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Broken HSS drill bit in broken Stud. Assistance would be great!

Kiwi Tussock

Active Member
Joined
May 27, 2011
Messages
26
Location
New Zealand
Seasons best wishes to all. Hope its been an enjoyable one and alls warm and safe for you all. Over here in New Zealand (it's mid summer 27 degrees C here (approx 80F)) we go to the beach or lakes for most of the next month or two. Bit different for a Christmas for you Northern hemisphere bods ay! :cool2

The problem I have, is with an old single banger diesel (UK Bamford) I have and which I have a broken stud in the crank case and have started drilling it out after 1st centre punching it. The pilot holes drill bit was HSS of only 3mm in size but when it got to the end of the 3/8 stud, it grabbed and I must have not been ready for it and it either must have moved the drill & bent it or for some reason, it broke.
The stud broke below the surface line.

Does anyone got a bright idea how I might get either this drill bit out or the whole 3/8 stud out?
I'd rather not use heat because of the paint work but there may be no other way.

I have considered either carefully drilling a number of other 3mm or 2.5mm holes around the centre drill bit but it scares me that I might break them also and really stuff it up even more! Also considered is getting the Dremel out and slowly grinding away at it. I have an "Ezy-out" but the broken end of the dill bit is too close to the surface to allow it to get a decent bite at the seized stud.

Any suggestions would be greatly appreciated.
 

GOINGBROKE

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Apr 28, 2007
Messages
85
Location
WYOMING
Occupation
Diesel shop owner - truck, farm and heavy equipmen
Die grinder or dremel tool and a lot of Patience
 

mitch504

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Feb 27, 2010
Messages
5,776
Location
Andrews SC
I know you said you don't want to use heat, but I know people who can weld onto the broken stud and bring it out. You may have to use heat, if the stud is seized in the hole, anyway.

If you go this way, look for a good welder who doesn't brag, the ones who think you should be able to do this miracle if you'd try are usually best. :D

Good Luck, and my sympathies,
Mitch
 

Impact

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Location
Kentucky
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Owner
I know you said you don't want to use heat, but I know people who can weld onto the broken stud and bring it out. You may have to use heat, if the stud is seized in the hole, anyway.

If you go this way, look for a good welder who doesn't brag, the ones who think you should be able to do this miracle if you'd try are usually best. :D

Good Luck, and my sympathies,
Mitch

I second this aproach. I've used it many many times with great results. The direct heat on the stud seems to loosen it right up. Get a welder who's done it before. There's a right time to extract the stud after welding. As soon as it's cooled down enough to hold. If it cools too much, it could be tighter than before.
 

rare ss

Senior Member
Joined
Apr 1, 2011
Messages
460
Location
Western Australia
tryied using a strong magnet to get it out? or a colbolt drill bit may chew the HSS one

either that you a small point burr and die-grinder to enlarge the hole bit by bit, i did the same thing once with a colbolt drill bit.. worst thing was it had broken off with 1mm hanging out so it wasnt enough to grip but enough to give you some false hope on an easy fix, ended up drilling another hole next to it and using that hole and a burr was enough to make a large hole central enough to run a larger drill down it but a 3/8 stud doesnt give you alot to play with, I've used to welding method afew times if theres enough stud hanging out to screw a nut on afew threads and welding that to the stud but if the stud is flush or broken below the head I wouldnt recommend it for your first attempt at the job

LH colbolt drill bits are the best for broken exhaust studs IMO as they generally break due to the expansion of the manifold shearing the stud hence the stud into the head isnt as tight when compared with a heavy corroaded bolt which has snapped off
 

Kiwi Tussock

Active Member
Joined
May 27, 2011
Messages
26
Location
New Zealand
Thanks to Carlsharp and Rare SS for their ideas. The wonderful web site of the magnificent work of web site "Mikesworkshop" that Carl suggested I take a look at, has some beautifully made products. ALMOST as beautiful as a naked woman but we wont go there ay. Well, at least some of them.
And Rare SS across the ditch, funny you mentioned Cobolt bits. I ordered a Snap-On LH Cobolt bit set earlier today. The Dremel kit I have isn't that flash & need a lot more bits to attack a job like this.
I havent tried a magnet as I have nothing around that is likely to work. Also its below the surface of the block so it wouldn't work on this job. Same for the welding idea as it would fuse to the cast iron block. I really would like this sorted this year cause I really don't want a xxxxx of a job to start the New Year off on but that's where it's heading as the New Year is gonna beat the arrival of the Cobolt bits. Bugger!
I did wonder if I would need to just move on and start a new hole and tap it out but that would also mean changing the mounting plate to the plate that fits over the orifice. That bit scares me somewhat as it would be into the water jacket which I don't really want to test my luck on.
Anyway, may be some bright cookie will come along as my fairy god father and tell me something that might work easy as.
Thanks
 

Scrub Puller

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Mar 29, 2009
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3,481
Location
Gladstone Queensland Australia
Yair...Kiwi. As some of the other posters have mentioned it MAY be possible to get this out with a welder. Provided the stud is broken close to the face a good operator on a TIG would be able to centre a heavy eight mm flat washer on the broken stud and get a good weld through the centre.

Its just a matter then of TIGing (say) a ten or twelve mm nut onto the washer and let the whole thing cool down...I'd be surprised if you couldn't then back it out with an eight inch shifter.

I realise of course that A TIG may not be available but the light weight inverter jobs are pretty common these days and it may pay to ask around.

Best of luck and let us all know how you went.

Cheers
 

mitch504

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Messages
5,776
Location
Andrews SC
Not to be argumentative, because I know it seems hard to believe, but the welding approach is very doable. I have seen it done on a broken 3/8 bolt an inch below the surface. I would not reccomend it for a beginning welder, but there are people who can build up from the broken piece, out of the hole, weld a nut on, and unscrew it. I have done this myself several times on 5/8 and 3/4 wheel studs, but it takes a good welder to do a 3/8 below the surface. The block being cast iron actually makes it easier, since you are less likely to damage it than if the hole was in steel.

There are special welding rods sold for the purpose, but I have never actually seen those.

Google "welding rod bolt removal", you'll see a lot of explanations and instructions.

http://www.google.com/search?source...*:IE-Address&ie=UTF-8&oe=UTF-8&rlz=1I7ACGW_en
 
Last edited:

Impact

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517
Location
Kentucky
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Owner
Not to be argumentative, because I know it seems hard to believe, but the welding approach is very doable. I have seen it done on a broken 3/8 bolt an inch below the surface. I would not reccomend it for a beginning welder, but there are people who can build up from the broken piece, out of the hole, weld a nut on, and unscrew it. I have done this myself several times on 5/8 and 3/4 wheel studs, but it takes a good welder to do a 3/8 below the surface. The block being cast iron actually makes it easier, since you are less likely to damage it than if the hole was in steel.

There are special welding rods sold for the purpose, but I have never actually seen those.

Google "welding rod bolt removal", you'll see a lot of explanations and instructions.

http://www.google.com/search?source...*:IE-Address&ie=UTF-8&oe=UTF-8&rlz=1I7ACGW_en

I'm with you 100%. Seen it done. Done it. It works. Like you say, especially in a cast block. No one ever seems to believe it, so, I let it go, and don't argue. Bottom line...It works.
 

RayF

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Jul 8, 2011
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640
Location
Perth Western australia
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lineborer/welder
If you were closer I could spark erode it out for you:) Do a google on "Artu" drill bits. They are tungsten carbide and will cut just about anything.They will drill what a cobalt won't mark;) You need a decent drill press to set it up in.
 

qball

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Dec 30, 2007
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il
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local 150 operator
i took a class our training site put on and we were told to use stainless steel rod. i forget the number, but it wont leave a mess.
 

rare ss

Senior Member
Joined
Apr 1, 2011
Messages
460
Location
Western Australia
Not to be argumentative, because I know it seems hard to believe, but the welding approach is very doable. I have seen it done on a broken 3/8 bolt an inch below the surface. I would not reccomend it for a beginning welder, but there are people who can build up from the broken piece, out of the hole, weld a nut on, and unscrew it. I have done this myself several times on 5/8 and 3/4 wheel studs, but it takes a good welder to do a 3/8 below the surface. The block being cast iron actually makes it easier, since you are less likely to damage it than if the hole was in steel.

There are special welding rods sold for the purpose, but I have never actually seen those.

Google "welding rod bolt removal", you'll see a lot of explanations and instructions.

http://www.google.com/search?source...*:IE-Address&ie=UTF-8&oe=UTF-8&rlz=1I7ACGW_en

I'm with you 100%. Seen it done. Done it. It works. Like you say, especially in a cast block. No one ever seems to believe it, so, I let it go, and don't argue. Bottom line...It works.

getting a broken bolt/stud out is alot like "making love", theres alot of differant ways to doing it, it all leads to the same result.. just gotta do what you feel comfortable doing :)

I've seen bad attempts by semi-skilled people getting the heat out before trying to drill it first, I've also worked on alot of gear which had spent time cleaning up spoils around a nickel plant and tailings dams which you have got no choise but to spark erode out seized and broken bolts but its all about information sharing at the end of the day, not about being right or wrong
 

willie59

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Knoxville TN
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Service Manager
I have to comment. We know little about the busted stud, other than it's a 3/8 size stud, broken below the hole entry, and presently have a broken HSS 3 mm bit stuck in it, and that it's busted in a crankcase. Aside from that, what made the stud break in the first place? Were you trying to screw it out, it seized up, and snapped off? If that's the case, you're going to have fun removing it no matter what you do, and it would likely require heat, from either a torch or from using stud puller welding rods which build a layer of slag that doesn't mess up threads in hole.

If these are not feasible, as Ray F stated, a tungsten carbide bit will drill through stud and broken drill bit, but it requires lots of down pressure and slow rpm. If you can drill through the stud and broke bit with another bit, dead center, then work your way up to a proper size for 3/8" tap, which is a 5/16" bit for 3/8-16. Then you can use a 3/8 tap to start into existing threads, since it's broke off below hole entrance, and let the tap chew our remaining bolt in block threads.
 

OldandWorn

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Nov 12, 2009
Messages
908
Location
Md/Pa
Usually when a drill breaks while exiting a hole it’s not stuck too badly, meaning if you can twist it slightly counterclockwise it may be easy to pull out. Without a picture or knowing if you can work in a comfortable position I would suggest trying to remove the drill bit and at least get back to square one. With patience and a MIG set up just right I would build up the end of the bit with a series of very quick tacks, or balls. If you can work vertically a gas torch would do the trick as well. Assuming the stud is frozen in place I would continue with a drill and tap routine if your hole is well centered.
 

Kiwi Tussock

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May 27, 2011
Messages
26
Location
New Zealand
Hi Guys. Thanks so much for the suggestions and indeed the time you have taken to ponder on my problem. I hope Santa left you a beer or two when he left a few days back.

Just to clarify a bit more. The stud held on a water manifold and as it passed through the manifold, the design of the manifold allowed the stud to be exposed to the cooling water. Obviously no soluble oil or anti freeze has been used for a LONG time. If ever.
The two studs holding the manifold to the crankcase were both badly rusted. Infact one of the studs (the one I got out) was only half the diameter. I know I was lucky to get that one out.

The depth of the hole is about 13mm (half an inch) The casting is about 19mm (3/4 "). The one I got out was in a blind hole but when I put my little pinky in to feel inside the water jacket, I think I can feel the end of the stud!?!? Either that or it's a pock in the cast iron casting of about the same size.

The suggestion of the Eroder was a brilliant idea but this motor sure as heck ain't able to be lifted onto a drill presses table! It's a very rounded crankcase with a couple of large flywheels and all up, weighs 600kg dry.(1320 lbs)
I understand that the Eroder also works on gravity so that would mean it would need to be on its side, which is not a major problem but because of the shape of the crankcase, i.e. being rounded, a fairly exact frame would have to be constructed.
I haven't seen an eroder working but with other work I do, iI can se GREAT possibilities with other tasks I do and likely to increase my work hours at. (repairing & rebuilding wood & coal ranges)

Welding? Well, a cobber is far better at it and WAY more experienced than me. After reading up on some web sites last night, I see that it is a very common method of getting sunken and seized, broken studs/bolts out. While in town today, I tried to find a welding shop open to buy some 7818 rods but here in NZ, we pretty shut up shop between Christmas & New Year and all the places I went to were shut up tight. The miserable sods were probably all out havin' a good day & having a barbie at the beach or at one of the lake!

I actually asked all the serious tool shops/suppliers in whats left of the city (since the earthquakes & the ones who were working) if the USA made Artu bits were available here. They had never heard of them. P&N who are the main manufacturers & suppliers here in NZ & made reasonably locally, had every thing except the Carbide tipped Cobalt LH twist. So after reading all the responses to the question I put out there on this site, I went for what I think was possibly going to be the 2nd best, the "Snap-On" Kit which has the Extractors and LH twist Cobalt bits in it and if the welding build up doesn't work, I thought I'll attack it with that extractor kit.

There is no room for a further hole in the manifold so it's a must succeed job.


I certainly do appreciate the wisdom and the amount of it out there in Cyber land. The headache has been and will be a rather steep learning curve for me, and a problem to the degree of which I have not come across before.

I'll come back with tomorrows "SUCCESSES" once I have finished Yahooing. :D
Thanks guys
 

heavylift

Senior Member
Joined
Sep 5, 2009
Messages
1,046
Location
KS
Left hand bits will sometimes back the broken bolt out. I would let it soak in a good penetrating oil for a day or two.

Most people will think you are giving them a load of BS when you ask for a left hand bit, so go with a part number.
 

RayF

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Jul 8, 2011
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640
Location
Perth Western australia
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lineborer/welder
If you can establish that the stud goes right through the casting the job gets a lot easier.If it was in my shop I would consider getting a cutting torch with a very clean or new tip and simply blow right through it. A skilled man (or woman) can take the stud right out even cleaning the treads out.Even if the thread is damaged beyond repair it may well be possible to drill it oversize and tap it to say 5/8 and machine up a sleeve to go in there.You could make it a blind ended sleeve if you want. Other wise just helicoil it.:) We do similar jobs often.
 

alrman

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QLD Australia
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Diesel Fitter;Small Business Owner;Cleaner
I just realized this thread is in TGIF - now that's funny......:drinkup
 

Kiwi Tussock

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Joined
May 27, 2011
Messages
26
Location
New Zealand
Hey, whats TGIF stand for? Does the last letter of the four continue with uck-ups?

Thanks for the replies guys and RayF, as Im pretty much a non-welder, that would impress me if you could just blow out that sized bolt with a gas axe. I don't think I could watch. :eek: :notworthy
You've obviously got more skill than this fella. You comin' over this way sometime soon? :) Bring one of those blind sleeve insert with ya. It sounds brilliant. :D

It was hosing down yesterday and infact last nite it was so unseasonably cold, we had to light the fire! hmmmm odd for middle of summer. Should be up in the 30's C.
Today I hope to get back at the ol'girl.
 
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