Here is a final nuclear option before taking it to a machine shop. Get the set of Bosch GT2000 glass cutting carbide bits as shown below. They will penetrate hard metals better than diamond tip bits. I broke off a hardened easy-out extractor in a Jeep exhaust manifold stud last year and nothing worked...until I read about the Bosch GT2000 bits. Use cutting oil and don't force the bit as excessive heat buildup will dull the cutting edges.
Broken exhaust stud removal
- Thread starter JHZR2
- Start date
I saying here that you still need to weld a nut on each one. If you break a carbide easy out in the one thats almost flush, you will have a much bigger problem.
I'd clean the oil out with carb cleaner really well, let it dry and weld a nut on. This might be a good time to take it to the machine shop, as they can do this.
JHZR2
Staff member
I don’t know that I’ll need helicoils. The two studs that came out left good threads. Time will tell.
Time sert or helicoil if needed.
Hoping neither, just chase and replace.
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JHZR2
Staff member
Part of the intention with all this is to learn and have skills. It’s not a hobby otherwise.
Sometimes things are over my head. I will go to a shop for that.
Believe it or not, asking around, most shops can’t even recommend a machine shop anymore. The one recommended is a good 30-40 minutes away.
I would like to learn to weld and do things like this, but the sunk cost is high, time commitment kind of as well.
I need to find a community college or something to learn at.
And then a welder which to me is a $400+ shelf ornament more often than not. And then bottles of gas too. It’s a lot of stuff to have around… not that I don’t have a lot of other marginally useful stuff!
But I do find the benefit to being able to weld about once every year or two…
I get it, thats how i got into doing things. I bought a welder a lincolin 3200hd and watched videos, read and practiced on scrap steel. I'm not a super experienced welder, but i have done several things that i could not have repaired with out one. A community college class would be great, but as intelligent as you are, you don't have to go that route. The project you have now is perfect for this.
I started with flux core, and later used gas. 1 bottle of gas like mine will last 10 years or more, on small jobs.
You might look around for good used welders. OR bite the bullet for a new one. I'd get one that you can add gas to later, so you don't have to buy another unit. My welder is so out of date and old but it is perfect for small jobs where i can run it in 110v , even from my generator.
Even the HF welders are probably more advanced and easier to learn on than mine.
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CleanSump
Site Donor 2026
Welding iron properly will require heating the manifold to a good 500F or so.
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He only needs to weld a nut onto a stainless bolt. Not weld the manifold.
But yes cast iron needs to be heated , and use the right wire. I've welded some cast by heating it and using stainless mig wire, which is the wrong wire , but was successful.
JHZR2
Staff member
I think the key is to NOT weld to the cast iron.
I’d want to weld a steel (?) nut to a stainless stud remnant.
I’ve seen some videos where for recessed broken studs, they put a short length of copper tubing in the hole to prevent any welding to the parent material.
CleanSump
Site Donor 2026
Ahh so! I was thinking of building up the flange if he drills it off center or way big, A nut on the stud, yeah, no big deal.
Try the carbide, maybe not necessarily harder, but tougher. I think the weakness of the diamond tips, most are so cheaply made. I would just keep at it though with different sizes and shapes.
I would try this or the like, next, first use the size that almost but doesn't quite fit. I would do it in the drill press if possible: https://www.amazon.com/VALYRIANTOOL-Cobalt-Removing-Broken-Reverse/dp/B0FFCSQ2YQ
https://www.amazon.com/s?k=reverse+drill+bits&crid=1UZPPQ3ME0F29&sprefix=reverse+drill+,aps,202&ref=nb_sb_ss_p13n-expert-pd-ops-ranker_ci_hl-bn-left_1_14
I would try this or the like, next, first use the size that almost but doesn't quite fit. I would do it in the drill press if possible: https://www.amazon.com/VALYRIANTOOL-Cobalt-Removing-Broken-Reverse/dp/B0FFCSQ2YQ
https://www.amazon.com/s?k=reverse+drill+bits&crid=1UZPPQ3ME0F29&sprefix=reverse+drill+,aps,202&ref=nb_sb_ss_p13n-expert-pd-ops-ranker_ci_hl-bn-left_1_14
Drill a bit larger.
Keep the bit CENTERED.
Then drill a bit larger.
Keep it centered.
Take out 80% or more of the stud material until you just kiss the threads of the manifold and there is almost nothing left of the stud.
Tiny chisel and work the remaining material out.
Chase the threads.
OR
Pay a machine shop to weld and remove this.
Keep the bit CENTERED.
Then drill a bit larger.
Keep it centered.
Take out 80% or more of the stud material until you just kiss the threads of the manifold and there is almost nothing left of the stud.
Tiny chisel and work the remaining material out.
Chase the threads.
OR
Pay a machine shop to weld and remove this.
Agree but left twist bits and drill press.
You need to drill closer to the size of the stud in increments until you are close to the original threads in the manifold then try an easy out, the bigger the easy out the better but be careful not to snap it off. Use a tap wrench as not to put too much force on it.
The stud that is blind just measure the thickness of the manifold where the one that goes through is then add the protrusion eg manifold 13mm thick stud left sticking up 10mm = approx 23mm you need to go to get to the bottom of the stud go 21mm and call it good.
The stud that is blind just measure the thickness of the manifold where the one that goes through is then add the protrusion eg manifold 13mm thick stud left sticking up 10mm = approx 23mm you need to go to get to the bottom of the stud go 21mm and call it good.
First is what I always do if it's feasible to do so.
I have had to use very tiny carbide tips on a dremel with cutting fluid and going very slowly on some stuff and have pulled it off. Must be very careful and patient though.
JHZR2
Staff member
Well I’m officially, truly, defeated.
Drilled through all the way with left hand bits. Nothing.
Used every extractor I have. Everything slipped.
I guess I’ll just drill with my 6.8mm bit and re-tap whatever conglomeration of metal is permanently fused in there??
I think I’ve busted all my extractors.
Yeah, I should have spent $400+ on a welder. But I’m not sure after all this and how hard this is stuck in there, that it would have helped.
Welders I’ve contacted wanted $100 to weld two nuts. With no likelihood of quality or success.
I’m sure a machine shop would want $250 to do it.
The recommended shop was 45 minutes away. Given my work and kid schedule the next chance I had to do something like that might have been the Fourth of July. I’m that busy.
Of course with how all this is going it’s likely that I’ll have issues with tappin that new thread too. Not sure now to deal with that. If I could barely drill these things with cobalt bits, am I really going to be more successful tapping new threads into some odd mixture of this stainless and cast iron??!?
What I do know is that I’m unlikely to ever try to do something like this ever again. What a mess and waste of time. The useful things I could have gotten done on just spent with my kids. Ugh.
Drilled through all the way with left hand bits. Nothing.
Used every extractor I have. Everything slipped.
I guess I’ll just drill with my 6.8mm bit and re-tap whatever conglomeration of metal is permanently fused in there??
I think I’ve busted all my extractors.
Yeah, I should have spent $400+ on a welder. But I’m not sure after all this and how hard this is stuck in there, that it would have helped.
Welders I’ve contacted wanted $100 to weld two nuts. With no likelihood of quality or success.
I’m sure a machine shop would want $250 to do it.
The recommended shop was 45 minutes away. Given my work and kid schedule the next chance I had to do something like that might have been the Fourth of July. I’m that busy.
Of course with how all this is going it’s likely that I’ll have issues with tappin that new thread too. Not sure now to deal with that. If I could barely drill these things with cobalt bits, am I really going to be more successful tapping new threads into some odd mixture of this stainless and cast iron??!?
What I do know is that I’m unlikely to ever try to do something like this ever again. What a mess and waste of time. The useful things I could have gotten done on just spent with my kids. Ugh.
What size threads again? M8x1.0 or 1.25? Drill with 7mm or 6.8 mm bit and tap.
I think two nuts on the stud would have just broken the stud frankly. Relax, man you are OK
I think two nuts on the stud would have just broken the stud frankly. Relax, man you are OK
Drill it out and install a helicoil. Same size as the OE studs. Install new studs.
You can do that with the blind hole. Keep it blind.
No need to go through.
Then, throw those “easy outs” in the trash. The only thing they do, as you’ve discovered, is chew up what’s left.
They don’t get the broken part out, ever.
You can do that with the blind hole. Keep it blind.
No need to go through.
Then, throw those “easy outs” in the trash. The only thing they do, as you’ve discovered, is chew up what’s left.
They don’t get the broken part out, ever.
JHZR2
Staff member
M8x1.25
Two nuts on the stud did nothing but slip. I could never get it cinched up enough. No matter what I did. They probably would have galled or snapped the stud at the nut to nut interface first.
Maybe I should have heated and quenched more. Not sure it would have helped.
Well one extractor got a broken stud on the head out. But yeah, not any help. They did take a lot of torque. I had a lot of force on them.
Helicoil or time sert?
Helicoil.
CleanSump
Site Donor 2026
Helicoil. Generic kits with a tool are cheap on Amazon and they work just fine.
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