Rounded Nut!

[sportsupdate]

Hi guys. I am attempting to replace my bottom bracket but have been stopped at the first hurdle. The allen key nuts on the left crank have been rounded and are impossible to shift. Any handy tips to remove these without going down the butchering with drilling or grinding or heating with a blow torch route?? The crank is fixed by an allen key type nut on either side which splines the crank onto the axle. Sorry no photos available. The bike is an old Scott Fx2 zero which I am attempting with difficulty to restore. Thanks in advance.

[cyclerUK]

If there is any part of the bolt head sticking up you could try "mole grips" or "stilsons" (pipe wrench.)
Failing that I think it will be drilling.
Another possible option is to use the next size "imperial" Allen key and force it into the rounded hole.
Just might be enough grip to loosen it?
The original bolt will be metric.!

[sportsupdate]

(12-29-2010, 12:16 PM)cyclerUK Wrote:  If there is any part of the bolt head sticking up you could try "mole grips" or "stilsons" (pipe wrench.)
Failing that I think it will be drilling.
Another possible option is to use the next size "imperial" Allen key and force it into the rounded hole.
Just might be enough grip to loosen it?
The original bolt will be metric.!

Thanks for reply. Unfortunately bolt is countersunk so grips not an option. Drill on charge.

Who said biking was easy.