Introduction: Removing a Broken Bolt or Stud With TIG

Often when a bolt or stud breaks off, it breaks with a little bit protruding above the material it's threaded into. In this situation, it is sometimes possible to use a pair of vice grips or such, to facilitate the removal of the bolt. More times than not though, this won't work for the very reason that the bolt broke in the first place. A worse case scenario is when the fastener breaks flush or lower than flush with the workpiece. Worse again, is when it's a high tensile fastener that has broken off, lower than flush. Being high tensile, it will be difficult or impossible to drill and use an ezi-out or something similar. In all of these cases, there is one method that will nearly always remove the broken fastener. It utilizes the beautiful welding disipline of TIG. Please visit my link below to see this in action, and straight under the video, you will step by step stills and an explanation of each step.

Step 1: The Object With the Broken Bolt or Stud

So here we have an inlet manifold. It's made of an aluminium alloy of some type. It's not important what it's made of. It could of been cast iron, or anything else for that matter, and the following process would still work . In this example, the bolt has broken off leaving nothing protruding. If it had broken off, leaving a section of the bolt protruding above the manifold etc, we could of probably used vice-grips or something similar to remove the broken section of the bolt. In our case, it has broken off below the surface of the material. What's worse is that it's a high tensile bolt, so it would be hard to drill and use an ezi-out etc. We will be using a TIG welder to weld a bolt to the broken section, and remove the culprit using a spanner on the bolt.

Step 2: Showing the Broken Bolt and the Complete Bolt That We Plan to Weld to the Broken Section

In the first photo in this step, you can see the end of the broken bolt that we are going to build up using the Tig welder. In the second photo, I am pointing to the end of the broken stud, with the actual mild steel filler rod that we are going to build it up with. The final photo in this step shows the bolt that we are going to TIG weld to the built up broken bolt.

Step 3: Building Up the End of the Broken Stud With the TIG Welder and Metal Filler Rod

Here we are building up the broken bolt. Once the mound has been created, it's then a good idea to give it a bit of a wire brushing with a stainless brush, and the last photo nicely shows the mound of mild steel that we can now, successfully weld our bolt to.

Step 4: Preparing the Bolt That Is to Be Welded to the Mound on the Extractee

It's a good idea to grind off the zinc, if you're using a galvanized or zinc plated bolt. Not only will it make it easier to TIG weld, but it will avoids the zinc fumes that would otherwise arrise. Zinc vapour is bad for humans.

Step 5: Clamping the Bolt in Position Whilst We Get a Tack Weld Onto It

Here we are clamping the bolt into position, with a pair of vice-grips, so that we can get a tack weld onto it before we remove the vice-grips. Note the nice improvation of using the hole-saw as a spacer. Any handy spacer (that doesn't burn), would of done.

Step 6: Tack Welding the Bolt Onto the Built Up Mound

The title of this step says it all. Here we are tack welding the bolt onto the mound, so that we can then remove the vice grips and TIG weld it properly.

Step 7: Completing the TIG Weld, Now That the Vice Grips Have Been Removed

Again, the title of this step is fairly explanatory. The vice grips have been removed and we put a weld 180 degees from the tack weld, and let it cool for a few seconds. (I know I refer to the first weld as a tack weld, but I didn't even bother rewelding the first weld, as TIG welding is enormously strong and beautiful)

Step 8: Removing the Broken Bolt With a Spanner on the Welded on Bolt

Finally, we simply use a spanner, and the broken section of bolt comes out quite painlessly

Step 9: Admiring the Bolt Welded to The, Now Removed Broken, Section of Bolt

Satisfaction time, as we admire the now removed broken section of bolt

Comments

author
hillmotorsports (author)2016-06-02

Before they learned how NOT to, my sons broke studs off in the aluminum hubs of their race karts. I have had success removing the broken studs by building a "knob" with multiple tacks with my MIG welder, or welding a nut over the broken stud. Sometimes has taken multiple attempts but ultimately has been successful. I use a wrench on the nut, or twist the knob with vice-grips.

author
baecker03 (author)2016-03-22

a person could also drill a hole into the broken off piece and insert some steel rod and weld or glue in place. definitely not a job for a novice.

author
notmuchwear (author)baecker032016-03-23

A glue might do it.

author
kwhit190211 (author)notmuchwear2016-04-11

You can be sure of one thing, glue is not going to work. When your dealing with medal, you need to weld, burn out, or fill over. And, then if you fill over you have to drill and then re-tap.

author
jlepack (author)2016-03-22

The heat from welding helps loosen the broken bolt. Good instructible.

author
notmuchwear (author)jlepack2016-03-22

Good point

author
hjjusa (author)notmuchwear2016-03-23

I've blown a bolt out with an acytylene torch
, just heat it up super hot and hit it with a blast of pure oxygen.

author
notmuchwear (author)hjjusa2016-03-24

How does the oxygen work, and do you think it would work every time. I think maybe it would damage the thread this way??

author
kwhit190211 (author)notmuchwear2016-04-11

Sometimes the threads take a beatinf, but you just have to watch as you melt the bolt out. The smaller the bolt the worse it is using a torch, as you heat up both the broken bolt & surrounding medal.

author
kwhit190211 (author)hjjusa2016-04-11

No guarentee on that one. Doing that, usually causes blow-back. Where a shower of hot sparks comes back to meet you in the face. And, you have to be carefull as you can melt out the hole to a larger size. I've done you method tons of times, burning out bolts on more pipe flanges than i can remember. The well rusted ones are the worse, but sometimes it's the only way you can get the bolts out. And, this is from the 38 years experience as a Journeyman Pipefitter.

author
epplergm (author)2016-03-23

I used a similar method with an arc welder. start with a short piece of steel, angle iron or flatbar. It must be short enough to turn after it is welded on. Drill a hole about the thread size in one end, near the edge. Place the hole over the thread, and weld to the screw, and fill the hole you drilled. let the weld cool, which warms the piece holding the broken screw, and expands the outer thread, and breaks any rust or thread lock if present. After the metal cools from red to just hot, try turning the bar you welded on. Don't come straight out, try turning back and forth and the peice will get easier to turn. Once it frees up, remove the screw. If I have more than 1 broken screw I drill more than one hole in the metal bar, near the corners at the ends and reuse the bar.

author
greenwoodcreations (author)2016-03-23

excellent guide, step by step with a tig. I don't have that style welder, I am old school and still have a stick welder. But i have done the same thing using a 1/32 rod, bring the weld out to the surface and then above. Then i don't use a bolt, i set a correct size nut over the new raised weld and fill the center of the nut in. When it cools down the wrench will bring out the stub the same as in your video. New methods for an old idea, keep passing them on to the ones that care!

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