How to remove a Broken Bolt
#1
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How to remove a Broken Bolt
There are many different methods.
This is one of the more common methods using an EZ-Out
This method works best on bolts that broke due to being over tighten.
The EZ-out method has little success on cross threaded or rusted bolts.
The tools needed are few.
![](https://www.miataturbo.net/attachments/engine-performance-56/63522-how-remove-broken-bolt-dscf5547.jpg?dateline=1357313066)
Drill
Proper size drill bit
A good sharp center punch
Hammer
Crescent wrench
Proper size EZ-OUT
There is two different styles of EZ-out, A left handed spiral flute and a straight flute.
I will be using a spiral flute in this removal.
The spiral flute will screw down and get a firm “bite” on the inside of the broken bolt.
First with the hammer and center punch, knock a good divit as close as possible to the center of the bolt.
![](https://www.miataturbo.net/attachments/engine-performance-56/63523-how-remove-broken-bolt-dscf5548.jpg?dateline=1357313066)
This is done so the drill bit will not walk around when you start to drill.
![](https://www.miataturbo.net/attachments/engine-performance-56/63524-how-remove-broken-bolt-dscf5549.jpg?dateline=1357313066)
Now with the drill bit in the drill motor.
I am using a 1/8 inch drill bit, the broken bolt is a 8mm (5/16ths)
![](https://www.miataturbo.net/attachments/engine-performance-56/63525-how-remove-broken-bolt-dscf5550.jpg?dateline=1357313066)
Drill appox. 1/8th to 1/4th inch down the center of the bolt.
Drill as straight as possible.
Some times it will be necessary to drill all the way through the bolt.
![](https://www.miataturbo.net/attachments/engine-performance-56/63526-how-remove-broken-bolt-dscf5551.jpg?dateline=1357313066)
Blow all the metal chips out of the bolt hole.
![](https://www.miataturbo.net/attachments/engine-performance-56/63527-how-remove-broken-bolt-dscf5552.jpg?dateline=1357313066)
Now take the EZ-Out and tap in to the hole you just drilled.
![](https://www.miataturbo.net/attachments/engine-performance-56/63528-how-remove-broken-bolt-dscf5553.jpg?dateline=1357313066)
Now using the square on the back end of the EZ-out.
Gently apply pressure to the broken bolt, until you feel movement.
If you apply too much pressure, and snap the EZ-Out off in the hole, you will have more serious issues.
There are many different methods.
This is one of the more common methods using an EZ-Out
This method works best on bolts that broke due to being over tighten.
The EZ-out method has little success on cross threaded or rusted bolts.
The tools needed are few.
![](https://www.miataturbo.net/attachments/engine-performance-56/63522-how-remove-broken-bolt-dscf5547.jpg?dateline=1357313066)
Drill
Proper size drill bit
A good sharp center punch
Hammer
Crescent wrench
Proper size EZ-OUT
There is two different styles of EZ-out, A left handed spiral flute and a straight flute.
I will be using a spiral flute in this removal.
The spiral flute will screw down and get a firm “bite” on the inside of the broken bolt.
First with the hammer and center punch, knock a good divit as close as possible to the center of the bolt.
![](https://www.miataturbo.net/attachments/engine-performance-56/63523-how-remove-broken-bolt-dscf5548.jpg?dateline=1357313066)
This is done so the drill bit will not walk around when you start to drill.
![](https://www.miataturbo.net/attachments/engine-performance-56/63524-how-remove-broken-bolt-dscf5549.jpg?dateline=1357313066)
Now with the drill bit in the drill motor.
I am using a 1/8 inch drill bit, the broken bolt is a 8mm (5/16ths)
![](https://www.miataturbo.net/attachments/engine-performance-56/63525-how-remove-broken-bolt-dscf5550.jpg?dateline=1357313066)
Drill appox. 1/8th to 1/4th inch down the center of the bolt.
Drill as straight as possible.
Some times it will be necessary to drill all the way through the bolt.
![](https://www.miataturbo.net/attachments/engine-performance-56/63526-how-remove-broken-bolt-dscf5551.jpg?dateline=1357313066)
Blow all the metal chips out of the bolt hole.
![](https://www.miataturbo.net/attachments/engine-performance-56/63527-how-remove-broken-bolt-dscf5552.jpg?dateline=1357313066)
Now take the EZ-Out and tap in to the hole you just drilled.
![](https://www.miataturbo.net/attachments/engine-performance-56/63528-how-remove-broken-bolt-dscf5553.jpg?dateline=1357313066)
Now using the square on the back end of the EZ-out.
Gently apply pressure to the broken bolt, until you feel movement.
If you apply too much pressure, and snap the EZ-Out off in the hole, you will have more serious issues.
![](https://www.miataturbo.net/attachments/engine-performance-56/63529-how-remove-broken-bolt-dscf5554.jpg?dateline=1357313066)
#5
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I am working on another method to show you for rusted bolts.
^^ This, alot of fire, make it glow!
Most the time that is becuse the hole is not large enough, I commonly see this with people that have not used ez-outs alot.
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I joined the "only thing I've managed to do with an EZ out is break it" club this weekend. First and probably last time using one.
#14
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My last EZ out attempt actually worked!! Joe, remember that AC bracket bolt that causes an oil weap when it's missing (or, in my case, broken)? I actually removed it easily with an EZ out. I was shocked. Must be living right.
I think the key with an EZ out is that it doesn't hurt to try but don't apply significant torque. It either starts backing out pretty effortlessly or you should be trying another method.
I think the key with an EZ out is that it doesn't hurt to try but don't apply significant torque. It either starts backing out pretty effortlessly or you should be trying another method.
#15
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It has been my experience that the spiral one breaks a whole lot easier then the square ones. I have broken a few spiral ones over the years but have never broken a square one, it usally just lets go and starts reaming out the hole. It doesn't screw itself in like a spiral one does and I don't think it is heat treat hardened as much as a spiral one.
#17
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You have no idea how badly I would love to plop down the couple grand that one of these babys cost. Just a simple tap disintegrator with a magnet base would be all sorts of winning. I never looked heavily but if they made a magnet base model small enough to fit in an engine bay with the engine in it, it would be amazing.
#18
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Heads off, and A LOT. I literally could have bought a running NA for what I paid, but it wasn't just the bolts. I managed to break off 4 of the 8 exhaust manifold bolts in each head while trying to R&R the broken iron manifolds. I broke 2 EZ-Outs before throwing my hands up and then ripping off the heads and the 9,000lb iron intake manifold and paying someone to fix it. I took the opportunity to have the heads completely rebuilt and also install some headers. Runs better and get more mileage now that all the valves seal ("more" is a relative term with a Ford FE.) Funny how that works...
I honestly didn't look, the total was hideous. I didn't WANT to know after 16 new valves, seats, seals, machine time and shop hours to get it all put together. The shop does GREAT work, but yee gods, they are expensive. I'd not hesitate to trust them with anything... if money was no object. Needless to say, I will think twice and explore many options before using them again.
I honestly didn't look, the total was hideous. I didn't WANT to know after 16 new valves, seats, seals, machine time and shop hours to get it all put together. The shop does GREAT work, but yee gods, they are expensive. I'd not hesitate to trust them with anything... if money was no object. Needless to say, I will think twice and explore many options before using them again.