Snapped My Banjo

Cheers. So according to my 'research', the thread is 1/8 BSP - I don't have any left hand bits, so I'll need to get some. What would be the right size to drill this out please? Don't want to buy the wrong thing.

sp00k said:

Cheers. So according to my 'research', the thread is 1/8 BSP - I don't have any left hand bits, so I'll need to get some. What would be the right size to drill this out please? Don't want to buy the wrong thing.

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be sure to buy some elbow grease with your left hand drill bit!

if it all buggers up, just glue on a plastic elbow.. good luck

and a longe weight

You do get left hand bits. The flutes are in reverse so that when you drill in the reverse direction, the material is removed. Using a normal bit in reverse is going to force the crap into the hole, which is what I'm trying to avoid.

Demo here:

https://www.youtube.com/watch?v=FYvaPbX1sT4

I always use stillsons instead of mole grips. Hell of a lot better grip if you only have one shot at it.

I used 10" tonight on the swivel housing filler plugs which please me no end as they were corroded beyond redemption. Monday night I used 24" for holding the flange plate on the rear diff while undoing the nut. I used to do the tracking on my discovery using a pair of stillsons, a couple of concerete blocks, some string and only a bit of trial and error.

The last resort is drilling out.

sp00k said:

You do get left hand bits. The flutes are in reverse so that when you drill in the reverse direction, the material is removed. Using a normal bit in reverse is going to force the crap into the hole, which is what I'm trying to avoid.

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aye i know, but it used to be an old apprentice joke.

you can even buy elbow grease now!

If you are going to tap a 1/8 BSP thread you need to drill the hole to 8.8mm.

123-eddy09 said:

If you are going to tap a 1/8 BSP thread you need to drill the hole to 8.8mm.

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Thanks. I'm not goint to tap a thread - there is already one there, I'm just going to drill down the existing thread. As the bolt has a very thin wall, I'm hoping it will disintegrate whilst I drill and leave the thread intact.

sp00k said:

Thanks. I'm not goint to tap a thread - there is already one there, I'm just going to drill down the existing thread. As the bolt has a very thin wall, I'm hoping it will disintegrate whilst I drill and leave the thread intact.

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Probably best practice to run a tap down the thread to clean it up anyway or you may end up back in the same situation.

Jam1 said:

Probably best practice to run a tap down the thread to clean it up anyway or you may end up back in the same situation.

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We're not still talking about his helmet are we?

Jam1 said:

Probably best practice to run a tap down the thread to clean it up anyway or you may end up back in the same situation.

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Yeah, will do - if I can get the bloody bolt out without destroying everything! What I meant was, I'm not drilling a fresh hole (yet), so I won't need a bit exactly the recommended width for the tap size.

the_wolf said:

We're not still talking about his helmet are we?

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Would you recommend cutting oil with that or grease?

I'm coming around to the idea of using some sort of easy out.

I had a peek tonight with a mirror so I could see properly from an overhead view. I was going to take a pic but my battery has died. To picture the scene, there is about 4mm of the bolt protruding. About 1/4 of that has snapped off (I thought it was more).

Before the 1/4 snapped off, I thought that it had turned a little. Now that the 1/4 has gone, it's impossible to get any sort of grip on it.

I'm coming around to the idea of trying an easy out. Here's my logic - I think the bolt had been overtightened which was why it snapped when I tried to free it. If it had been a normal bolt, and not a hollow one, I don't think it would not have snapped. Can anyone recommend a brand or are they much the same?

I've got a set of Sealey easy outs in my tool box but I've never used them so can't say if they're any good. If you try an easy out I'd recommend to hit the stub of the banjo bolt and the surrounding area with a hammer to put some shock through it.

Just another idea to throw into the mix. You could drill the hole out part of the way through say with an 8mm bit. Then us a chisel around the bolt to collapse it in then try a small pair of mole grips. I've done this on exhaust manifold threads before.

123-eddy09 said:

I've got a set of Sealey easy outs in my tool box but I've never used them so can't say if they're any good. If you try an easy out I'd recommend to hit the stub of the banjo bolt and the surrounding area with a hammer to put some shock through it.

Just another idea to throw into the mix. You could drill the hole out part of the way through say with an 8mm bit. Then us a chisel around the bolt to collapse it in then try a small pair of mole grips. I've done this on exhaust manifold threads before.

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I can't drill the top of the bolt as part of it's side has broken off, so that about 3/4 remains. To drill it, I would have to cut the remainder of the bolt off to get it level.

A question I meant to ask is how long are the bolts? I was going to take the front one out to check, then I though - nah, I'll leave it

Picked up a clark screw extactor kit this moning on the way to work, so I'll have a go with it tomorrow. Any tips on how much resistance I should feel? I presume it should feel like when you're tapping a hole. My plan is to not try any drilling and just go with a size that will fit down the existing bolt.

sp00k said:

Picked up a clark screw extactor kit this moning on the way to work, so I'll have a go with it tomorrow. Any tips on how much resistance I should feel? I presume it should feel like when you're tapping a hole. My plan is to not try any drilling and just go with a size that will fit down the existing bolt.

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I have some easy outs. They just tighten in, go slowly, then when they are tighter than the offending part will start to wind it out. Go by hand and judge it, as if you snap the easy out they are almost impossible to drill.

The bolts aren't to long, maybe the threaded bit is 10mm maybe? Want me to whip one of mine out and measure?

Hopefully if you felt it move a bit it should wind out ok, shock and penetrating oil the #### out of it before hand though

Be really careful.
If you think your stuck now try getting a snapped easy out out.
They also spread what ever your trying to get out,
If its not moving easily dont force it.
Id do whats suggested above, shock it and id try warming it with a blow torch first.

flat said:

I have some easy outs. They just tighten in, go slowly, then when they are tighter than the offending part will start to wind it out. Go by hand and judge it, as if you snap the easy out they are almost impossible to drill.

The bolts aren't to long, maybe the threaded bit is 10mm maybe? Want me to whip one of mine out and measure?

Hopefully if you felt it move a bit it should wind out ok, shock and penetrating oil the #### out of it before hand though

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Thanks for the advice. I will go with your estimate on length, so there is probably only about 5mm left.