Equipment to remove broken studs

[bayzoo]

Hi,

I’d like to learn some of the skills needed to remove broken studs (aside from welding). I have a small bracket that came with a second hand rear subframe that has a broken stud so I thought I could practise with this.

So to drill this out I believe I’d need:

Tap (and die) set
Metal drill bits (left hand as well?)
Lubricant

I already have a Milwaukee M18 combi drill and a workbench with a vice.

Can you please recommend good products for the above and for anything else I’ve missed?

Thanks.

[Boosted LS1]

If the stud's proud there are a number of extractor types that can grip around it. A good whack can help break any corrosion around the threads.

[springfan62]

https://www.screwfix.com/p/hilka-pro-craft-damaged...

[V8covin]

Drilling it out would be a last resort.
Something as simple as some heat and mole grips may get it out.Have you got a gas torch ?

[steveo3002]

id be asking around if anyone weld put a dab of weld on it for a bit of beer money , almost always gets them out with no fuss in minutes

[bayzoo]

Thanks all - didn’t expect this many replies so soon. I should have elaborated more in my original post. The bracket I have is scrap, I can get a replacement easily; it was more for practise as I have a small M6 bolt that broke in an area of limited access on my car.

I’ve seen these extractors but they all get poor reviews so I never know which to buy. Is this because people use them wrong?

What was odd is that I managed to get it turning but it then snapped, so there is a small piece sitting proud. How about I cut a groove in with a Dremel and use an impact driver? I think I can get a flexi shaft with a cutting wheel in there.

[paintman]

Local engineering firm used one of this type to remove a sheared bolt which had left a small sticking out bit from a V8 cylinder head for me. Plus heat.
https://ridgidtoolshop.co.uk/general-purpose-tools...
Straight hole drilled using the appropriate guide to keep centre, then straight walled fluted extractor driven in followed by unscrewing the remains.

I've removed a lot of broken stuff by using a mig to weld a nut or washer followed by nut but this one I wasn't inclined to have a go as if it failed I don't have the tools required to accurately drill it out - they're an engine reconditioning specialist & do & easier if I hadn't mucked about with it.

The problem with the carrot shaped left hand threaded type is that they have a nasty tendency for the end to shear off in the hole you've drilled leaving a nice bit of hardened steel well & truly stuck in the hole.

If your bolt has already sheared it's unlikely cutting a screwdriver slot in it will work although if you really do want to go that way then plenty of heat & working the remains in & out MIGHT work possibly accompanied by liberal application of something like Loctite's 'Freeze and release'.
Bear in mind that you can sometimes get quite a lot of apparent turning on a seized bolt before it shears. It isn't actually turning in the hole it's just the deformation of the shank before it reaches the point where it shears.

Edited by paintman on Monday 3rd May 10:23

[finishing touch]

As I have every sort of welder you can think of choice1 would be weld a size bigger nut over the protruding remaining part of the stud. M8 over an M6 for example.


Choice 2 would be to drill it out using the tapping size drill for that particular thread. Sometimes I make a drill guide to ensure I drill dead centre.

"
"
"
"
"

Choice 957 would be to use one of those evil extractor things, but only because there isn't a choice 958.

[steveo3002]

you want top quality extractors ...ebay cheapies will snap off then you have the problem that it too hard to drill /remove

drill it /re tap or helicoil

[donkmeister]

paintman said:

Bear in mind that you can sometimes get quite a lot of apparent turning on a seized bolt before it shears. It isn't actually turning in the hole it's just the deformation of the shank before it reaches the point where it shears.

I can vouch for this having once twisted a Rolls Royce head stud (interference thread, with the upper few inches of the hole being unthreaded, all with 50 years of gunge holding it in) through about 10 full rotations before it sheared. I was giving it some with a 1m breaker bar, and was lucky to remain upright!

OP, there are electric induction heaters that some swear by for thermally shocking tight fasteners... They are expensive though (all the ones I've seen cost hundreds). Blowtorches are of course cheaper but more limited in their use in automotive situations both due to size and due to the inherent risks of a naked flame on something containing and coated with inflammable substances (I'd never want to use one anywhere near fuel lines, or on anything caked with grease).

[steveo3002]

if youre planning to be a car tinkerer , you can find a good used mig welder for £120 upwards , theyre very handy to have and turn jobs like broken studs into nothing

by the time youve bought a couple of cans of magic oil and some extractors that will break off , youre half way to a welder

[bayzoo]

steveo3002 said:

if youre planning to be a car tinkerer , you can find a good used mig welder for £120 upwards , theyre very handy to have and turn jobs like broken studs into nothing

by the time youve bought a couple of cans of magic oil and some extractors that will break off , youre half way to a welder

Interesting - would I need any proper training or can you ‘learn by doing and YouTube”?

I’m hoping to connect with other car tinkerers up here near Edinburgh once all of the restrictions have eased.

[steveo3002]

can self learn enough to get by , practice makes perfect and all that

plenty of forums for help

[Krikkit]

You could also try seeing if your local technical college has a course for it - I was lucky living near Myerscough when I wanted to learn to weld, did a weekend course over 5 or 6 weeks and learned to gas torch (weld and cut), stick, MIG and badly TIG weld, plasma cutting, etc etc all in a structured course.

[bimsb6]

Go on youtube , numerous videos on how to remove broken studs .

[rxe]

As others have said:

- Don’t break it in the first place - use heat early, use penetrating fluid as soon as it moves, and work it in and to clear the debris and spread the penetrating fluid. 90% of the time I am faced with a snapped stud is because I have been ham-fisted. The other 10% is where it is impossible to use heat and penetrant.

- If anything is protruding, heat and penetrant, get a grip and wind it out.

- Just welding a nut on it is the gold standard. Welding is easy, buy a MIG, a decent one, not a flux cored piece of crap, and learn to use it. You don;t need to go to school for MIG, it’s like a glue gun that shoots metal. Once you have the basics down on scrap new steel, learn on thin/corroded/awkward stuff and you’ll be fine.

- Extractors - if an extractor is the answer, you’re asking the wrong question.

[gnc]

i was a bit worried about the studs on my stag exhaust manifold, so ive ordered a cheap magnetic induction heater to play with.

[bayzoo]

rxe said:

As others have said:

- Don’t break it in the first place - use heat early, use penetrating fluid as soon as it moves, and work it in and to clear the debris and spread the penetrating fluid. 90% of the time I am faced with a snapped stud is because I have been ham-fisted. The other 10% is where it is impossible to use heat and penetrant.

- If anything is protruding, heat and penetrant, get a grip and wind it out.

- Just welding a nut on it is the gold standard. Welding is easy, buy a MIG, a decent one, not a flux cored piece of crap, and learn to use it. You don;t need to go to school for MIG, it’s like a glue gun that shoots metal. Once you have the basics down on scrap new steel, learn on thin/corroded/awkward stuff and you’ll be fine.

- Extractors - if an extractor is the answer, you’re asking the wrong question.

Thanks, that's good advice - I've decided I need to learn to weld; I've connected with a couple of experts locally on another forum. I also need to buy a new house with more space, hopefully that will happen soon.

[bayzoo]

Thanks all - I’ve decided to learn how to weld as it appears I’ll be encountering more of these situations as I progress my hobby. Have made contact with someone locally on a welding forum who is kindly going to introduce me to welding before take the plunge and buy my own set up.

Edited by bayzoo on Monday 10th May 13:51

[markcoznottz]

donkmeister said:

paintman said:

Bear in mind that you can sometimes get quite a lot of apparent turning on a seized bolt before it shears. It isn't actually turning in the hole it's just the deformation of the shank before it reaches the point where it shears.

I can vouch for this having once twisted a Rolls Royce head stud (interference thread, with the upper few inches of the hole being unthreaded, all with 50 years of gunge holding it in) through about 10 full rotations before it sheared. I was giving it some with a 1m breaker bar, and was lucky to remain upright!

OP, there are electric induction heaters that some swear by for thermally shocking tight fasteners... They are expensive though (all the ones I've seen cost hundreds). Blowtorches are of course cheaper but more limited in their use in automotive situations both due to size and due to the inherent risks of a naked flame on something containing and coated with inflammable substances (I'd never want to use one anywhere near fuel lines, or on anything caked with grease).

The induction tools are loads cheaper now, see eBay. I never understand why lads spend thousands on snap on/Mac tat, then won’t buy an induction tool as they are ‘too expensive’. They are the best thing in 20 years in the trade, the other being those 1mm cutting discs. If you can get easy safe access, a mapp gas torch can perform the same trick. Same process, heat till nut/ stud is dull cherry colour, douse with water, no sweat, no noise, no hammering, just make the tools do the work. Even If the stud has hardly any showing, you can weld a nut on then use the heat method as well.