Need to know how to get a broken bolt out of block help?

7491 Views 43 Replies 20 Participants Last post by 69 SS396, Jun 13, 2012

HKDUP87

Discussion Starter · Jun 11, 2012

I have a new bolt broken off in my block. On youtube they show how with a left handed drill bit and also say an easy out isn't the best they break off. I don't have a welder to try so what's the best way you have done it? It's a 3/8 new bolt in the block. I'm sure it must be a soft bolt it broke with only 30 lbs on the torque wrench .:dontknow:
Thanks

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SINISTER

· #2 · Jun 11, 2012

I'm guessing the motor is installed in car?
Since the bolt is soft,hit it with a sharp punch.
Start with small bits and lubricate with PB blaster.
Work your way up with larger bits until most of the bolt is gone.
Drilling straight is very important.
Once most of the bolt is gone,the thread portion should remove easily.

gilby

· #3 · Jun 11, 2012

HKDUP87 said:
It's a 3/8 new bolt in the block. I'm sure it must be a soft bolt it broke with only 30 lbs on the torque wrench .:dontknow:
Thanks

..you might want to get grade 8 bolts,that cheap stuff you got sound like its made of tin..

oke:
..X2 on what Sinister saids..:beer:

SINISTER

· #4 · Jun 11, 2012

Grade 8 bolts can tear up the threads in the block if they are rusted badly.
Easier to remove a soft bolt than repairing threads...but they both suck.
I save every nut,bolt and washers from my tear downs for this purpose.
You can usually tell when a bolt is getting weak...but not always.

fauxrs

· #5 · Jun 11, 2012

SINISTER said:
Grade 8 bolts can tear up the threads in the block if they are rusted badly.
Easier to remove a soft bolt than repairing threads...but they both suck.
I save every nut,bolt and washers from my tear downs for this purpose.
You can usually tell when a bolt is getting weak...but not always.

Its his brand new crate motor, still on the stand

Is the bolt broken flush with the block surface? does it protrude or is it deep in the block, what grade was the bolt that was used, if its as soft as you say I would go ahead and try the easy out if the bolt is of such poor quality, easy outs break when trying to remove ancient stuck bolts, not brand spanking new cheap bolts in clean threads.

Make sure you understand or know the quality of the bolts you buy in the future - "steel" isnt good enough by any measure. Exhaust manifold bolts are going to get heat cycled alot, I would never do anything less than grade 5, though I too would lean towards grade 8 for this application.

It might also be wise to get a bottoming tap in the correct thread pitch and chase all the threads - clean threads make life a ton easier.

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HKDUP87

Discussion Starter · #6 · Jun 11, 2012

I was short 2 bolts and the rinky-dink hwd store bolt box said steel but they probably put china crap in the bin. Engine is new and on the stand everything is new.

HKDUP87

Discussion Starter · #7 · Jun 11, 2012 (Edited)

fauxrs said:
Its his brand new crate motor, still on the stand

Is the bolt broken flush with the block surface? does it protrude or is it deep in the block, what grade was the bolt that was used, if its as soft as you say I would go ahead and try the easy out if the bolt is of such poor quality, easy outs break when trying to remove ancient stuck bolts, not brand spanking new cheap bolts in clean threads.

Make sure you understand or know the quality of the bolts you buy in the future - "steel" isnt good enough by any measure. Exhaust manifold bolts are going to get heat cycled alot, I would never do anything less than grade 5, though I too would lean towards grade 8 for this application.

It might also be wise to get a bottoming tap in the correct thread pitch and chase all the threads - clean threads make life a ton easier.

It's at the top of the block maybe one thread down from the opening screwed down at 30lbs. so it's tightened down and broken almost to the surface of the block. grade unknown probably labeled wrong said steel but broke of at 30lbs so it's got to be soft. I was using grade 5 till the last two my fault.

mrbsa

· #8 · Jun 11, 2012

I would try the easy out. Get the correct size easy out. Try to get a good placed center punch in the middle of the bolt. Then start with a small drill. Try to get the drill as straight as you can. A second person helping is good for this. Then slowly work you way up to the correct size drill for the easy out. Be very careful. Work the easy out into the hole. Then gently try to turn the easy out and see if the bolt moves. If not heat the area around the bolt and try again to turn it. Before you start put lots of oil or lubricant on the bolt and let it soak in. The other way is if you have a welder weld a nut to the top of the bolt. You have to be a good welder to to this. Place the nut on the bolt and weld in the center of the nut. The heat from the weld helps losen the bolt, then just turn the nut with the wrench. If none of this works, go to plan B.

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69 SS396

· #9 · Jun 11, 2012

Be very, very careful with the small drill bits as they can break off also.

They are hardened so getting them out or drilling through is a batch after they break.

mrbsa

· #10 · Jun 11, 2012

X2, on the be very very careful with small drill bit. In fact I would not use smaller than 1/8. But look at the size needed for the proper easy out and then figure out what size bit to start with.

HKDUP87

Discussion Starter · #11 · Jun 11, 2012

69 SS396 said:
Be very, very careful with the small drill bits as they can break off also.

They are hardened so getting them out or drilling through is a batch after they break.

That's why I'm here I want to do it right so I'm on youtube also. I'm sure this bolt should be soft with the pressure it took to break off only 30lbs and it twisted off not snapped off I could feel it. My last bolt to boot.

dirtpoor

· #12 · Jun 11, 2012

It shoudnt be tight unless you bottomed it out. Also you just put it in so it's not
Rusted. I would use a left hand drill bit:dontknow:

SINISTER

· #13 · Jun 11, 2012

Bits are easier to remove than en easy out..as they usually break at the drill.
Easy out usually break off at the bolt.
All bolts should have markings on the head to indicate strength.
I Save everything from all my projects into jars for later use...comes in quite handy.
Buying cheap bolts at an expensive price from the local hardware store really sucks.

OldChevysNeverDie

· #14 · Jun 11, 2012

Check for damaged exposeed female threads and debris in the hole. A small chip can ruin your whole day when you try to get a broken bolt out.

HASBEEN

· #15 · Jun 11, 2012

In our mchine shop, we deal with them on a daily basis. Just like it`s hard to find quality bolts nowadays, it`s hard to find quality bits and extractors as well.

The left hand bit usually works (you`ve gotta drill anyway for an extractor/ezout)

Since it was going into "new" threads, then it`s probably not "seized" and will spin out
with very little effort if you can get ANYTHING to bite on it. I would first try to spin it out with a very sharp pointed punch. Just start you a dimple towards the outer edge, then once you have a deep enough cavity, angle the punch to put counterclockwise force on the bolt while you tap.

Another easy method is to lay a nut over the top of the broken bolt and weld "thru" the nut to the bolt, fill the complete interior of the nut up with bead. Cool the nut down with a cup of cold water a tea spoon full at a time, then put a wrench on the nut.

Both methods have worked lots for me but I also have been frusted W A Y too many times.

Good luck....sorry for your troubles...

Hasbeen

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mrbsa

· #16 · Jun 11, 2012

I agree with has been. I would try to spin it out with a sharp center punch first. I forgot about that method. Just angle the punch at the edge of the top of the bolt and tap it in the correct direction. Rightsy tightsy, leftsy loosey. If the god of the gear heads is in a good mood and likes you it should just start to move, and you can work it out far enough to get a grip on it with the pliers.

Bobby78

· #17 · Jun 11, 2012

I think I said a left hand drill bit last night in your other thread? Anyway, that should work.
Another thing to think about and maybe you don't want to hear it but I'll say it anyway, be careful with the cheap stuff. Yeah I saw your post about realizing the hardware store sold you cheap bolts. But don't forget the cheap harbor freight tools. Those cheapy pittsburgh torque wrenches may or may not be anywhere near accurate. So while you say it's only torqued to 30 ft lbs it could be more. And that could be why the bolt broke. There's a reason that quality tools like snap-on, matco, mac, cornwell, etc sell torque wrenches for a few hundred dollars. See if you can borrow a better one from someone. Also remember to back off the settings before putting them away. Don't leave them set when not in use. It affects the calibration. And don't ever use them as breaker bars or long ratchets in either direction.

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HKDUP87

Discussion Starter · #18 · Jun 11, 2012

Bobby78 said:
I think I said a left hand drill bit last night in your other thread? Anyway, that should work.
Another thing to think about and maybe you don't want to hear it but I'll say it anyway, be careful with the cheap stuff. Yeah I saw your post about realizing the hardware store sold you cheap bolts. But don't forget the cheap harbor freight tools. Those cheapy pittsburgh torque wrenches may or may not be anywhere near accurate. So while you say it's only torqued to 30 ft lbs it could be more. And that could be why the bolt broke. There's a reason that quality tools like snap-on, matco, mac, cornwell, etc sell torque wrenches for a few hundred dollars. See if you can borrow a better one from someone. Also remember to back off the settings before putting them away. Don't leave them set when not in use. It affects the calibration. And don't ever use them as breaker bars or long ratchets in either direction.

Cool got it I will try the center punch first then the left hand drill bit if needed. I also have an ezout set.

DrPepper

· #19 · Jun 11, 2012

And don't forget to chase the threads before you start work. The two best tool sets I own are a tap & die set and a thread chaser set. They have saved me a ton of work even on new parts.

horseman

· #20 · Jun 11, 2012

No body mentioned the wax method! ?????????:???:

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