# HELP broken bolt in stem



## sadisticnoob (Dec 6, 2009)

Hi,
While torquing my 3t arx team steam to 5nm using torque wrench, the ti bolt broke off inside the stem leaving a tiny piece jutting off,


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## reptilezs (Aug 21, 2007)

crappy bolts and lack of thread prep. the head is not on the bolt so their should be no tension on the threads and it should come out easy. if it is putting up a fight then the ti has galled. get the vice grips out


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## tihsepa (Nov 27, 2008)

^^^this^^^^
Put a nut on it halfway the thiskness on the nut. Then put another bolt in the nut. Think of it lie you are extending the broken bolt with a nut as a coupler. It should come right out. If not,upgrade oppertunity.


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## sadisticnoob (Dec 6, 2009)

i torqued to 5nm i tried to use a pilers and it was tight


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## frdfandc (Nov 27, 2007)

You going to have to flatten out the end of the bolt with a grinder just to remove the rough edge, then drill the bolt that's left and the use an easy out.


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## tihsepa (Nov 27, 2008)

sadisticnoob said:


> i torqued to 5nm i tried to use a pilers and it was tight


Ok, cut a slot in it and remove with a flat screwdriver.
Do everything you can before drilling or cutting off the little nub thats still above the threads.


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## sadisticnoob (Dec 6, 2009)

hmm gonna to have a try tmr .. most prolly going with the flat screwdriver thingy as i do not have a grinder at home... how the hell do i know that 3t ti bolts are so sucky


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## wibly wobly (Apr 23, 2009)

Funnily enough, I just broke a bolt on the same stem at the back of the thing (around the fork) while doing some headset adjusting. My prob was that there was nothing to grab on to. Out came the bolt extractor kit and in went a steel bolt. Managed to only do a little bit of scuffing to the finish.


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## TomH (Oct 6, 2008)

Use vice grips and turn the stud out. By far the easiest way. 

What torque wrench are you using? It might be out of range for 5 nm bolts.


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## wim (Feb 28, 2005)

TomH said:


> It might be out of range for 5 nm bolts.


The customary 5 Nm assumes steel bolts. A steel bolt is generally stronger than a Ti bolt _if both are the same size_. In general, to make a Ti bolt as strong as a steel bolt, you'd have to increase the size of the Ti bolt and, of course, increase the size of the hole it threads into. For cost reasons, that's not often done.

In short, the Ti bolt wasn't "sucky." Breaking it was just another one of those instances where substituting Ti for steel _without a design- and/or specification _change can cause trouble.


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## PlatyPius (Feb 1, 2009)

wim said:


> The customary 5 Nm assumes steel bolts. A steel bolt is generally stronger than a Ti bolt _if both are the same size_. In general, to make a Ti bolt as strong as a steel bolt, you'd have to increase the size of the Ti bolt and, of course, increase the size of the hole it threads into. For cost reasons, that's not often done.
> 
> In short, the Ti bolt wasn't "sucky." Breaking it was just another one of those instances where substituting Ti for steel _without a design- and/or specification _change can cause trouble.


^ This.

Since I learned this back in the 90s with mountain bikes, I assumed everyone would know it. Ti bolts should always have Ti prep (Finish Line makes it) and the torque is less than for steel bolts.

Yet another reason I think torque wrenches are over-used/relied upon. Not the wrench's fault, of course, it's a lack of proper information. In this case, you probably would have been better off just tightening it by hand to what felt right.

*** Just went and checked the 3T site. They say 5Nm. That really doesn't seem right. Also, this seems to be a common problem. Do a Google search on "bicycle stem titanium bolt torque" and you'll find lots of stories going back a few years. FSA and 3T seem to be the main culprits.


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## Kuma601 (Jan 22, 2004)

As above, cut a slot into it and use a flat head screwdriver to unscrew it. 

Once you get the broken bolt out, check to see if the threading is complete by putting another bolt into. If it stops short, then you'll need to chase the threads with a tap. I suspect that the threads and or lack of prep, caused it to seize and shear as it did.


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## rx-79g (Sep 14, 2010)

PlatyPius said:


> ^ This.
> 
> Since I learned this back in the 90s with mountain bikes, I assumed everyone would know it. Ti bolts should always have Ti prep (Finish Line makes it) and the torque is less than for steel bolts.
> 
> ...


Torque settings are not based on material, but use. A stem needs the bolts tightened enough to hold the handlebar - regardless of what the bolt is made of. If 3T is going to include the bolts, then someone thought they were strong enough for this use. 

So it becomes a question of bad engineering or bad assembly (like not using anti-seize).

There is something to be said for the old way of building things without blind threaded holes. But using ti bolts is kinda silly.


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## Ventruck (Mar 9, 2009)

Lucky me, never had that happen with my ARX Team through my several installations. Always feared I'd have that issue with the bolts, but then again I never exactly followed the 5Nm line since I didn't have a torque wrench. Just went by feel.


Eh, I wasn't much help. >_>


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## sadisticnoob (Dec 6, 2009)

I used to go by feel till my hands decided to be itchy and use a torque wrench . Guess it's new stem time if I fail to take it out tonight (its morning here) and I have a race this weekend!


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## rx-79g (Sep 14, 2010)

Something you might try:

Since aluminum expands more quickly than titanium, if you put the whole stem in a 200 degree oven, they try pliers, you might find the bolt is much easier to turn than it is now. 

I got a steel pin out of a blind whole in an aluminum forging this way.


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## sadisticnoob (Dec 6, 2009)

rx-79g said:


> Something you might try:
> 
> Since aluminum expands more quickly than titanium, if you put the whole stem in a 200 degree oven, they try pliers, you might find the bolt is much easier to turn than it is now.
> 
> I got a steel pin out of a blind whole in an aluminum forging this way.


personally i am not so sure whether i shld try this because expanding and then contracting the metals would lead to a slight shift of molecules inside the material. This might be okay for home usage product but not something i would like to depend on my life on when im travelling ...

but isnt ti tensile str stronger than AL tensile strength ?


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## GirchyGirchy (Feb 12, 2004)

sadisticnoob said:


> personally i am not so sure whether i shld try this because expanding and then contracting the metals would lead to a slight shift of molecules inside the material. This might be okay for home usage product but not something i would like to depend on my life on when im travelling ...


In that case I hope you never drive a car.


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## rx-79g (Sep 14, 2010)

sadisticnoob said:


> personally i am not so sure whether i shld try this because expanding and then contracting the metals would lead to a slight shift of molecules inside the material. This might be okay for home usage product but not something i would like to depend on my life on when im travelling ...
> 
> but isnt ti tensile str stronger than AL tensile strength ?


The temperature of boiling water is hundreds of degrees below the heat treatment temperatures of aluminum, ti or steel. If you leave your bike in the car the stem will get that hot. Powdercoating is hotter than that.


Ti has a higher tensile strength than Al. That has nothing to do with their thermal rate of expansion. 

When you have two things of identical size at room temperature (like a threaded hole and a bolt lodged in it), they won't be the same size at other temperatures if the two things expand at different rates. Since aluminum expands more per degree, the hole will get larger faster than the bolt will, making it loose and easier to turn with vice grips.


Don't let those molecules scare you.


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## sadisticnoob (Dec 6, 2009)

thx for all the advice and help, the offending bolt was removing with a pair of those big pilers.Stem is saved and still usable.


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