Worn, countersunk allen bolt removal

jordan_217

I'm not a biff and didn't over tighten!!!!

I've managed to completely wear the inner hex part of the allen bolt on my headset top cap. So instead of being hexagonal, it's now a lovely circle. It's a Token Ti countersunk bolt. Don't ask me how the hell I managed this, I was using a decent and fairly new, allen key and it wasn't overly tightened. I turned till I got initial bite/resistance and then just tried a *bit* more and spinny spinny, bye bye hexagon.

I've used the same allen key before and since without any issues whatsover and that includes much greater tightening force.

I can't get any purchase on it with pliers as it's countersunk. I've tried a the allen socket from my torque wrench and a Ritchey torque key and none of them will grip. No success with a larger allen key too. Also tried tapping in a flathead screwdriver but it's just grinding a larger circle, the bolt seems very soft!

Short of borrowing a dremmel and turning it into a phillips bolt what can I do to get it out? Sacrafice an allen key and use something like Araldite, maybe?

Any (sensible) advice would be appreciated.

nicklouse

drill it out. you will not dremell it without cutting the top cap.

new bolt time.

jordan_217

nicklouse wrote:

drill it out. you will not dremell it without cutting the top cap.

new bolt time.

Thanks!

I was hoping that wasn't the only option. I've got another bolt on the way and am in no rush to remove this one as I'm confident the headset fine as is.

Is it worth trying to secure an allen key into the existing bolt first? I'm sure it won't need much turning force to get it out, it's just getting the purchase on the bolt.

Wheelspinner

Loctite? Medium strength on Allen key in head?

lochindaal

Use a flat bladed screwdriver and hammer it into the allan head. Screw it out and replace with a new one

snoopsmydogg

get a torx bit slightly larger than the allen key and hammer it in, hopefully will have enough grip to remove it. will still be new bolt time but saves drilling

Barteos

snoopsmydogg wrote:

get a torx bit slightly larger than the allen key and hammer it in, hopefully will have enough grip to remove it. will still be new bolt time but saves drilling

This.
I have a collection of modded / grinded straight torx keys that can be nicely hammered into rounded hex bolt sockets. It works in 9/10 cases for me.

jordan_217

Cheers for all the responses, will try the torx keys approach first.

I have received the replacement bolt today. Upon inspection it appears that the hexagonal opening isn't really pronounced and looks susceptible to easy wear, in fact it looks more circular than hexagonal. I may source a different bolt rather than encounter the same issue down the line.

Thanks again for the advice.

Smokin Joe

snoopsmydogg wrote:

get a torx bit slightly larger than the allen key and hammer it in, hopefully will have enough grip to remove it. will still be new bolt time but saves drilling

+2.

Never fails.

TheEnglishman

You could try a stud extractor, especially as the 'hole' is already there in the shape of the worn out hex.

Drilling it out could be a nightmare - start with a 2.3mm drill, hope it drills straight, then move to a 4 then a 5mm drill. Then tap the hole out and it *should* come good. However you risk either not drilling the hole straight or worse, snapping the drill bit off :shock: Been there, done that, it's not pretty.

The torx bit sounds a go-er - I'd try that first, then a stud extractor, then drilling.

nicklouse

TheEnglishman wrote:

You could try a stud extractor, especially as the 'hole' is already there in the shape of the worn out hex.

Drilling it out could be a nightmare - start with a 2.3mm drill, hope it drills straight, then move to a 4 then a 5mm drill. Then tap the hole out and it *should* come good. However you risk either not drilling the hole straight or worse, snapping the drill bit off :shock: Been there, done that, it's not pretty.

The torx bit sounds a go-er - I'd try that first, then a stud extractor, then drilling.

A stud extractor is the pain as you would need to carefully drill it so that the toll will fit. But the small tools suck and will break.

Drilling it out is a piece of piss 6mm and zzzz done. Head off . Cap off. Use fingers or pliers to unscrew the unstressed threaded bar.

What. 2 mins max.

ineedalager

We used to use a center punch and hammer to work them loose. Just make a big center punch hole hitting in an anticlockwise direction can shock them free and then once loose the Allen key again. Somtimes you can flatten the top of the bolt back down with a ball pane hammer to make the Allen key fit better.

crankycrank

Try loosening the stem clamp bolts on the steerer tube and twisting the stem anti-clockwise a little. May be just enough to break the bolt free and unscrew easier.

jordan_217

An update on this - I managed to get the bolt out today by tapping in a torx bit and turning the bolt loose with some pliers. Job done.

Thanks again for the tip.