Threadlocker 242 or 243?

[Dave1899]

I'm confused as to the difference between these two numbers.  They both seem to do the same thing.

242  is a removable strength, general purpose thread locking adhesive especially well suited for fasteners between 6 mm and 19 mm diameter. Protects threads from rust and corrosion.

243 is a removable strength, general-purpose thread locking adhesive especially well suited for fasteners between 1/4" and 3/4" diameter. Tolerant of oil and other contamination. Protects threads from rust and corrosion.

Can I use either one on my air guns?  I've seen 242 listed for mounting scope rails but it seems 243 should do the same thing...They're both Blue...

[Machinist]

Dave:
It appears that Loctite 242 and 243 are essentially the same (both medium strength) except 243 is more oil tolerant.
Try this URL: http://www.xpedio.carrier.com/idc/groups/public/documents/techlit/570-609.pdf
Sorry, I don't know how to make it a direct link, so you may have to do a "copy" and "paste".
Also found other sources that indicate that agree with you on fastener size for 242/243 and seem to suggest that on fasteners smaller than 6mm or 1/4" Loctite 222 (low strength) could be used.
I hope this info helps.

Mike

Well, Dave, if I had seen this yesterday, I would have been forced to reply with something along the lines of:

"Dave, obviously the 242 threadlocker must ONLY be used on metric threads, while 243 is restricted to SAE threading... APRIL FOOLS!

Luckily, I didn't see this post till today, and am able to keep from having to expose my silly side ;~D

Bryan