Broken Stud & Bolt Removal Techniques

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Fred
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Broken Stud & Bolt Removal Techniques

Post by Fred »

Following on from the highly successful locking washers and idle valves threads, I present a couple of new threads, and this is one.

How do you get those bolts and studs out when it's looking dire?

I saw a technique on another forum the other day:
  • Put a nut over the hole and plug weld it, then attempt to remove.
Others in the thread met with mixed success. Which led to the following suggestion:
  • Put a washer over the hole and weld all the way around the inner edge, then weld a nut to the washer, then try to remove.
Those who had previously failed met with success using this method.

Noticed a possible exhaust leak on a friend's car today in a photo I'd taken, and decided to throw this out there to all the bright engineering minds, and see what they come up with. Nothing's too obvious. So I'll go in again with a third:
  • Drill out the centre carefully so as not to damage the threads, then poke and pray and hope for the best.
What have you got? :-D

Fred.
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Corbon
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Re: Broken Stud & Bolt Removal Techniques

Post by Corbon »

Things people tried to teach me as an apprentice before I became a desk jockey:
  • Drill out the top thread of the hole:
    This tends to get damaged by the shoulder of the stud when it is tightened down. If you remove them then it takes less torque to turn the stud and is less likely to strip your easy-out hole or snap off your welded nut as you lie contorted on top of a V6 watching the one hand you can get down there with a mirror.
  • Drill dead centre:
    Takes less torque for the easy-out to turn the stud as per above.
    If you end up having to drill the stud right out you are less likely to cut into the threads in the hole and less likely to have to helicoil/recoil and more likely to be able to remove the remains of the stud threads in one piece without having to try pick out small bits and cause damage.
  • Drill for the smallest easy-out that will be able to turn the stud:
    When you tap in the easy-out it applies force radially outwards on the stud which tries to bind the threads tighter in the hole. If you use the smallest possible size the remains of the stud are more rigid and this effect is reduced.
  • If the threads are corroded then all bets are off:
    If things are really crusty sometimes it's faster to just drill the whole lot out carefully and helicoil the hole rather than mucking around and wasting time and easy-outs.
Turns out these are all for drilling and using an easy-out type tool. Hopefully useful.
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Fred
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Re: Broken Stud & Bolt Removal Techniques

Post by Fred »

Photo of those things for reference:

Image
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Corbon
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Re: Broken Stud & Bolt Removal Techniques

Post by Corbon »

I've had the most luck with the straight variety.
Straight Fluted Screw Extractor.jpg
The parallel/non-tapered ones seem to work the best but you need to drill the hole well for the size of the minor diameter.
Parallel Fluted Screw Extractor.jpg
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Fred
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Re: Broken Stud & Bolt Removal Techniques

Post by Fred »

Great stuff! I'd never even heard of or seen those types! Keen to own in future, though! :-D
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ivan141
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Re: Broken Stud & Bolt Removal Techniques

Post by ivan141 »

I have never in my life used one of those threaded easy outs with success. They have a very small area that they apply load on, and the smaller ones will snap around that area if your bolt is stuck enough. Drilling the top few threads out might help out some, will try that sometime.
Best bet is always to weld something onto the broken stud when possible.
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Re: Strut Braces - post winners, and failures

Post by ToxicGumbo »

Here are some fairly decent tools I have. All have their place for both studs and bolts (not necessarily limited to either). There's a lot of debate online about the pros and cons of each of these, but people have different experiences based on what they're trying to remove along with the context and work conditions.
If exposed, it's also easy to Dremel a slot into the top of a cracked stud and use a flathead to turn it out. Additionally, an exposed stud can also be flattened on the ends for better grip or one can use some vamp channel lock pliers along with PB (Blaster) or WD-40.
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Re: Strut Braces - post winners, and failures

Post by Fred »

As evidenced by the post topics, I was forced to perform moderator duties on you, Jeff. Not quite sure how you managed to post this in the strut brace thread, but I'll forgive you :-D

I can see some use in the first two for mangled heads that are in awkward spots. I tend to use vice grips to turn those when they're more exposed. Welding is another easy option if there's lots of head left and nothing flammable nearby.

That last one is pretty cool, similar in mechanism to one of my oil filter removers (I feel another thread coming on, but another day).
ToxicGumbo wrote:If exposed, it's also easy to Dremel a slot into the top of a cracked stud and use a flathead to turn it out.
The assumption for me is that it broke for a reason: It was f***ing tight! :-) I have used the above many times for things like steering column bolts, but in combination with an impact driver so as not to risk stripping out the slot. Works well :-)
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