10 Tricks to remove that Stuck, Seized, or Stripped Bolt/Nut

One of the biggest frustrations when disassembling a vehicle for restoration, or even repair, is the dreaded seized or stripped bolt. Stuck hardware occurs when a bolt or nut gets corrosion between the threads and they won’t budge. Many times this leads to breaking the bolt off and having to drill and retap the hold or trying to remove it with a bolt extractor. I won’t even mention what happens when the drill, tap, or extractor breaks off in the same hole!!

Below are my top 10 ways to deal with getting these suckers extracted without wrecking the precious part they are in!

1.Blunt Impact/Force- This is usually my first step when attempting to loosen stubborn bolts. I ALWAYS use this method before I begin removing exhaust studs from a cylinder head. There are a few methods for this. One is to hit on the head of the bolt in the center with a chisel or punch. Another is use an impact wrench/gun and hit it a few brief times in reverse and forward. Either of these methods work on the theory of freeing the corrosion bond between the threads by vibration or impact. It works sometimes on lightly seized bolts, but isn’t a 100% winner every time. But keep in mind it can be combined with many of the other methods to help make the job easier.

2.Heat- If you paid attention in chemistry class you would have learned that when you heat and cool metal it expands and contracts. The way that I have used in the past is to heat the head/body of the bolt until it is almost red hot. By doing this the bolt expands due to the heat, and when it cools it will contract thus breaking the corrosion in between the threads. A similar method is to heat the area around the bolt to make the hole it is threaded into actually expand and open up a little bit so that the bolt fits a bit looser and can be threaded out. Use of an impact wrench/gun helps when initially breaking it loose since the force from the hammering of the impact wrench breaks the corrosion apart as well. Use penetrants like Kroil or CRC Freeze-Off to aid in the removal process.

3. Relief Cuts- This method is my “sure-fire” method for removing most stripped bolts/nuts. It isn’t as clean/civilized as the others, but it is a heck of a lot faster! With this method you will be putting 2-3 cuts in the bolt head or nut. You want to cut just enough that you are almost all the way through the head of the bolt or the nut. You then can hit the cuts with a chisel and a hammer a few times, thus splitting the nut or bolt and relieving the tension on them. With nuts you can normally just split it off of the bolt, clean up the threads, and install a new nut. With bolts you can use some locking jaw pliers to grab the bolt head and turn the bolt out, usually the relief cuts will let the pliers squeeze the head of the bolt enough that you can turn it out easily.

4.Rock the bolt- This is another one to try early-on in the process, and in conjunction with other methods. You want to slowly work the bolt/nut back and forth. I like to take a ratchet and loosen the nut/bolt a little bit until it gets a bit of tension behind it again, then go back the other way and turn it almost to where you started, before loosening a little bit further than last time. As you expose some of the hidden threads, you want to spray some penetrant on the those threads so that the penetrant works its way back into the hidden threads. It can be a slow process, but I’ve gotten some pretty stuck bolts out this way with a little bit of patience.

5.Drill’er out!- This is the same concept as the relief cuts with a couple small twists or surprises that can occur along the way. I like to use this one as more of one of my last ditch efforts, or if the bolt has broken off flush with the surface. What you want to do is take a small drill bit and drill all the way through the bolt. This uses a bit of the chemistry a few of the other methods use. It heats the bolt by drilling it, and it also makes a hollow portion in the bolt so it can contract more as you attempt to remove it. I’ve had times where just drilling the bolt will allow the bolt to turn out quite easily. Other times you may have to keep stepping up your size of the drill bit with a drill index until you are just a bit smaller than the diameter of the bolt. At this point you may be able to carefully chisel or break the bolt apart in the hole. You can then extract the pieces and clean the threads back up with a tap set or a universal tap tool.

6. Weld’er Up!- This is one that can be used if the nut or bolt head is so severely stripped you can’t turn it with locking jaw pliers, or if the head is broken off the bolt. You can simply take a washer and a bolt of a slightly larger size and tack weld it to the bolt body. Once you have it tack welded, I like to fill the nut with weld and run a bead around the base of where it meets the bolt body. This allows you to put a socket on the bolt again, as well as puts heat into the bolt that will allow it to expand and contract, breaking some of the corrosion. I prefer to use a Mig Welder to do this job as it allows for a little more control than with a stick welder.

7. Air Hammer/Chisel- This combines a few of the methods mentioned. But can be used when the bolt head is stripped. You basically chisel/hammer it so that the bolt loosens. Have had it work with moderate success, but needs to be on a bolt/nut that is an open area.

8. Bolt or screw extractor- There are many styles/gimmicks. Some work, but many do not. They use hardened bits that grab into the inside of the bolt or nut to remove it. Many you have to drill a small hole in the bolt, then thread these in. Just whatever you do, DO NOT break the extractor off inside the hole, or you are in for a long, horrible process. Normal drill bits will not touch these, so you will need specialty drill bits to drill through them.

9. Pipe Wrench- This is a pretty basic way to tackle a stripped bolt, and most everyone has a pipe wrench kicking around their shop. Tighten the pipe wrench down on the bolt/nut and as you crank on the bolt with the pipe wrench, it actually grabs harder onto the bolt head. Just watch you knuckles if it slips off!

10. Reinstall bolts that surround the stuck bolt/nut- Sometimes a number of bolts in a area will hold a part on. Occasionally these are meant to be removed in a specific order. Make sure you check your repair manual for any installation/removal order. If none, I like to work from the center and work your way to the outside. Reinstalling some of the bolts around the stuck bolt may take some of the force off of the stuck bolt and allow you to remove it.

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  • Sean Bayliss

    August 29th, 2011

    Pretty much the way you did it, I have become accustom to using Kroil, from Kano labs. it is the best penetrating lube out there. I have seen it get rusty bolts loose where others will not.

  • Halley@allen head bolt dimensions

    November 22nd, 2011

    I usually just hammer it out of frustration, so this post is like heaven sent to me. I recently bought a Mig Welder, which is as you said, much easier to control. And the heating process works like an angel.So thank you for the advice and keep up the great work!

  • joe suarez

    March 22nd, 2012

    Thanks for information. I have a seized allen nut in a expensive airshock. Will not come out.. Trying to drill out but am concerned about damaging threads.. Allen screw is a set screw. any suggestions for removing broken allen wrench in set screw

  • Jeff

    June 8th, 2012

    Have an O2 sensor that is seized up in the exhaust pipe and can’t get it out. Stripped the nut. Don’t have a lift. Need help

  • Robert

    October 5th, 2012

    This is what I have found works best as a lubricant/penetrant and has worked on every stuck nut and bolt I’ve had to deal with…

    PB Blaster…

    It also works great at removing weatherstripping, breaking the glue up into a goo that can be easily wiped off..and stickers..

    Many uses for this stuff…

  • John McKinney

    October 5th, 2012

    Another method is to use a left hand twist drill bit. Have had great results with this.

  • Rob

    October 20th, 2012

    Well, my smallest bit I started with is stuck in the middle and it won’t drill anymore. I read you didn’t’ even want to mention a stuck bit, but I’m stuck. I’m thinking I have to start a new hole between the bolt and the side and damage the threads a little.

  • Anand Ghurye

    December 17th, 2012

    Very nice information . If the bolt is large enough then you can drill a hole in it , tap it with left hand threads , insert a small bolt in it . Tightening the small bolt loosens the big one .

  • brandon

    September 17th, 2013

    i have a bolt stuck on my lower control arm of my truck the nut is off i can not harm the bolt ive tryed beating it out pb blaster impact and still in idk if the bushing is holding it or not but i need tool or trick to get it out

  • John

    September 18th, 2013

    RE: Joe Suarez –

    I have found that a similar sized torx bit will often grab an allen socket that is rounded or stripped. The blades of the torx shape tend to bite into what’s left of the allen corners. If the torx doesn’t grab firmly, you may be able to go one size up and hammer it into the allen socket. In a real bind, you can get an extra torx bit to sacrifice and put a little JB weld on the blades, then tap it into place in the rounded allen. Just make sure to degrease everything first or the JB is worthless, and have patience. Let the JB set up for a full 24 hours before you attempt to turn the setup. Also, don’t get carried away with the JB weld. If you use to much and it squishes out of the allen socket and bonds to the threads, you will only make things worse.

  • John B

    September 23rd, 2013

    Thank you. I’ve been looking for a resource like this for a while.

  • Mike Dunn

    October 2nd, 2013

    I drilled a 1/32 inch hole in the top of the head bolt and squirted PB penetrate into the hole. It works it way down the shaft of the head bolt to the threads.

  • Ali

    October 6th, 2013

    Neded help please! I just broke a bold from oil pump. I try to drill with extractor but is not working. any advice?

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