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  1. #1
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    Help me remove a Stripped Titanium Bolt Head!!!

    I made the mistake of using an old allen wrench to try to remove one of the 5mm bolts that holds an XT crank arm onto the spindle. This is an aftermarket replacement bolt made of titanium. The bolt head is now mangled beyone recognition. (I know - I'm an idiot). THere's no way an allen wrench or a torx wrench or any other kind of wrench will get a grip on the bolt.

    I think my only solution is drill the bolt out, right? I've tried with an extractor set I bought at Home Depot. I can't make any progress though. Is it possible that my drill isn't powerfull enough to drill into titanium? Are there special drill bits I can buy for titanium? Do I need a more powerful drill? Any other solutions????

    I just need to get this crank arm off to replace it and the bottom bracket with new ones.....

    I'd GREATLY appreciate the help!

  2. #2
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    Is any of the bolt's head exposed? Did you use thread locker on it? A picture would help.

    Drilling titanium is a difficult prospect, as it's extremely hard to machine, and is very hard on tooling. I'd do whatever I could to keep from having to drill it.

    Personally, I would remove the other pinch bolt, and then install a long steel bolt in it's place and overtighten it to 140 in/lbs (standard is 132in/lbs). Use the long steel bolt to make sure all the threads in the crank arm are engaged. This will pinch the arm together more, which will hopefully release some or all of the tension on the stripped titanium bolt. Then, if you can, back the stripped bolt out with needle nose pliers or a hemostat. If you can't get any grip, you can try a Craftsman Screw-Out to get additional grip, or you can try JB Welding an allen key into what's left of the bolt's socket.

    Alternatively, you could also cut through the exposed part of the bolt's shaft with a dremel, and then use a hemostat to twist the shaft out of the arm.

  3. #3
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    Quote Originally Posted by bad mechanic
    Is any of the bolt's head exposed? Did you use thread locker on it? A picture would help.

    Drilling titanium is a difficult prospect, as it's extremely hard to machine, and is very hard on tooling. I'd do whatever I could to keep from having to drill it.

    Personally, I would remove the other pinch bolt, and then install a long steel bolt in it's place and overtighten it to 140 in/lbs (standard is 132in/lbs). Use the long steel bolt to make sure all the threads in the crank arm are engaged. This will pinch the arm together more, which will hopefully release some or all of the tension on the stripped titanium bolt. Then, if you can, back the stripped bolt out with needle nose pliers or a hemostat. If you can't get any grip, you can try a Craftsman Screw-Out to get additional grip, or you can try JB Welding an allen key into what's left of the bolt's socket.

    Alternatively, you could also cut through the exposed part of the bolt's shaft with a dremel, and then use a hemostat to twist the shaft out of the arm.

    Thanks for the reply badmechanic.

    No - the none of the bolt is exposed and no I did not use thread locker on it. Should I have?

    Good suggestions. I might give the JB Weld thing a try.

  4. #4
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    Quote Originally Posted by msugma
    No - the none of the bolt is exposed and no I did not use thread locker on it. Should I have?
    No! Thread locker is not required for the pinch bolts. All you need to use there is anti-seize.

  5. #5
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    If you decide to continue drilling, you'll need a carbide tipped or solid carbide drill bit to get through Ti.

  6. #6
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    Zanetti nailed it. Carbide bit, very slow RPM and VERY high pressure with lots of cutting fluid (motor oil will work) is what it takes to drill TI. It's not difficult, just different than any other metal and will destroy your tools if you don't use high enough pressure and very low cutting speed. IF it were me, I'd use a reverse drill bit and hope it grabbed the head and pulled it out as I was drilling. (a set of left hand drill bits were the best purchase I ever made 15 years ago) You can find them at most Ace Hardware stores, or track down a tool truck. A good full service automotive shop will have a mechanic with left hand bits also.

    Can you slot the bolt? You might can get a flat head screwdriver in it. Other than that, try hammering a slightly larger (SAE) hex into the bolt. Other options might be to have someone TIG weld another TI bolt to the end of it. Sure, you'll burn the finish on the cranks in the area, but I suspect they are pretty beat up already. I've done this with Steel and more or less didn't damage the powder coating.
    Or, you can cut the bolt in the middle (If I'm not mistaken, you can get a small dremel wheel in there) However, if you cut the bolt, you may not ever get the threaded end out of the other end of the cranks.

  7. #7
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    Great advice guys! Thanks.

    I'm currently trying the JB Weld solution, giving it a full 24 hours to set. Hopefully that works.

    If not, I think the I'll go back to drilling. Good advice there with the low RPMs and the carbide drill bits.

    I'm not concerned about saving the cranks. They are a solid 6-7 years old. I'm trying to get them off to replace them with some new, nicer ones.

  8. #8
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    I guess some of us thought you were trying to save the cranks. Could use a small grinder on the crankarm and grind off enough material to be able to release the bolt and get the crank off. Keep us posted, and please add some pics of the results.
    Good luck to you!!
    Training on Hills Builds Character, That's How I Got To Be One!

  9. #9
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    If you're not concerned about the cranks, then hacksaw through the bolt by cutting down the slot and through the bolt.

  10. #10
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    Brad's suggestion of slotting the bolt has worked well for me in the past. I had a stripped Ti brake bolt seized onto a Ti brake boss - I had to slot the bolt and use a screwdriver to get it apart. I was also able to save the brakes and the boss.

    I used a Dremel with a generic Craftsman-branded cutting disc.

  11. #11
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    Quote Originally Posted by TigWorld
    If you're not concerned about the cranks, then hacksaw through the bolt by cutting down the slot and through the bolt.
    This is a good thought . It's just a matter of finding a hacksaw blade thin enough to get in there. Will I be able to saw through the Ti?

  12. #12
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    Quote Originally Posted by msugma
    This is a good thought . It's just a matter of finding a hacksaw blade thin enough to get in there. Will I be able to saw through the Ti?
    Dremel tool with an abrasive blade will save your sanity. (this is the cut off I was mentioning earlier)

  13. #13
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    Grab-It is another option. EZouts are more for broken bolts. Grab-its are more for stripped heads. It looks like a router bit that digs in and grabs the head as you reverse,

    Contrary to popular opinion, Ti is not some super material that dulls tools on sight. The main problem is working too fast. If you attack Titanium with the same drill speed you would use on wood you're going to dull the bit in no time (even with lubricant). Titanium is easily work hardened, so work very slow. (if the bit is a blur it's too fast). Carbide can tear through Ti as long as the speed is slow enough,

    Proof of concept? Use an ordinary hand file on titanium and material is removed as if it was mild steel. But if you allow friction heat to get high the material will harden faster than it's being cut. The mistake most people make is thinking that cutting oil is a lubricant. The oil is a coolant, and you want as much as possible.

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    and a enough oil to cover the pump.

    Titanium is no big deal if you are set up for it.
    Life is too short to race through it. When life is a blur, you'll miss the magic.

  14. #14
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    SUCCESS!!!!

    I was able to borrow a friend's Dremel tool. I used it to cut a notch into the bolt head and them hammered in a flat head screw driver. What a relief to get that crank arm off! My new XTR cranks look sweet on my SIR 9 single speed!

    My old XT cranks are still definitley usable too. Those will do just fine on my back up bike.

    Thanks for all the help. mtbr RULES!

  15. #15
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    I made the same bonehead mistake on my relatively new XTR (<2yrs) crank that I was not willing to damage. I tried the Torx bit, JB Weld, Grabit bit and slotting the bolt head with a dremmel but none of them worked. I finally was able to remove the bolt by hammering a larger 7/32" hex socket bit into the smaller stripped 5mm hole and very carefully removing the bolt with a ratchet wrench (gives more torque than regular allen wrench). MUCH faster/easier than drilling Ti and also cheaper than carbide or Grabit bits.

    Lesson: Always use a torque wrench and don't try to "quickly" finish projects when you are rushed.

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