Omega Owners Forum

Chat Area => General Car Chat => Topic started by: JesterRT on 06 March 2011, 11:18:56

Title: Removing a rounded hex bolt
Post by: JesterRT on 06 March 2011, 11:18:56
I've got a problem I need to solve today.  There's a 6mm hex bolt (male drive) which currently attaches my front brake caliper on my Polo.  Whoever has been in there before has made a right mess of rounding the thing out.  What are my options to remove it?  I do have access to welding equipment, but that seems extreme.  I've thought about grinding flats on to attempt getting a spanner on.

Just about had enough of this car - bought as a cheap runner and it's turned into a money pit.  Alternator, two wheel bearings, gearbox appears to be an issue (bloody clunky gear shifts), discs/pads.. and more.

May not be a problem soon as I may just have to give up and rent somewhere closer to work during the week given the current trend of petrol prices.  *sigh*  - one of those days...
Title: Re: Removing a rounded hex bolt
Post by: Lazydocker on 06 March 2011, 11:22:30
If you can get in there you may be able to use a pair of Stilsons (Plummer's wrench) on it as they grip tighter as you use them :-/ :-/

Belt a smaller Impact socket onto it?

As you say, grind flats. Or weld a nut onto it, although I would imagine that'll be a right PITA
Title: Re: Removing a rounded hex bolt
Post by: JamesV6CDX on 06 March 2011, 11:25:22
What size is the bolt?
Edit - I meant, what size is the head on the bolt)

I have some sockets that are guaranteed to remove it!
Title: Re: Removing a rounded hex bolt
Post by: JesterRT on 06 March 2011, 11:26:40
It's a 6mm, but not the traditional hex head, it's countersunk hex, so think allen key...
Title: Re: Removing a rounded hex bolt
Post by: Lazydocker on 06 March 2011, 11:29:20
Quote
What size is the bolt?
Edit - I meant, what size is the head on the bolt)

I have some sockets that are guaranteed to remove it!

Stud Extractors ;) ;)

That is another option but decent ones aren't cheap... I've got some that would remove it too but he's too far away from me ;)
Title: Re: Removing a rounded hex bolt
Post by: JamesV6CDX on 06 March 2011, 11:33:12
Quote
It's a 6mm, but not the traditional hex head, it's countersunk hex, so think allen key...

Can you measure the diameter of the head of the bolt (from one outside edge to the other - not across the hex bit)

I can then see if I've got anything to help
Title: Re: Removing a rounded hex bolt
Post by: Andy B on 06 March 2011, 13:28:23
Quote
It's a 6mm, but not the traditional hex head, it's countersunk hex, so think allen key...

I assume this is the type you're tyring to undo  :-/
(http://www.fastfixdirect.co.uk/images/categories/Socket_Countersunk_SC_300.jpg)

Either batter a slightly bigger imperial socket drive allen key in, or a small chisel on the main part of the head or drill the head off. You'd then be left with a very short bit of bolt that you can use vise-grips on, as there is now no tension left on the bolt it should ::) unscrew easily.
Title: Re: Removing a rounded hex bolt
Post by: bigegg on 07 March 2011, 10:42:41
In the past I've used a small cold chisel with a screwdriver-shaped head, and a hex shank. (home-made)
bash the chisel into the head to make a slot, then put a spanner on the shank
might work with a slot headed screwdriver if the head is soft enough.

or drill down the centre with a 5.5mm drill, tap to m6, and loctite a 6mm hex head screw into it
Title: Re: Removing a rounded hex bolt
Post by: Malcolm_D on 08 March 2011, 13:31:35
Apply plenty of penetrating fluid and allow it to soak in first. Use a sharp centre punch on the outer edge, not too close, create an indentation and then angle the punch so the the head is being forced anticlockwise. The punch provides an impact as well as driving it round.  :y