About the Author: Michael Flood


  1. Some basic rules. 1 If it broke when you tried to unscrew it an extractor (easyout) 99% of the time will break in there. 2 You need to know how to find the true center of the bolt, the thread pitch is important here so you can figure out the true center. 3 If someone has already had a go before it comes to you then your problems have just started. 4 If it broke in a blind hole while tightening it may be bottomed out so will not be easyouted. I have drilled out extractors with tugsten drills.

  2. Part 2 Without LH drills I use a conventional drill deliberatley sharpend backwards and just under tapping size, run anticlockwise this will usually work. Hard bolts can be drilled, however you need to keep the speed slow so as to not dull the cutting edge. Last rule, when it has already tried to be extracted and you are told there are no broken HSS drills in there. Dont believe them!! Cheers from John.

  3. hi there,i have some torx head bolts on my engine sump that have rounded,do you think this would work,thanks for videos,love you man,but not in a gay way

  4. I used to work in the toolroom at a plastic injection molding facility. Removing broken hardware is a huge part of the job. By far the worse thing to remove from a blind hole is a broken dowel pin. I was just going to say that you can get easy-outs in sets. They have the appropriate size left-hand drill with them. Most often, the broken stud comes out with the drill and you don't even need the easy-out.

  5. I've been machining various things for more years than I care to remember. I have never seen, or even heard of a left handed drill before I watched your video! Quite true, so thanks for enlightening me. Apart from stud removal, what else are they used for?

  6. it would of been nicer if you had used a REAL scenario of a bolt broken off into a real engine block or something. this mock-up lost credibility when the stud started rotating at first bite at 2:59. however I do agree that a left handed drill bit is far superior to any extractor on the market.

  7. Wow I never knew they made left handed drill bits, I use a similar tecnique with a right hand bit, but with a left hand bit a could double my productivity, thanks for the vid

  8. I need to get broken lug nuts out of my bmw e30. Is it best to start with a smaller big then increase size? Do you apply pressure when drilling? What is the chance this will work since you says it only works sometimes? Is it better if i put a lube on the sides to have a better chance that it will work?

  9. Any technique to centre or flatten the sheared surface of a bolt/stud when it's in the hole and you cannot grind off material to expose/flatten it?

  10. I didn't tackle it myself as it was above my expertise. I took it to an engineering/machinist shop that specialises in building blocks and cyl heads plus fabrication with associated welding. He was able to get it out without having to retap it (I can still use a m6x1.0 bolt in the hole fine). So I do think he ended up welding something on it as the surface looks "Fresh" & cleaned up. Gave me a set of SS M6 bolts so it doesn't happen again as easily.

  11. It only works if the bolts are not rusted!    If the bolts are oily and have been snapped by excessive load then there is a good chance of success.  Some diesel engines are apt to have the flywheels fall-off if there is a smash-up in one cylinder or if they have been slogged for a very long time by the bloke who thinks he saves money by always driving in 5th!.  As the bolts are oily they will come out OK.

  12. I have many years of working on different types of machines . The best way if you have a welding  machine weld a nut to the broken bolt or stud. after it cools down spray on penetrating oil and wiggle the bolt until it starts to move.
    If you have stainless steel to stainless steel and the bolt has frozen you are going to probably have to drill and re-tap the threaded hole.

  13. I need to replace a flange gasket. Can I use this if the bolts are not broken to ensure I don't break them and run into trouble? I will replace them with new bolts but I want to make sure I don't to bring in my vehicle to the shop.

  14. Would you recommend this method over an easyout?

    I have an M6 bolt with bimetal corrosion snapped off flush with an aluminium engine cover. Probably the toughest one I've had to deal with yet. (Bike is japanese obviously).

  15. WHY do they make left handed drills? The only reversible drill I have is my cordless and they haven't been around all that long.

  16. This video doesn't show a real situation but it does actually work. I drill a hole through the bolt first and then step with a LH bit. The first hole warms the bolt up so that when you use the LH bit it will shake things loose

  17. So I see some doubters here, I've been doing marine and industrial repair and maintenance for close to 40 years now and I have a set of extractors and Left Hand cobalt bits in my box. They've saved a lot of work, and made a lot of believers. Drilling the bolt relieves the stress using the LH bit means all of the torque is trying to twist the bolt out and gives you a head start on the easy-out. And yes it works on rusty and bi-metallic corrosion and if you're lucky even on galled SS. Don't count on the last. 

  18. Ok question is there a left hand drill bit or is he just drill in reverse? I ask cause I'm now dealing with a broken bolt that I can't weld a nut on the end as it snapped inside the exhaust manifold.

  19. Left handed drill bit. I honestly didn't think they existed, always thought it was a joke like a left handed screwdriver, sky hooks or striped paint.

  20. Intelligent your method congratulations. I use the following method: By welding machine weld our broken screw. If the screw is inside then we solder it until it protrudes. Spray a little with anticorrosive spray on hot metal .Beat with our hammer. Weld the metal rod and spray again. Small moves up – down until we manage to unscrew the screw. If it broke welds and try again

  21. Thanks I've just bought some centre drills and a set of left handed drill bits… I have some M6 bolts sheared in aluminium to fix, fingers crossed 😀

  22. Great video. For some applications this would work great(such as sheared off bolts). A left handed drill bit would never be able to remove a bolt which is seized in an engine block. Think about the amount of force it takes to get the head of a strong hex bolt(Usually grade 5) to twist off. The drill bit strength will not even come close. I have had broken bolt extractors break on me in the past, a few times. I just uploaded a video showing my solution to a recent problem.

  23. I dont think thats gonna work because 99.9% of the times you need to remove a broken bolt its stuck in there pretty badly. With your method you had a hard time removing a bolt that was obviously loose in there but a little tip anyways, use a drop of oil on the tip of the drill, that helps the drill cutting and biting into the metal.

  24. hi mate I've managed to snap off an M6 stud that was torqued into an aluminium cylinder head at only 10 Nm – it's hard to see why but it just snapped off flush with hardly any torque at all as I was trying to remove it. What diameter left handed bit would you recommend trying to turn it out?

  25. Hi sorry but the bolt that is stuck turns the other way round. Clockwise to loosen it so what drill bit should i use

  26. Thanks for the video. One question. Should the bit used to drill the starter hole be smaller than the reverse drill bit or should they be the same size?

  27. Most people have probably never heard of a left handed screw bit. But, as you have shown in this vid they do exist. 😉 But, probably trying to get your hands on them is hot so easy unless you go to proper D.I.Y specialist. RAPID use to be the BEST for this But, no longer available. So, I have no idea as to where to find or obtain these bits ( MAYBE CLAS OLSON or even E-BAY or AMAZON ) or maybe someone else may know of a place that could have various sizes to do with the job. ANYWAY!!! GREAT tip on this vid for extracting a damaged bolt. 😉

  28. Why is this recommended to me? But still interesting, what about the good old nut wielding to the bolt? Should work out as well,or not?

  29. Can you still use this method if you can't see the bolt but you know for sure it's there? Mine broke off due to over-torquing.

  30. The first method shown was spot on and saved me hundreds of pounds, after overtightening an M6 fastener that snapped on my egr valve. thanks

  31. In the USA, these bits are readily available from you local auto parts store or tool truck.
    Yes, they are a bit spendy, ranging from $50 – 150 or there abouts.
    Do an online search for these examples:
    NAPA sells VG 11119 & VG 11135ZR kits made by Vise-Grip; stocked at a local DC. Other auto parts stores should also be able to get them.
    For bits only, DBLS105 by Blue Point & DMCLM5 by Matco are other examples.
    I would think these would also be available at your local hardware store, but I've had no luck.

  32. yeah,got me some lefty drills and keep them with my screw extracters so as not to mix them with my regular bits…but you're correct, plenty of times the fastener will come out using just the lefty bit!

  33. I've got to try and remove a snapped brake disc retaining screw so could you tell me what size drill and centre drill I will need for a M8x 1.25 or M6x1.25 screw/bolt.

  34. Never new you could get a left handed drill bit,where would you get one from,surely not from your local shop. Handy video though. Thanks for the tip.

  35. does it work on a broken screw stuck into rust?
    I got my screw stuck into the distributo shaft and it's stuck in rust

  36. Look at that best perfect case scenario. Id love to see someone doing one thats rusted all the way shut.

  37. hi what the name of the drill bit you use to start the hole with after u put a center punch marking into the bolts and is the other drill bit left hand drill bit too

  38. Useless video when a bokd breakes is cuz is trusted weak and really stuck there and not even mention if a bit breakes inside for demostration cool real life man u gonna struggle

  39. hi what the name of the drill bit that you use after the center punch put a mark into the metal the drill bit with a point on both ends

  40. i learn it the hard way last time dealing with a wear off screw head by breaking the fixture instead.
    always have both direction of drill sets.

  41. Even better. Take a standard right-hand drill bit and regrind the end into left-hand cut. The flute will be the wrong way around, forcing the swarf back into the hole, instead of ejecting it. This gives a greater grabbing action.

  42. With a left handed drill bit inserted into drill, do you keep your drill set on the tightening position(right/clockwise rotation)?

    I have an 8mm bolt which I will be trying to extract either later today or tomorrow.

  43. UH–I was with you up until you used a RH center drill to begin drilling the hole.  You had just explained it was a mistake to use a RH drill in this situation.  Was there a reason you couldn't have started with a LH drill first?  I assume you used the center drill because it was sturdier for its size, (i.e., less prone to breakage), but couldn't the user just step up to a little larger-diameter LH drill to begin the process (say, 3/16", so it wouldn't snap), then finished the job with an even bigger LH drill?  Thanks.

  44. Love it thanks. Going to try this on a bolt that snapped in my head gasket. Fingers crossed it works or the cars going to the scrap yard in heaven.

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