20200 Thread Chaser

I was replacing the o2 sensor on a bmw 3.0 and I could tell the threads were galling and if I were to finish removing the sensor, I may not be able to get the new one back in. I found this one on amazon and sure enough the 18 x 1.5 was the correct match. I strong armed the sensor out and the threads were in bad shape. All the threads from the sensor were gone and much of the material was in the the threads of the exhaust manifold. I used a deep impact socket and a breaker bar. The o-ring proved very worthy here as it slid up in the socket and held its place without falling out. Even being pushed all the way in the socket, it left plenty of the chaser tool exposed. I began turning and applying pressure to get it threading into the exhaust manifold. Since this isn't a tap for true thread cutting, it would get tight and hard to turn. The name of the game here is tighten it and back it off, back and forth, around an 1/8 to 1/4 turn at a time. This is why I used the breaker bar, a ratchet would continually have to have the direction switched to go back and forth which is a pain. As you keep threading it in further and doing the back and forth, you can feel it loosening as it clears threads. Every time you back it off, you try to slightly advance the turn, until you get all the way through. I sprayed a little WD40 occasionally to help with the friction as it will get warm to hot. In conclusion this thread chaser worked perfectly and ultimately saved the day! Lisle tools have always been a quality go to for me. The thought of replacing the exhaust manifold and the headaches that one can encounter doing that job, were happily avoided. I helped my son do this job. The value of patience and making sure you have the right tools to do the job, really shined through here! BTW: I used a standard o2 sensor socket to start with. After about 1 full turn it got real tight, where then the socket splayed and jumped, which suggested the threads were galling. Ultimately I had to clip the wires on the sensor and remove the upper parts of it to get a regular deep well socket on to get it out. An o2 sensor socket is longer than a standard deep well socket. Hopefully this may prove helpful to someone else with the same problem

Every once in a while I run into a spark plug or oxygen sensor that fights me on the way out. I've run into enough galled threads that I scrupulously use anti-seize compound on both, but anti-seize won't help you if the threads are damaged or full of trash-- or if the last guy forgot to use it. I've found that if I'm careful removing things, I can usually clean up the threads with a thread chaser and they'll be fine. I don't like using a tap if I can avoid it because taps tend to remove more material, and I want to preserve as much of the metal as I can. Most times a thread chaser is enough to get things back on track. I've used Lisle tools for years. They are usually a good balance point between quality and price. This chaser is no exception. I use this whenever I replace an oxygen sensor and sometimes when I replace spark plugs. The $7 that it costs is NOTHING compared to the headaches that it will solve if you accidentally damage or cross-thread something. If you do your own maintenance work, you should have one.

My differential had a stripped fill plug and I need a large thread chaser to clean up some stripped threads, this worked very well and cleaned up the threads for my fill plug. Unit seems to be high quality and held up well during my usage.

To be honest I was thinking I purchased an o2 sensor thread chaser. When it came it said spark plug thread chaser. I was torn because I actually needed one but it wasn't what I thought. I recently got a long reach swiveled spark plug socket which I can use for many of the engines around the house but 1 in particular I had trouble putting a new plug in to. I used this and it went in like new so I can't complain. My mistake couldn't have had better timing. I guess it was meant to be. It has both sizes for cleaning up the threads so that's a bonus! It seems to work flawlessly!

Works great for cleaning your bunghole.

I could not be happier. After extracting my Oxygen sensor, I noticed it had stripped the threads along the process. I searched and searched for thread chasers and they all fell short. All were made of what they said tough sturdy metal. All stripped on my exhaust pipe thread. Except for this one! It made quick work of my warped threads and I was able to install the new O2 sensor. Made truly tough as it claims and at a great price. I’d purchase again if I had to.

This is a must have in your toolbox. Pulled a rusty plug out of a generator and the threads in the head looked HORRIBLE. I cut a diagonal slot in the old plug threads to create a flute thinking I could save it that way, but didn't love how it felt when I went to crank it in. Threw the ten bucks at this tool, loaded it up with grease and ran it in an out a couple of times and was super happy with how they looked all said and done. Little pro tip, (for added peace of mind) is that you can take a long and narrow funnel, and stick the funnel opening on the end of your shop vac and then stick the small end of it down in the plug well to suck up any debris.

Excellent tool save me a lots of time to fix the streep thread on my 2001 740i replacing the O2 sensor..... recommend this tool

Did amazing! I can now thread my spark plug easily by hand. Don't forget to put some kind of grease on it to catch any filings. In my case, I had bearing grease on hand.

I was concerned that this would make the threads worse but it worked perfectly. Remember to vaccum or blow out the cylinder after to get out any metal filings

It did its job to make a new thread.

For those who removed their sparkplug and can't get it back in. This is the tool to use. Don't stress take your time. Don't forget to use grease. I used anti seize. When you feel resistance fight through it. You got this.