The merits of thread-lock

Miki

Well-Known Member
Following on from a thread that I thought was about thread-lock but wasn't ...

Threadlocking isn't always neccessary and depends upon the thread interface and the amount of force/vibration that the two items are experiencing.

There are different types of threadlock compound available all of which are anaerobic adehisves that cure/harden in the absence of oxygen. Essentially they are similar to superglue which forms a fine grained plastic substrate that binds into the pores of the metal. There is a lot of info on the Loctiite web pages.
Locktite 222 (purple) is (in my opinion) all you should need to ensure an interference fit between (for example) a weaver rail set screw and the action. Scope rings shouldn't need anything unless they are worn or missaligned/missmatched.

The only other time you should need to apply this type of locker is if the two threads are somehow missmatched. Tyically a thread is cut into the action (for example) and typically the threads are rolled onto the set screws/bolts.
There is a specification relating to screws and theads which offers a tollerance/gap between to two. This is where quality and cost meet, it's much cheaper to roll a thread than cut it and fine, matched tollerance costs more.

Threads stretch too and this is why a torque wrench is reccommended, over tighten a screw and it will not form as tight a bond (into the thread) as it did when first fitted. Repeapeatedly tightening and loosening reduces the clamping force between the two threads and vibration (lateral or torsional force) will loosen it. Applying a bonding substrate (ie locktite) between the two threads will lock them tightly together (like it says on the tin).
Chosing the right 'glue' is important as some (Red locktight for example) are not designed to be dissasembled unless ithe material is heated to above 280 degrees C
 

ejg

Well-Known Member
miki, at a certain point thread lock becomes a lubricant. Stainless on stainless threadlock helps avoid galling on closing as well as opening. On steel screws threadlock keeps moisture out and avoids corrosion. Dampens vibration which helps avoid loosening.
edi
 

Miki

Well-Known Member
every day is a school day :)

I understood that Locktite was a single-component adhesives that cures in the absence of air and in contact with an active metal forming a thermoset plastic, which fills the void between the male and female threads. I know you should use a primer with innactive metals (stainless, titanium, silevr, zinc etc)for a permanent fixing, but never knew it as a lubricant. The 'new' blue 243 locktite can also be used on innactive metals but I would still reccommend only 222 (purple) on and around guns as it holds fast and 'breaks' without excessive force (ie you wont strip the head off an M3 allen bolt/set screw).
 

Gm81

Well-Known Member
222 for the win. We used to use it on the bolts holdingcthe wires on common rail injectors. So they were tiny and just stopped vibration loosening. Can’t see a gun needing anything more permanent.
 

HistoricBore

Active Member
Just yesterday, after our annual social clay shooting session, I found that the screw holding the top lever in place on my old Webley sxs had come loose. So I wiped off quite a lot of oil from the thread and then put a spot of Hermitite Nutlock on it. We will see if that does the trick, but I don't want to lose that hand-made screw out in the field....

HB
 

McKenzie

Well-Known Member
Just about to investigate having it done to the screws that hold the hammers in place on my P.Webley hammer gun. I don't use it much but it's alarming how quickly they work loose.
 

fizzbangwhallop

Well-Known Member
Loctite variations....purposes and characteristics

Just read this thread and went sideways out of interest to look for 222 and found this seller with a description of each type of loctite....might be useful to somebody


Ok, it’s probably on the loctite website but I can’t be ached to go and look :rofl:

Cheers

Fizz
 

CarlW

Well-Known Member
Loctite variations....purposes and characteristics

Just read this thread and went sideways out of interest to look for 222 and found this seller with a description of each type of loctite....might be useful to somebody


Ok, it’s probably on the loctite website but I can’t be ached to go and look :rofl:

Cheers

Fizz
This might make me sound mental, but I now feel the need to own the whole suite of them...all lined up...in little rows...ready for all thread eventualities...
 

Miki

Well-Known Member
This might make me sound mental, but I now feel the need to own the whole suite of them...all lined up...in little rows...ready for all thread eventualities...
Me too, and at the end you'll need a UV torch so you can see it fluoresce ...
 

Top