Help! Rounded off Allen bolt stuck!

[drystonepaul]

Re:

That's an easy one Doug.

See my first post.

If you were anywhere near my workshop I'd sort that for you in 15 minutes for a packet of biscuits.

 

[drcarlos]

Re: Re:

I had the very same problem yesterday while trying to get some rotors off some new secondhand wheels. Both rotors had one stuck bolt that the previous owner had kindly rounded.

Can you cut a slot for a screwdriver - and perhaps tap it round? Or use pliers on it (probably not from the sounds of it)? Weld or epoxy an allen key to it?

In the end I managed to bend and rotate the both rotors a little which loosened the bolts enough that I could get the pliers on them.

Hmm no the bolt is sunken flush with the arm so cant cut a slot and pliers no chance...looking at how mangled the head is I doubt epoxy would help either! See pic

I would use Pauls method on that with the modification of using an easi out once I got to about a 3 or 4mm drill. I would drill as much as I could first and use the largest easi out I could fit.

Carl.

 

[onegoodbike]

Re:

I've had a similar issue with small titanium socket head bolts in the past. I bought a 3mm-ish? extractor from a local hardware store, drilled a small hole into the centre of the offending bolt and wound the reverse thread extractor in with it fitted in a tap holder, it worked like a dream and only cost a couple of quid . Matt

 

[wookiee]

Re: Re:

That's an easy one Doug.

See my first post.

If you were anywhere near my workshop I'd sort that for you in 15 minutes for a packet of biscuits.

Well I guess the good news is that you think this is an easy job...lets just hope its easy for me! I would happily buy you a tin of biscuits...even Tesco's Finest! What do you think to the drill a pilot hole then use a screw extractor? With my history of being "over zealous" with simple jobs and making them worse!

Doug

 

[B3]

Re:

If you haven't already, tighten the other bolt before trying to loosen with an easyout, it will take some of the load off the bolt.

 

[wookiee]

Re: Re:

If you haven't already, tighten the other bolt before trying to loosen with an easyout, it will take some of the load off the bolt.

Good tip thanks

 

[Grannygrinder]

Re:

I expect to maybe shot down in flames here but.....
If one of the pinch bolts is loose can you now loosen the BB cup on that side with the aim of sliding the arm off the shaft and so releasing the tension on the bolt?
I think it will be immediately apparent if the arm is lose enough to slide off.
Well thats what i'd try anyway

*Duck and cover*

 

[wookiee]

Re:

Not sure if with one bolt still tight that it would slide off the shaft...will try later though. If that doesnt work I have the extractor and drill bits on standby!

 

[drystonepaul]

Re:

My experience with those screw extractors hasn't been great. With high quality stainless steel bolts found on many bike components the material is a bit too hard for the extractor to 'bite' into them.

They are fine on aluminium alloy bolts and lower grade steel in terms of biting into the bolt and getting enough purchase to unscrew them. You can end up just shearing the bolt cap off.
if you haven't already pre-drilled a nice clean centred hole down the bolt shaft, then it is much more difficult to then get a hole drilled in the end of a broken bolt.
That said, once the bolt cap is gone then the tensile load on the thread will no longer be an issue so the remainder of the bolt shaft usually turns if you can get hold of it.

I'd definitely recommend using that 2mm drill bit first as a fail safe. A bit of light oil on the tip of the drill bit helps too.

You'll be fine Doug. Drilling out titanium bolts on expensive titanium frames is much more nerve wracking.

 

[Neil]

Re: Re:

My experience with those screw extractors hasn't been great. With high quality stainless steel bolts found on many bike components the material is a bit too hard for the extractor to 'bite' into them.

They are fine on aluminium alloy bolts and lower grade steel in terms of biting into the bolt and getting enough purchase to unscrew them. You can end up just shearing the bolt cap off.
if you haven't already pre-drilled a nice clean centred hole down the bolt shaft, then it is much more difficult to then get a hole drilled in the end of a broken bolt.
That said, once the bolt cap is gone then the tensile load on the thread will no longer be an issue so the remainder of the bolt shaft usually turns if you can get hold of it.

I'd definitely recommend using that 2mm drill bit first as a fail safe. A bit of light oil on the tip of the drill bit helps too.

You'll be fine Doug. Drilling out titanium bolts on expensive titanium frames is much more nerve wracking.

Another vote for that - I've not had great experience of easy-outs, either. They can sometimes make a bad situation even worse.

I'd be tempted to try and drill it out as has been recommended, here. Just one question - is there space in the gap to use a hacksaw blade to actually cut the bolt, so you could at least get the crank off the spindle? Then it would be easier to drill out when you could put it in a vice or something - or even better, if you've got access to a pillar drill.