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Titanium hex bolt problem

stevenbstevenb Posts: 717
edited December 2009 in Workshop
Just fitted a brand new KCNC stem on tonight and the top bolt on the stem/steerer tube has decided it doesn't like allen keys and round off .
I put the allen key in, turned it to loosen it and a big spark came out and has now stripped the hex sides away. :shock:

How the **** did that happen? :shock:
Never seen that before....ever.

Dunno what to do now.
Any suggestions?

Posts

  • I have done that with a ritchey stem with Ti bolts, soft as soft cheese

    I used a hack saw to cut the bolt straight across, then stuck a flat head screwdriver in and unscrewed it
  • stevenbstevenb Posts: 717
    Good idea.
    :? I thought titanium was hard as anything?
  • I believe that titanium bolts MUST be installed with anti-sieze compound. If not they will stick and be extremely difficult to remove.
    Titanium is very tough and i am surprised that you can hacksaw a slot into it and even if you did it should be very difficult to unscrew.
    Did you remove the edges from the allen key or the bolt head?
  • stevenbstevenb Posts: 717
    The edges have been stripped from the bolt head. :(
  • Pure titanium (comercially pure CP) if no harder than mild steel.
    Alloys of titanium (6/4 3/2.5 etc) are slightly harder than mild steel.

    It is possible that people confuse tungsten with titanium ... or is it titanium with tungsten.... Tungsten is very hard and make hard wearing Tungsten carbide cutters.

    Or maybe people confuse titanium metal with Titanium Nitride (TiN technically a ceramic). Titanium nitride can be used as a hard wearing coating on cutting tools (such as tungsten carbide).

    Titanium can be cut using a new / sharp hacksaw blade. Although after only a few strokes the blade will start to cut less well, but will still cut. It can be drilled and tapped with high speed steel with care and sharp tools.

    Commercially Pure titanium has very poor mechanical properties : strength, hardness etc.
  • DaimlerDaimler Posts: 215
    A trip to the LBS was a no go. :cry:

    The bolt has stuck itself tight.
    The steerer tube expander is stuck and a tiny fracture has started to appear on the steerer tube but it could be the lacquer thats cracked and not the tube itself.
    They couldn't twist it off and they would have been there all day tryinmg to hacksaw through the bolt.
    i do have two new blades at home I can use.
    It's a case of getting the stem off, check the steere tube is ok and then seeing if I can drill out the remaining bolt bits.

    Fingers crossed.
    Planet X RT-57 custom build
  • DaimlerDaimler Posts: 215
    A trip to the LBS was a no go. :cry:

    The bolt has stuck itself tight.
    The steerer tube expander is stuck and a tiny fracture has started to appear on the steerer tube but it could be the lacquer thats cracked and not the tube itself.
    They couldn't twist it off and they would have been there all day tryinmg to hacksaw through the bolt.
    i do have two new blades at home I can use.
    It's a case of getting the stem off, check the steere tube is ok and then seeing if I can drill out the remaining bolt bits.

    Fingers crossed.
    Planet X RT-57 custom build
  • DaimlerDaimler Posts: 215
    I'm just going to continue with the hacksaw method.
    That should get through the bolt ok.

    Fingers crossed.
    Planet X RT-57 custom build
  • stevenbstevenb Posts: 717
    All done.

    The stem is off.
    I hacksawed through the bolt not problem. I knackered one blade but an 80p Wilkinsons economy special hacksaw did the job.
    I got a screwdriver in the clamp gap and the bolt head pinged off somewhere and left the broken remains in the other side.
    At least it's off and there is no damage.

    Had a nice result with the shop I bought it from offering to help so I'm sending the stem back to them and they will try to extract the remaining bolt piece.

    They also sent me out another one today at a special reduced price for Saturday morning delivery......so I might end up with 2 good stems. :)

    I feel happier now.
  • stevenbstevenb Posts: 717
    Well.....I should have been more patient and not ordered another new stem!

    I have extracted the remaining bolt by using a small screwdriver and a small file. I think the problem was the clamp was putting undue tension (due to being overtightened) on the bolt preventing it from undoing.
    I had to get a tiny file in to deburr the exposed edges so that it would pass through to the non-threaded part of the bolt clamp hole but that was easy!

    I have since painted the stem so there are no unsightly scratches on it at all.

    I will contact the shop and see if I can return the new ordered stem for a refund.

    Titanium Bolt 0 - 1 Steve and his Bike :lol:
  • WappygixerWappygixer Posts: 1,396
    All the more reason to buy a torque wrench.
  • stevenbstevenb Posts: 717
    Exactly. 8)
  • CP Titanium is similar to SS304. The same methods which you will use to remove any broken bolt can used for titanium.
  • pilot_petepilot_pete Posts: 2,113
    And install with coppaslip grease on the thread!
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