Help! Stripped head on Hex Bolt

[chasdrury]

Bit of a problem, this one!

I am trying to get my passengar seat out, there is a bad lump under the carpet - I think some soundsproofing has moved, or something!

Anyway, the seats have been out before by Audi when 2 of the motors failed. 3 hex bolts out fine, but the last one I come to, no head. Completely round. (how did they retighten a stripped bolt), and how do I get it out... I have tried dremelling a groove to use with a flathead screwdriver but I think the bolt is hardened metal...

Any help appreciated!

Chas

 

[Carpy25]

use a star bit and hammer it in or grip the blot with a GOOD set of mole grips


Rob

 

[quattrojames]

Or you buy screw extractors (from Halfords I expect) which will bite into the screw head as you undo it.

 

[howdy quattro]

molegrips! always a winner, or be a real bodger with ur dremel and just cut the bolt head off!!

 

[chasdrury]

Cheers for the ideas, guys

Can't get molegrips in there, and it's too tight for pliers too...

Think I am going to try to get an extraction tool from Halfrauds.

If I cut the head of the bolt off, I wouldn't be able to get a new bolt it!!

Chas

 

[quattrojames]

Only you will know the answer to this, but if you do cut the bolt off, then the seat will come out which might expose enough thread of the bolt to get a good grip with the mole grips ...?

Or at least you will be able to drill the bolt and give yourself a better chance with the screw extractors?

 

[J7USS]

Like QJames said, If you take the head off the bolt then when your seat is out you should have minimum 6mm to play with, least then you can get the grips on it easier!
It may be too tight but I filed one bolt (not seat though) either side and made a nice shape for a spanner, worked a treat!

 

[Macduff]

Can you hammer an old socket onto it and loosen it that way?

Or if there's space and you can protect the interior, you could get a nut welded on and then use a socket on the nut.

 

[ScottyP45]

There are also spanners available from halfrauds called "metrinch" that have a wave shape instead of flats and grip even rounded bolts, you might be able to buy a single size im sure, or theres a universal plumber's spanner with a swivel head and a flat serrated "tooth" that pivots into the head thru a slot, that tightens as you turn it and it will take out even a round bolt shaft with no head, but the spanner head is quite broad and not always easy to fit in tight spaces.

You could maybe smear mixed up araldite into a small socket that fits it, and push it over the bolt head leaving a tiny gap at the bottom so it doesnt touch down totally, let it harden over night, then stick the ratchet on it and undo..

One last option is to go to a garage that has a mig or tig welder, slide the seat back to expose the bolt if you can, and they can sit a nut on top of the worn one and mig it inside the thread to the old bolt head, it will get a good weld if you can do this and the new nut on top can be easy unscrewed as soon as the weld cools down, taking the bolt with it, the heat will have loosened it somewhat too and it would only need a short dab from the mig so no burning to worry about.

Just a few ideas, btw I like j7uss's suggestion about filing a flat on each side and using a smaller spanner