LOCTITE 243 Automotive Threadlocker Blue - Medium Strength Thread Lock, General Purpose, Oil Tolerant - 6 ml, 1 Pack

I bought this to use on a firearm and I must say I am very impressed. I used loctite 242 and it produced some great success but using it in conjunction with oily areas of the rifle, it seems to cause issues. It appears either I had to carefully apply oil or just never oil the area.Then came this product after reading around. The maximum temperature threshold for loctite 242 is about 200 degrees. With Loctite 243 it's almost twice that nearing 360 degrees. On top of that, it is indeed surface insensitive when you apply it.Before going all crazy with this product, I decided to give it a garage science test. My favorites are Loctite 242, and Rocksett and finally the newcomer, 243. I got a scope mount that had set screws to torque it down. What I did was for each screw I would wipe it completely clean with rubbing alcohol, and simply apply each product. Each product worked as advertised and to unscrew I had to apply above average torque to break loose. Then I cleaned it all again and got the stuff off the screw. I then applied a light oil on the surface and wiped it down with a towel the best I could to get it somewhat dry but still have oil on it that you can't see. The loctite 242, and Rocksett both failed. I could unscrew it by hand after waiting 1 week and it even seemed like it was loose before even trying to unscrew it. With loctite 243, it had the same amount of torque required to unscrew it and it was on really tight. It seems like it is working as advertised.My guess is if loctite 243 fail, it will fail due to high temperature but that is expected on a firearm. It's impossible to really say how hot a firearm can get as it depends on how much you shoot and all that. From reading online military manuals, it appears that the expected temperature range depends on location of the barrel. On a rifle, it appears the average temperature for near the muzzle is about 400-600 degrees and this is shooting approximately 1 round per second until 60 rounds are fired. Of course that is on the surface of the barrel and the question is transferring that heat off the barrel to where the set screws are different questions. It's only a matter of time before this is figured out and I believe so long as whatever it is torqued correctly I shouldn't see any issues.Overall I am impressed with this product. It does work very well and I highly recommend it for firearm folks who are looking for something that can still oil over. You don't have to go all crazy with taking off the oil on the screw when you install whatever it is you're installing. However, I still recommend doing that just to be sure you have the best application possible. From there, you can apply oil to your heart desire without worry about it breaking loose.As a side note, another product I'm looking into is loctite 246. This is the same stuff as 243 where it is surface insensitive, BUT it has a higher temperature threshold. I also notice loctite 246 has a expiration date but the loctite 243 doesn't. Not sure what the shelf life is on this but that is another thing I will monitor on my own.

Genuine Loctite

I really like using Loctite products, they always work as expected. This product it not an exception. It was not easy to find it for a reasonable price, it is overpriced at many sources. But this time the price was acceptable, thanks!

Be sure to degrease screws first for ultra strong hold.

I had some Loctite 242 which I use for many things - from fixing cars, holding screws in for small electronic projects, to building 3D printers. I purchased the 243 version as the specs look like it may work better for my uses.

What can I say but, read the package. It works.

Its the good stuff

Used this to secure the hammer screw that kept backing out on a Henry lever action. Regular blue thread locker didn't work but Loctite 243 worked a lot better around oil.