to drill hardy material as cost-effectively as I possibly could using only machines that I have at home
      This concept might be a little hard to understand and it it would take a long paragraph to explain properly
      I have access to millions of dollars worth of machining equipment and my buddies keep telling me yeah you can do this but what happens when I’m at home and I break a bolt working under a car or something like that how do I get that out?
      There is bits available that you can buy made by manufactured by Dewalt and Milwaukee
      They are considerably more expensive
      I hope this answered your question
      Ray

  • @ralphwaters8905
    @ralphwaters8905 15 дней назад +1

    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?

    • @shopandmath
      @shopandmath  10 дней назад +1

      Stainless steel can be tricky. It depends on what grade it is and it also depends if it’s been work hardened.
      If it is being work hard, solid carbide has a very difficult time getting through it. If it’s not work hard, I would recommend a cobalt drill or maybe a split point Walter drill. Hopefully this helps.
      Ray

  • @37yearsofanythingisenough39
    @37yearsofanythingisenough39 Год назад +1

    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.

  • @stevenjordan6389
    @stevenjordan6389 10 дней назад +1

    No oil?

  • @rmerrick123
    @rmerrick123 Год назад +1

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

    • @shopandmath
      @shopandmath  Год назад

      For bolts, I would use a drill that has cobalt in it. Dewalt makes them and Milwaukee makes them unfortunately since it’s in the frame, you will have to use a hand drill
      If you have a good drill sharpening skills, you should be able to do it with one drill no problem if you have difficulty sharpening drills and don’t have access to someone who does I would suggest getting more than one
      I would also suggest drilling out the centre of the bolt, and using an easy out to remove the rest of the bolt
      If the bolt still has a head on it, there are multiple ways of removing that using extractors which do not require drilling.
      Wish you all the best let me know how it goes.
      To stop the drill from wondering if you can put a Centre punch Mark in the bolt .

    • @rmerrick123
      @rmerrick123 Год назад

      @shop and math , yeah...not only in the frame..but on the underside in the rear wheel well. In a very hard to reach spot of course. Thanks for the tips.

    • @shopandmath
      @shopandmath  Год назад

      @@rmerrick123
      A couple more ideas that you might want to consider
      I don’t know if it’s possible to get an easy out or stud remover into the position that you’re trying to get at
      I have used a Dremel type tool that has a 90° head to get into super tight spaces, then modified and easy out basically made it shorter to fit inside the tight space use an air chisel to place the easy out inside the hole
      And removed it with a ratchet wrench
      Best of luck let me know how it goes
      Ray

  • @a-fl-man640
    @a-fl-man640 15 дней назад +1

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

  • @gibbogle
    @gibbogle 15 дней назад +1

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

  • @oneyaker
    @oneyaker 14 дней назад +1

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

    • @shopandmath
      @shopandmath  9 дней назад

      A couple people have commented about the diamond discs for the Dremel. Honestly, I never even thought about that. I am going to have to give it a try. Thank you for sharing and thank you for taking the time to comment. It is much appreciated.

    • @oneyaker
      @oneyaker 9 дней назад

      @@shopandmath I use magnifying goggles to get a really close look. I either lock the drill or the dremel in a vice for more control and the diamond will shape the carbide very quickly. It is a good idea to clear any steel and brazing with a normal cutoff disk first because the diamond will not cut it well.

  • @philcamp8621
    @philcamp8621 3 месяца назад +1

    What about a diamond coated drill bit?

    • @shopandmath
      @shopandmath  3 месяца назад +2

      It depends
      They generally only do diamond coating real diamond coating on carbide. The diamond coating is a throwback from about 15 years ago. It’s a technology that they used on the space shuttle to deflect heat.
      On high-speed, steel or cobalt it wouldn’t do anything
      Think of coatings Like a chocolate covered cake those small Vashon cakes or Joe Louis the coating on the outside is hard very hard and the material behind. It is soft like a cake.
      The backing material must be very hard and tough to hold onto the coding on the outside to prevent it from flaking and cracking off
      I’m hoping that I explain this well articulated enough that you can understand what I’m trying to get at
      Ray

  • @Tome4kkkk
    @Tome4kkkk 12 дней назад

    What happens to cobalt drill bits after resharpening? Do they become "just as good like HSS, just yellow"?

    • @shopandmath
      @shopandmath  8 дней назад +1

      Cobalt is an alloy that’s added to steel about 5% that will make the drill cost probably three or four times more than high-speed alone
      When you re-sharpen the tool bit
      It should be very close to the original quality before you sharpened it. The only time that the tool might degrade a little bit is if you overheat it and you and aneal the hardness.

    • @Tome4kkkk
      @Tome4kkkk 7 дней назад

      @@shopandmath Thanks you very much. Up to this point I suspected it right be just a surface treatment. Do you still buy regular HSS drill bits? I'm thinking of buying the DeWalt 19pcs HSS set for $25+.

    • @shopandmath
      @shopandmath  7 дней назад +1

      I still buy standard high-speed tool bits. Most of the time I have people given to me for free, but having a good quality set is a must have.
      For the more difficult jobs, I have solid carbide and carbide tip drills

    • @Tome4kkkk
      @Tome4kkkk 7 дней назад +1

      @@shopandmath Agreed. I bought a set of hand-picked sizes solely for drilling for threading/tapping but one of the bigger ones saved my buttocks when dealing with a stainless steel piece. BTW, I work with very limited tool set and have no specific application for stainless steel so I'm happy to say I recently got rid of my last pieces of stainless steel scrap :D

  • @tinycuisine6544
    @tinycuisine6544 Год назад +1

    3 bucks and a lot of time! Thanks

  • @MAZEMIND
    @MAZEMIND Год назад +1

    Subscribed

  • @victoryfirst2878
    @victoryfirst2878 11 месяцев назад +3

    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.

    • @shopandmath
      @shopandmath  11 месяцев назад +2

      You’re right on all accounts the thing that would improve the cut ability or quality of cut would be rigidity
      This video in my other three videos on the same topic or design to show people that they can make these tool bits and cut harden material with very little cost involved and not that much experience
      If you watched any of my other videos especially the shop tour video, I have access to millions of dollars of equipment but all my friends that are not in the trade so I need to make videos for the people that don’t have all of the high-end equipment this was kind of my Answer to those types of scenarios
      Thank you very much for commenting and sharing. It is much appreciated.
      Ray

    • @victoryfirst2878
      @victoryfirst2878 11 месяцев назад +2

      @@shopandmath I will definitely check out the other videos. So nice to meet another machinist Ray like myself Vic. I can relate to your methodology and logic. I have helped so many people who also do not have access to high dollar machine shop. I have one for you Sir. You can take a HSS drill bit and harden it to drill right through just about anything by heat treating it in Mercury. The bitch is you will go through at least a dozen or more bits before one will survive the plunge and temperature shock. Thank you Ray you made my day fella. Good luck and peace to you Sir. Vic
      P S carbide cement drills bits these days are really the bottom of the barrel in quality. They use to be really good when they were made in the USA. Years ago Ray. Over and out.

    • @shopandmath
      @shopandmath  11 месяцев назад +2

      @@victoryfirst2878
      Hi Vic
      I’ve never done any heat treating with mercury we have a heat treating oven and it is only used in the tool and die apprenticeship and maybe a few other classes
      One of the videos I was contemplating making, was taking a piece of heat, treatable metal cutting it in half making a turning tool out of 1/2 and machining the other piece non-heat treated piece into a shape to demonstrate the physical change of hardness on the same piece of metal
      Again, thank you for commenting. It is much appreciated. Have a nice day.
      Ray

    • @victoryfirst2878
      @victoryfirst2878 11 месяцев назад

      @@shopandmath Good luck with your endeavors Sir.

  • @felicianozamora242
    @felicianozamora242 Год назад

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

    • @shopandmath
      @shopandmath  Год назад

      Yes, a pitch micrometre video is in the works but it’ll be a little while yet.
      Thank you for taking the time to comment. Much appreciate it.

  • @xONEWINGx
    @xONEWINGx Год назад +1

    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.

    • @raysfix
      @raysfix Год назад +1

      You are correct.
      I am guilty of dumbing down my comparison
      I was just trying to convey a comparison of metal that people would be able to understand
      Thank you for taking the time to watch the video and comment. It is much appreciated.
      Ray

  • @glasslinger
    @glasslinger 10 дней назад

    Will a drill doctor machine do this OK?

    • @shopandmath
      @shopandmath  8 дней назад

      I have a drill doctor. I’m not sure if the wheel inside will sharpen carbide.

  • @bigdave6447
    @bigdave6447 Месяц назад +1

    HardenED steel

  • @kidkv
    @kidkv 14 дней назад +1

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

    • @shopandmath
      @shopandmath  9 дней назад

      Thank you for your comment and thank you for taking the time to comment
      If you look through the comment section, you’d be surprised how many people say that you can’t do this or that this doesn’t work

  • @ronamato3245
    @ronamato3245 5 месяцев назад

    You should also use cutting oil .

  • @janvanruth3485
    @janvanruth3485 12 дней назад +1

    spa drills have a purpose.....

  • @apoloniorodriguez7251
    @apoloniorodriguez7251 Год назад

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

    • @shopandmath
      @shopandmath  Год назад +1

      Sorry, translation isn’t quite working. I think you’re asking about lubrication
      Depending on the temperatures and if the metal you’re cutting is work hardening. Then you will absolutely need lubrication mostly for cooling so coolant instead of an oil because this is a hand operation doing it in a drill press or a hand drill you generally don’t need oil. Hopefully this helps.
      Ray

  • @leegates3072
    @leegates3072 Год назад +2

    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.

    • @shopandmath
      @shopandmath  Год назад +1

      I never thought of using a file.
      Thank you for sharing. Much appreciated.
      Ray

    • @russelldold4827
      @russelldold4827 Год назад +1

      HSS Centre drills and spotting drills are also useless.
      I have had good results using the diamond file on a Leatherman to touch up the edges on carbide tips - I've carried one on my belt for 35 years. If you need to reshape the carbide, the diamond grinding wheel wins.

    • @shopandmath
      @shopandmath  Год назад +2

      @@russelldold4827 learn something new today I didn’t know that the Leatherman came with a diamond file. I will have to see if mine has one
      Thank you for sharing
      Ray

  • @johnmoss7227
    @johnmoss7227 15 дней назад +1

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

    • @shopandmath
      @shopandmath  10 дней назад

      About 50 people commented on this already and they’re correct and you’re correct. I originally had a different title for this video and I was using a new program or software called tube buddy
      It changes the names of the video to produce better algorithms or something along those lines and it also told me to change the colours of the thumbnail I like trying new things so I tried it out and this is what it came up with so that’s the title of the video
      And I can’t remember what the original title was called now that I’m trying to think about it
      Thank you for commenting and thank you for taking the time to comment. It is much appreciated.

  • @philcook9967
    @philcook9967 16 дней назад +1

    The title is missing an ED (hardened)

  • @timmym9149
    @timmym9149 17 дней назад +1

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

    • @shopandmath
      @shopandmath  10 дней назад

      I did not use coolant or oil. Originally I was going to do this using hand drill
      Creating the proper geometry on such a small drillbit seems to be getting a little bit more difficult with age the video might have me buying the bits premade from Dewalt or Milwaukee

  • @brad2548
    @brad2548 14 дней назад +1

    Wouldn't a cutting fluid be in order ?

    • @shopandmath
      @shopandmath  9 дней назад

      You are correct I should’ve used some cutting oil

  • @trebushett2079
    @trebushett2079 Год назад +4

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

    • @shopandmath
      @shopandmath  Год назад +1

      You are 100%, correct?
      I was just trying to do a simple comparison on material compared to other materials
      And could’ve done a better job doing so
      thank you for taking the time to comment. It is much appreciated.
      Ray

  • @michaelsheppard4227
    @michaelsheppard4227 Год назад +2

    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.

    • @shopandmath
      @shopandmath  Год назад +2

      I love this type of challenge
      If you use a guide plate, you can drill the hole so precise that you can use the same quarter 20 taped hole
      if you use a guide plate, you can drill the hole so precise that you can use the same quarter 20 tap hole
      Let me know how this project goes
      Ray

    • @michaelsheppard4227
      @michaelsheppard4227 Год назад +1

      @@shopandmath I got them out with the dremel last night. Had to drill out hole to 5/16 but it's all good. It took forever to cut that ease out out. I can't believe 1 dremel bit done it though. Now to re-thread it tonight and then put back together and get back on the water.

    • @JMP1649
      @JMP1649 17 дней назад +1

      @@michaelsheppard4227 In future if same problem, consider left twist drill bit. If broken bolt not too tight in threads left twist drill bit can back out broken bolt by drilling in reverse rotation.

  • @user-ox6nc6ly7f
    @user-ox6nc6ly7f 17 дней назад +1

    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.

    • @shopandmath
      @shopandmath  15 дней назад

      Thank you for sharing and thank you for taking the time to comment. It’s much appreciated.

  • @alext8828
    @alext8828 11 дней назад +1

    I didn't understand the positive and negative angle thing.

    • @shopandmath
      @shopandmath  11 дней назад

      when we’re talking about angles through generally three angles that people are going to talk about a positive angle will be going towards the backside of the cutter. The neutral angle would be perpendicular or 90° to the cutting angle and a negative angle would be a angle that leans towards the cutting edge.
      It is a little difficult to describe. I hope this helps.
      Ray

  • @kriseckhardt5148
    @kriseckhardt5148 8 дней назад

    Diamond wheel turning enormously too fast! Otherwise a great video. Thank you sir!

  • @billmorgan6110
    @billmorgan6110 Год назад +1

    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
    ruclips.net/video/dWEN_MxhGqQ/видео.html
    * Video: [2:17/9:57] Spade Drill used to drill "soft steel".
    How to drill harden steel
    ruclips.net/video/kX8Te5ch1Z0/видео.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 ?

  • @chronokoks
    @chronokoks День назад +1

    I thought this video shows a technique how to harden steel with "drill hardening" process. Lmao

    • @shopandmath
      @shopandmath  День назад

      sorry about the misleading title as hard as it is to believe I didn’t make the title it was generated through tube Buddy, which is a RUclips making program
      I guess I could make a video on friction welding
      Thank you for commenting and thank you for taking the time to comment. It is much appreciated.

  • @davidalbright7335
    @davidalbright7335 Месяц назад +1

    How to drill HARDENED steel.

    • @shopandmath
      @shopandmath  Месяц назад

      The exact name of the videos is chosen by the algorithm, including the spelling to get the most views
      Seems a little bit crazy but it also works

    • @davidalbright7335
      @davidalbright7335 Месяц назад

      @@shopandmath , I was speaking about the opening graphic. It also mentioned "Harden Steel." No biggie. Just a misspelling. Great information to keep people from burning up drill bits and work hardening their project material.

  • @tejat.s.k4707
    @tejat.s.k4707 7 месяцев назад

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