B screw busted allen head off in it?

If the head is exposed I'd use a pair of pliers (vise grips, or knippex) and back it out with that. Easier than using a dremel, and it still leaves you with that option.

dysfunction said:

If the head is exposed I'd use a pair of pliers (vise grips, or knippex) and back it out with that. Easier than using a dremel, and it still leaves you with that option.

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The end of the Allen wrench is stuck in the screw?

I would first try spraying some WD-40 or something on it and try to tease the busted wrench out with a dental pick or something similar.

Then I would try what dysfunction said.

Then I would try the "cut a slot in it" method but, if possible, use a hacksaw blade since the Dremel could wander around and scratch up the derailleur. Probably a good idea to mask it off with duct tape to prevent that in either case. This could actually be pretty difficult since the Allen wrench is made of much harder metal than the screw.

This is why I don't use ball end Allen wrenches.

chucko58 said:

This is why I don't use ball end Allen wrenches.

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The T-allens don't have a ball end, maybe op meant p? In either case though I've never busted a ball or straight allen that I can remember, must have been really torqueing on that b-screw!

Dave- can you get to the screw with a mini vice-grip and just remove it?

J.B. Weld said:

The T-allens don't have a ball end, maybe op meant p? In either case though I've never busted a ball or straight allen that I can remember, must have been really torqueing on that b-screw!

Dave- can you get to the screw with a mini vice-grip and just remove it?

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Nope, not enough head to grab on to , I took the derailer off and tried to go from the under side of the b screw with vice grips not enough room, I ended up being very careful and cut a slot in it and used a flat head and backed it out, and replaced it.

I appreciate the replies.it was a straight allen, about half the head broke in there,