Undersized 8mm hex socket screws (due to rust)

[Will!]

I've got an 8mm socket screw holding in the send and return lines of a PAS rack. It's gone rusty and an 8mm hex bit doesnt fit anymore. I don't fancy drilling a hole in the end for a screw extractor, I can't really get a drill to it. It's deep between the two hydraulic lines, a drive shaft, the steering rod ends, between the subframe and a fuel tank.

Logic would say get a 5/16" hex bit and try that but before I drop some ££ on a whim for something I'll never use again, are there any other suggestions?

 

[julianf]

Hammer time, surely?

If you reckon it'll break something, what about some acid in a pipette? Even harpic lime scale remover (toilet cleaner) will do, if you have nothing else to hand.

 

[angellonewolf]

if you use some thing smaller i dought the rust will take any power will just crumble the bit will slip and it rounding out the hole

can you hammer the 8mm in there ?

 

[keithski122]

Torx bit sometimes works, or these:- https://www.ebay.co.uk/itm/22699666...HLXuAuVWl7aqU9KfFlUQAb2xDkdsu7Q0aAujFEALw_wcB

 

[Hood]

Hammer in the 8mm as said, if it rounds then hammer in a suitable sized Torx bit.

 

[m_c]

Find whatever the next slightly bigger Torx/Ribe bit is, and hammer it in.

 

[Mark 5]

I've got an 8mm socket screw holding in the send and return lines of a PAS rack. It's gone rusty and an 8mm hex bit doesnt fit anymore. I don't fancy drilling a hole in the end for a screw extractor, I can't really get a drill to it. It's deep between the two hydraulic lines, a drive shaft, the steering rod ends, between the subframe and a fuel tank.

Logic would say get a 5/16" hex bit and try that but before I drop some ££ on a whim for something I'll never use again, are there any other suggestions?

Cut or grind a slot into the head, use a flat blade or use the power of cordless hammer with a flat head bit to turn/loosen the head.

 

[ajlelectronics]

Torx bit hammered in.

 

[dobbslc]

Torx bit sometimes works, or these:- https://www.ebay.co.uk/itm/22699666...HLXuAuVWl7aqU9KfFlUQAb2xDkdsu7Q0aAujFEALw_wcB

Another tool I didn't know existed and that I now must own

 

[ajlelectronics]

Another tool I didn't know existed and that I now must own

Irwin do a set too. I use their set of nut removers too, it has been so useful.

 

[keithski122]

Irwin do a set too. I use their set of nut removers too, it has been so useful.

I just picked a link to the first set I could find, irwins probably better quality. The nut removers have been lifesavers to me at times.

 

[tom2207]

mac do a set of extractor sockets for hex , they are mighty ,,,

 

[Matchless]

Torx bit often works, and the hammering helps.

 

[premmington]

Irwin do a set too. I use their set of nut removers too, it has been so useful.

I got the full sets of these Irwin external nut removers - from tiny ones to big stuff.

They do go blunt after a lot of use - but never smashed one and they have had some hard hammering.

The are ace - got me out of the "poop" loads of times.

 

[Shedendman]

I to vote for those Irwin's,i have the small 5 piece set in imperial 3/8 drive,been battered to hell and back,still going strong

 

[Agroshield]

The other thing that will halp a great deal is a manual impact driver. The way it us used (hammering it) will assist the self-tightening action of the bits. It will aggresively reduce cam out.

Draper 81519 6-Piece Impact Screwdriver Set : Amazon.co.uk: DIY & Tools

Free delivery and returns on all eligible orders. Shop Draper 81519 6-Piece Impact Screwdriver Set.

www.amazon.co.uk

They have a 1/2" square male end on them, so adaptors to anything (1/4" hex, for example) are easy to find.

 

[Will!]

Thanks for all your suggestions - I was a bit wary of banging a tool into a fastener in an aluminium hole.
I got talking to my old man this morning and he suggested grinding the 8mm down until it fits, classic toolmaker approach.
I've now got a 7.3mm hex driver which fits snug.

 

[Hood]

Thanks for all your suggestions - I was a bit wary of banging a tool into a fastener in an aluminium hole.
I got talking to my old man this morning and he suggested grinding the 8mm down until it fits, classic toolmaker approach.
I've now got a 7.3mm hex driver which fits snug.

My worry with that is rust is soft so if it was originally an 8mm hex and you now try and undo with a 7.3mm hex it will likely just round.

 

[doubleboost]

Hammer in a torx bit .
Urwins work as well .
They will have copper or aluminium sealing washers .
Hammering will crush these and help release them .

 

[Will!]

My worry with that is rust is soft so if it was originally an 8mm hex and you now try and undo with a 7.3mm hex it will likely just round.

It's a weird rust, not the flakey crust that normally ends up on fasteners under cars, the screw is black and speckled with dots of rust. I don't know if its because it's covered in hydraulic fluid that it's not gone grim; or because the screw was originally plated with something (the replacement looks dull grey, almost like it's galvanised, but not quite). It feels (haha!) like it's still a cap screw rather than cheese. I'll see whether the torx bits I do have will do the job first.

Hammer in a torx bit .
Urwins work as well .
They will have copper or aluminium sealing washers .
Hammering will crush these and help release them .

The screw is item 13 below, the line seals are 17 and 18 (regular NBR o-rings with a backup ring), the fittings have flanges on them that are clamped in place by 12. I guess the plate will spread the impact across the face on the rack, rather than it just bashing threads.

Mildly cheesed off by how it seems that someone previously replaced the lines on the rack but managed to not bother replacing, or damaged, the seals on the feed lines putting it back in the car.