Drilling out broken bolts

[dlcwent]

Hey guys, what tricks do you use to get your drill centered when you have to drill out a broken bolt. I've seen a couple of jigs make for certain applications like starter bolts. I'm curious how you center. Assuming you can't get a ***** punch at the bolt you have to drill. Any ideas that anyone can pass along?

 

[dlcwent]

Any previous threads that someone can put up a link to??

 

[Craptain]

I have had limited success by using a dremel to grind a flat area to get the punch to work better, but it is still an approximation most of the time.

 

[dmw16]

I usually eyeball it with a center punch. Typically that's close enough because you don't need to drill out the entire bolt before you can remove it. Since there's a compressive load on the pin once the wall is thin enough it will collapse.

 

[lametec]

I haven't drilled a bolt since I got a welder.

In other words, consider this yet another reason why you should own a welder.

 

[Doug Arthurs]

I just removed some M6 x 1.0 bolts that sheared off on a machine tool. Used a ***** punch to get the center mark as close as possible then a LH drill. All four came out clean. Of course since they were mechanically sheared off and not rusted in it went very easy.

 

[AntiqueCarNut]

I've had good luck with a Quik Center tool. There are 3 or 4 kits for various size SAE and Metric bolts. Not sure if these are still available.

Youtube video

 

[dlcwent]

I haven't drilled a bolt since I got a welder.

In other words, consider this yet another reason why you should own a welder.

I've used that trick. But you have to have enough bolt to weld a nut to.

 

[3 Gun Shooter]

I have taken out a whole bunch of broken bolts and taps. I use a diamond grinding bit in one of my die grinders. Create a nice divot in the center of the bolt. For bolts my first choice is a reverse or screw machine drill bit. Many times backs it out. The 'easy outs' I like are the square ones if I use one.

If you break a tap never touch it with a drill, if you can not back it out with a little tap of a punch and hammer you'll need to cut the flutes to get it out.

 

[sberry]

I hit it with a punch but I can play a little and pretty hit up where I want to drill. I wish I would have saved a drill out scrap a while back, I was feeling lucky and showing my helper and punched right thru the center of one about 3/4 long.
I weld them out if I can and over the years face it less as I improve most things I own or not break it in the first place.

 

[crawler07]

I have a set of quick centers and they are awesome. Not shown in the youtube video but they are great for center drilling small diameter rod as well. The welding method is also another great way to extract broken bolts.

 

[f150skidoo]

When i broke the turbo bolts on my JD diesel the bolts sheared off flush to the flange so i grabbed a Chinese 3/8" drive extension and ground it to a point and then welded it to the bolt since i did'nt get enough bolt top weld a nut on. But when i have to drill a bolt out i use a center drill bits from the mill since they won't walk like a small S&D bits.

 

[Strouty]

I have taken out a whole bunch of broken bolts and taps. I use a diamond grinding bit in one of my die grinders. Create a nice divot in the center of the bolt. For bolts my first choice is a reverse or screw machine drill bit. Many times backs it out. The 'easy outs' I like are the square ones if I use one.

If you break a tap never touch it with a drill, if you can not back it out with a little tap of a punch and hammer you'll need to cut the flutes to get it out.

For taps, you can get a tap remover.

As for removing bolts, I have had terrible luck welding to anything, they are either flush or in a bad area and I can't get any penetration on the remaining part of the bolt. I have tried welding washers to them, then nuts to the washers and nothing ever worked.

 

[Tig Master]

Tig welder and a couple of minutes and out they come have removed 100's of brokrn bolts from 8/32 to 3/4" never been stumped.
http://www.weldingtipsandtricks.com/remove-a-broken-bolt.html

http://www.fordgarage.com/pages/studremoval.htm

T

 

[bgarrett]

I looked at the quick center website which says it can work on *ANY* broken bolt but the video shows that you must have several threads sticking out,. How does that work for bolts that are broken off flush?

 

[dlcwent]

I've had good luck with a Quik Center tool. There are 3 or 4 kits for various size SAE and Metric bolts. Not sure if these are still available.

Youtube video

I looked at the quick center website which says it can work on *ANY* broken bolt but the video shows that you must have several threads sticking out,. How does that work for bolts that are broken off flush?

bgarrett...did you check this out?? It's got my interest.

 

[bgarrett]

thank you dlc. Your video is better than the one I had watched

 

[dlcwent]

They show how it works on a bolt broken off flush.

 

[dogdog]

maybe you are looking for this thread.... there is one post that have a special tool some guy posted call quick center. looks pretty neat.



http://www.garagejournal.com/forum/showthread.php?t=309668&highlight=bolt

 

[fourjeepin]

Re: Home Depot Clearance Thread 2015

For taps, you can get a tap remover.

As for removing bolts, I have had terrible luck welding to anything, they are either flush or in a bad area and I can't get any penetration on the remaining part of the bolt. I have tried welding washers to them, then nuts to the washers and nothing ever worked.

The washer + nut was what I was going to suggest. It has worked for me.

 

[sublime68charger]

Good luck dlc!

I'm following along as I have 3 broken bolts that I need to get out on my atv!

 

[joe49]

As for removing bolts, I have had terrible luck welding to anything, they are either flush or in a bad area and I can't get any penetration on the remaining part of the bolt. I have tried welding washers to them, then nuts to the washers and nothing ever worked.

Tig or stick with a specialty rod like cronatron eagle, Mig is not as good but can work, too.

 

[dlcwent]

How are you making out with the bolts sub?

 

[theoldwizard1]

LH drill bits !

Might as well start out going in the right direction.

 

[Bdgjr215]

After you center punch the broken bolt,use a center drill,then a pilot hole ,then the
Appropriate size drill bit for your easy out.

 

[sublime68charger]

How are you making out with the bolts sub?

wont get to work on them till Saturday,

I have left handed drill bits now and some good metal bits as well and a better extractor kit!

plan is use my good metal bits and drill through the bolts and if then start to turn I'll switch over to the left hand bits so hoping they then spin out!

if not I try the extractor as well.

Ill snap some Pics and post up with how it goes!

 

[dlcwent]

Sub, I may be wrong, but I think you should start with the left handed drill bits first.
Pictures are always good. Make sure you get a close up of the broken off drill bit. And I hope that doesn't happen to you. I just had to say it.

 

[Doug Arthurs]

yes start with the lefties.

 

[wasfuzz]

Use reverse twist drill bits is also a trick!

 

[Lassen Forge]

Dose the threads with Kroil, or at least some 0W20 synthetic (or both!!) first. Serious about this. When the bolt breaks, it usually preloads or galls the threads down the hole (especially if it broke from bottoming), and you want to break that galling down there, and get some lube between the metal surfaces.

The other trick is to use a small center punch and gently try to tap the broken stud in the right direction (usually meaning left)... the down + spin will help break the gall and get the kroil between the threads.

 

[sublime68charger]

I got one done 2 more to go!

Pic of broken bolt
got good metal bits and did small then bigger going with right bits, then switch to left bit hoping old would spin out,
Nope not really I kept sizing up the bits till I got to the size for tapping and then just tapped out to the size bolt 8mm and done!

1 down 2 more to go!

 

[sublime68charger]

Pic of tapped out with new bolt in

Okay my posting break is over back to work for me!

 

[trainer]

For a bolt broken below the surface a self centering hinge bit works very well.

 

[sublime68charger]

2nd bolt out!

Pic of small hole in bolt!

 

[sublime68charger]

Next is bigger hole in bolt!

 

[sublime68charger]

Dlc just for you pic of my broken left turn drill bit!

2nd bolt other then the bit breakin went just fine,

Was crusin on the third bolt had drilled out and was using the tap turn in, back out turn in and snap broken tap off in hole


#%^**€€<~}~~{}%^**£++€<#~

Or there a bouts had to drill out hole below broken tap and had bigg egg shape hole total ruined nut weld on the frame on that one now have bolt with free wheelin nut for that bracket!

But Atv is 3/4 back together now and the heated grips are working again!

It's just never as nice as you would like it to go when dealing with broken bolts!

 

[Tig Master]

No special rod just er70s6
does it every time This is not rocket science.

If you just build it up first that is all you need in many cases a vise grip will twist it out without a nut welded on.Just let it cool off to the touch before you remove it .

T

 

[dlcwent]

Dlc just for you pic of my broken left turn drill bit!

2nd bolt other then the bit breakin went just fine,

Was crusin on the third bolt had drilled out and was using the tap turn in, back out turn in and snap broken tap off in hole


#%^**€€<~}~~{}%^**£++€<#~

Or there a bouts had to drill out hole below broken tap and had bigg egg shape hole total ruined nut weld on the frame on that one now have bolt with free wheelin nut for that bracket!

But Atv is 3/4 back together now and the heated grips are working again!

It's just never as nice as you would like it to go when dealing with broken bolts!

Sorry if I cursed you by saying that. I'm glad you got the deed done.

 

[Dave RI]

Depending on the size of the bolt and how tight it is sometimes you can use the center punch to back the piece out by creating a punch mark on the outside of the dia and angle the punch to back the bolt out as you tap the punch . There is always the edm hole popper , not everyone has one of coarse find a machine shop in your area that may do EDM work they should have one .



Dave