Broken extractor?

[MikeBs]

Hi, I have a sheared M8 bolt stuck in an aluminium alloy casting. I only have access to one side of the casting so cannot get at the back of the thread.
Managed to drill it through and get an extractor in and just as it started to move the extractor broke.
It’s all below the surface so cannot get hold of anything to try and turn it out.
I’ve just watched a YouTube video of someone removing a jammed extractor with a small diamond hole cutter. Anyone ever done this or have any other suggestions?
Regards Mike

 

[JEZGUZ]

Carbide or diamond burr in something like a Dremel or small die grinder will get through the extractor. All the heat an vibration should make the bolt easier to remove, tap the tine end of a file into the hole and use that as a screwdriver, they're not hardened so won't break unlike those extractors. When you've finished, throw the rest of the extractors in the bin

 

[premmington]

Hi, I have a sheared M8 bolt stuck in an aluminium alloy casting. I only have access to one side of the casting so cannot get at the back of the thread.
Managed to drill it through and get an extractor in and just as it started to move the extractor broke.
It’s all below the surface so cannot get hold of anything to try and turn it out.
I’ve just watched a YouTube video of someone removing a jammed extractor with a small diamond hole cutter. Anyone ever done this or have any other suggestions?
Regards Mike

Out with a DC TIG welder - washer over the hole and put blobs of weld on whats left of the extractor - then weld a nut on it.

-----------

I had to do this last week with a broken M8 tap - I was dumb enough (and don't laugh) to put a tap in a battery drill and attempt to thread loads of holes - plan was going OK - using the numbered adjustable clutch on the drill - till the tap broke...

 

[Bornfree]

Out with a DC TIG welder - washer over the hole and put blobs of weld on whats left of the extractor - then weld a nut on it.

-----------

I had to do this last week with a broken M8 tap - I was dumb enough (and don't laugh) to put a tap in a battery drill and attempt to thread loads of holes - plan was going OK - using the numbered adjustable clutch on the drill - till the tap broke...

A case of more haste less speed.

 

[Dilkris]

Cheap extractors are guaranteed to cause such problems - bin them !!! These are one item in your tool box you do not want to go cheap on.

 

[MikeBs]

Carbide or diamond burr in something like a Dremel or small die grinder will get through the extractor. All the heat an vibration should make the bolt easier to remove, tap the tine end of a file into the hole and use that as a screwdriver, they're not hardened so won't break unlike those extractors. When you've finished, throw the rest of the extractors in the bin

The diamond drill bits I have found all seem to be for cutting tiles. Am I looking at the wrong thing or will these be OK to go through the extractor?
I will be doing this with a very old Dremel tool as I don’t think my battery drill can get up to the speed that’s recommended for these tools.
This is not something I have needed to do before and am unlikely to do again. Hence I just got a cheap set of Clarke extractors and now wish I had just got a single expensive one.
If I can get the extractor out, I will just drill the entire bolt out and run a good M8 tap through to recut the thread.

 

[Brad93]

As said, build up with tig, stick a nut on the build ip and tig that too, unscrew with a spanner

 

[Dilkris]

Hi MikeBs - got any pictures you can post?

 

[quench]

I put a large washer over broken stud/tap then nut on top of washer, especially if using a mig

 

[MikeBs]

As said, build up with tig, stick a nut on the build ip and tig that too, unscrew with a spanner

I don’t have a tig welder, only mig and not skilled enough to not make a mess of it.
The bolt is sheared in a hub carrier and holds a bracket to support a brake line.
So access is a bit tight as it all sits in a wheel arch. I don’t want to remove the hub carrier as it’s a massive job and will all need to be aligned again.
I am happy to spend a few hours with a dremel and grind it out. My worry is that I will use the wrong thing and break another tool that’s even more difficult to remove.
The diamond hole cutters all have a hex head that’s too large for my dremel, so I am now looking at the diamond grinder bits.
Am I just wasting my time with these?

 

[ukracer]

I don’t have a tig welder, only mig and not skilled enough to not make a mess of it.
The bolt is sheared in a hub carrier and holds a bracket to support a brake line.
So access is a bit tight as it all sits in a wheel arch. I don’t want to remove the hub carrier as it’s a massive job and will all need to be aligned again.
I am happy to spend a few hours with a dremel and grind it out. My worry is that I will use the wrong thing and break another tool that’s even more difficult to remove.
The diamond hole cutters all have a hex head that’s too large for my dremel, so I am now looking at the diamond grinder bits.
Am I just wasting my time with these?

Sadly in my experience yes. The welding trick is the only one that I would try but......I am.no expert.
If you could get it off and in a drill press or milling machine a carbide drill would be a great tool to use. Although I have used a high quality burr before i had carbide. However I had to helicoil the thread.

The problem you have is two fold.
Siezed bolt and stuck and snapped extractor.

 

[tom2207]

if your not great with a mig , cut a bit of copper pipe that fits in the hole to protect the sides , leave it a mm or two proud of the surface , then weld down through the center of the pipe ,, i dont do the nut thing , i do flat bar and drill a hole in it , weld it as if it was a washer , as its shallower its easier to weld , then use that bar as a spanner , give it all a tap or two on the weld , let it cool , weld the top again , let it cool a quick squirt of acf50 , and most things will turn out.

 

[JEZGUZ]

Do a search for carbide burrs with a 3mm shank, they will fit a Dremel.

 

[MikeBs]

More research and I think I am going down the carbide ball nosed burr route.
I have seen York brand for about £30 or Presto for about £15.
Since this will hopefully be a one off use does anyone have experience of either brand?

 

[Brad93]

More research and I think I am going down the carbide ball nosed burr route.
I have seen York brand for about £30 or Presto for about £15.
Since this will hopefully be a one off use does anyone have experience of either brand?

York are chinesium. won't be much better than the presto. I certainly wouldn't pay £30 for one. maybe £10-12

Pferd burrs are £30 and world class

Garryson is a more common brand over here

 

[tom2207]

York are chinesium. won't be much better than the presto. I certainly wouldn't pay £30 for one. maybe £10-12

Pferd burrs are £30 and world class

Garryson is a more common brand over here

nail on the head .

A die grinder is just a blender if you dont have good burrs.

 

[Dilkris]

Sadly in my experience yes. The welding trick is the only one that I would try but......I am.no expert.
If you could get it off and in a drill press or milling machine a carbide drill would be a great tool to use. Although I have used a high quality burr before i had carbide. However I had to helicoil the thread.

The problem you have is two fold.
Siezed bolt and stuck and snapped extractor.

The problem he has may be more than two fold - he may not have access to a fully equipped workshop.

 

[Stupoty]

I've had luck with using small grinding stones for a die grinder (pointy or cone ones mostly) running in reverse in a drill press , some things have started to un-do this way , might be enough to get the broken extractor out and go back to drilling it through as much as possible before resorting to poky things to brake bits out of the hole.

Stu

edit , for the extractor you would run it in the forward direction whoops

 

[Brad93]

I think the OP's best bet at this stage could be to call someone out who has a tig.

 

[ukracer]

The problem he has may be more than two fold - he may not have access to a fully equipped workshop.

Well yes. BUT if he is not going to be able to fix it , sadly he will end up going to a fully equipped workshop.