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I was building a mount for my custom bobber. My 1/4" carbide drill bit broke off into 3/4" plate of steel.

How do I remove it?

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  • Do you have a pic? What is the bit made of? – DucatiKiller Jan 11 '16 at 23:53
  • Hey, where you been? Did you ever get that thing dug out? – DucatiKiller Mar 19 '16 at 2:43
  • @DucatiKiller Welding was not ideal for this tiny spot. I ended up smashing it through. – Jonathan Musso Mar 19 '16 at 13:49
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If you have a welder.

Weld a metal rod to the top of the drill bit at a 90 degree angle from the drill bit.

You can then use the rod as a lever to turn out the drill bit in reverse. You may want to take a hammer and punch and hammer on the end of the drill bit a few times to loosen it.

How much of that drill bit sticking out?

IMO opinion, even if it a bit of welding splash gets on the plate, you can grind it off. Looks like a work in progress. If a piece of the bit happens to get welded to the plate, you can grind it a bit to ensure it's free.

I've used the trick on very large snapped bolts but never a drill bit and am unsure of whether or not the bit can be welded to the rod in my scenario.

  • I will try this. The bit is not sticking out at all, it's flush with the plate. – Jonathan Musso Jan 12 '16 at 3:30
  • Brutal, do you think you can pull off the rod without welding the drill bit and the rod to the plate? – DucatiKiller Jan 12 '16 at 3:31
  • I'll have to give it a shot, it's a tight spot for sure. I'm not concerned about the plate so much as to welding the the hole shut..like I said it's not sticking out even a mm. This will be interesting! – Jonathan Musso Jan 12 '16 at 3:37
  • Interested in the outcome, let us know how it worked. – DucatiKiller Jan 12 '16 at 3:37
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The drill bit has flutes (grooves in the sides). Try driving nails into both flutes, then grab with locking pliers and turn. Lubricate with penetrating oil first to help.

On second thought- instead of nails, which are generally very soft steel, use tougher steel pins... the easiest of which to find is the shank of a dull drill bit, everyone has some dull 1/8" bits lying around. You can cut off the fluted part, or just use them as is.

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    Sounds good. I will try this and let you know how it turns out! – Jonathan Musso Jan 12 '16 at 2:59
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For go the previous answers! I used to do it all the time as a Big truck Mechanic. use two lite hammers and two punches half the diameter of the drill flutes(grooves on side of the "drill bit"). Ask a friend to operate one set of hammer and punch you the other set. using the drill flutes You both set punch at opposite directions,close to 90degree angle to broken bit point in opposite direction to original drill operation. Now both of you tap punch with hammer gently (hard hit not needed)try to tap as close to same time as you can. While timing isn't critical it does help! The time you take to gather the tools will take longer than removing the bit! It will screw out backward in about 30 seconds to one and a half minutes. It works absolutely every time. "CB"handle is "CookieMonster"just relax and enjoy the info.

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Ideally, with a heavy duty screw/bolt extractor. If that does not work, here is a helpful walk through I recently came across about how to remove a broken but from an engine block: http://m.lowes.com/pd/SpeedOut-4-Piece-Screw-Extractor-Set/50217437

http://thegarage.jalopnik.com/heres-how-to-remove-a-broken-bolt-without-losing-your-m-1702042621

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    I think since the drill bit is hardened that this would be ineffective. That's the real problem, the hardened bit. – DucatiKiller Jan 12 '16 at 0:25
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    Oops, forgot to post the article. I agree that to get it out you probably cannot use an extractor. You could go to a metal shop and have them try to weld a tab on the end to unscrew it, but because it is hardened you may need to drill the bit out. Yikes! Check out the article thegarage.jalopnik.com/… – Tyler Jan 12 '16 at 0:27
  • OMG, It looks like the metal shavings just went straight into his intake manifold when he drilled?????? – DucatiKiller Jan 12 '16 at 0:30
  • Like I said, yikes! I believe he had to take apart the entire top end to remove the bolt without damaging the engine – Tyler Jan 12 '16 at 0:31
  • The joys of making mistakes. Pain makes us better. lol – DucatiKiller Jan 12 '16 at 0:32
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If the bit isn't well jammed into the hole you might be able to get the tips of some needle nose pliers down the flutes and grab hold of it with that. If you can get hold of it, unscrew it out of the hole. This has worked for me but the bit in question wasn't tight in the hole.

  • While this is a good suggestion (and thus my +1), remember this is only a 1/4" drill bit ... tiny. – Pᴀᴜʟsᴛᴇʀ2 Jan 12 '16 at 23:05
  • The bit I pulled out this way was either 6 or 8mm, can't remember which. That's around 1/4" - 3/8". Also, you don't need to put the plier tips a long way in, a couple of mm can be enough. – squigbobble Jan 13 '16 at 13:51

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