Thread-locker, most commonly known by the Loctite® brand name, is a lot like a Dremel® tool: if you have it, you feel an almost overpowering urge to use it - a lot. "But wait," say Brownells Gun Techs Caleb and Steve, "go easy with the Loctite on your AR-15!" It should NOT be used where steel and aluminum parts are threaded together. The steel is hard and the Loctite, when compressed into the threads, is also hard. The softest material in this equation is the aluminum... and you run the risk of stripping the threads on the aluminum part. So DO NOT use Loctite on the castle nut / buffer tube connection or the pistol grip screw. (Some aftermarket AR-15 pistol grips DO come with material to put on the grip screw, but it's not Loctite.) What about the barrel nut threads? Nope, says Caleb, Loctite is not a replacement for applying proper torque to that nut. Muzzle devices get so hot that Loctite won't be able to do its job on them. Instead, use Rocksett™, which can handle temps up to 1,300 deg. F. Some manufacturers of low-profile gas blocks do recommend a dab o' Loctite on the setscrews, but again it's a high-heat area, so there's little-to-no benefit. Bottom line: Loctite is a great product... Just don't use it on your AR-15.
VIDEO HERE (6:29 minutes)
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I don't know if it's just me but I always thought it was common sense to not use Loctite when assembling two metals of different hardness, but apparently there's people out there that do just that.
There are people that are wearing masks by themselves outdoors with no one around. of course goobers are going to put loctite on two metals of different hardness. thanks for the post. ~tonare
ReplyDeleteWell the makers of my KTM motorcycles specify it in just that combination, aluminum then steel bolts and screws. Look even with the loctite and the proper torque, shit still works its way out! Well they are off road racing machines. Not that Im claiming to be an off-road racer or anything of the sorts!
ReplyDeleteYeah, I read that part and cringed. There's Loctite and there's Loctite. Lower-grades of the stuff are fine to use steel to aluminum. I wouldn't use Red, and I've seen Green remove aluminum before. The lower-strength stuff like Blue should be totally fine.
DeleteThe blue lip-stick applicator is all I use now on my bikes. (KTM, Husqvarna, Gas Gas, Yamaha). Great stuff.
DeleteI never saw one of my armorers with any loctite in there boxes. These are school trained, Army School trained armorers. I had a few units in my time in the Cavalry, and we gots lots of guns.
Cavguy
Loose all Loctite.
ReplyDeleteIt’s not needed. Even on scope mounts.
Just clean all parts and torque to spec.
Ok, do as you see fit
"Loose" - The screw is loose and could fall out.
Delete"Lose" - If that happens, you could lose the screw.
glue the bolt shut and throw it in a lake
ReplyDeletego buy a real gun
Also choose your Loctite product with care. The mechanical engineering department where I used to work found out the hard way that Loctite Superglue is not a suitable substitute for Loctite Threadlock. I don't think they ever got those screws out again.
ReplyDeleteEvery commercial airplane in the world uses loctite on dissimilar metals and hardness, not in all applications but, enough.
ReplyDeleteThere's a bazillion different types of Loctite. Some are manufactured to use with dissimilar metals. I don't use any of it on an AR.
DeleteOne important step if you do use a threadlocker: degrease everything first. Non-chlor brake cleaner works well, let it evaporate completely before application of the threadlocker. Use the proper threadlocker, of course.
ReplyDeleteThe ONLY place I used LocTite on my ARs is ffor the scope and rings for the Picatinny rail.
ReplyDeleteI've been a machinist for 25 years in automotive, military, oil and gas to name a few. I've seen people, companies, even industry standards where loctite was used inappropriately. I hate having to heat something up to get the loctite to liquify so I can loosen it. The abundance of cheap chinese hardware doesn't help matters either. I only use it when I don't ever want the hardware to come out.
ReplyDeleteLots of good thoughts and opinions on this thread.
ReplyDeleteMy two cents- Clean your parts and use the proper threadlocker on what you're assembling. It's not rocket science, but then to the mechanically declined everything is rocket science.
-Elmo
It's fairly common for accuracy gunsmiths (as opposed to gun-smites camped out in the back of the pawn shop) who have a genuine track record for building super accurate AR-15's to glue the barrel/barrel extension assembly into the receiver, and let it dry before torqueing on the barrel nut. Using the proper adhesive and the correct assembly techniques, of course. Not necessary for the typical AR but if you want to win or at least do well at the national and regional level, you aren't a typical shooter using a typical rifle built or cobbled together by the typical gun plumber.
ReplyDeleteSince when did "Lose" become "Loose"?
ReplyDeleteSince they're vocabulary changed too decades ago, their very bad spellers, to.
DeleteMidwayusa.com is going to have to revise their AR build videos as Potterfield says to use loctite on the pistol grip screw and the buffer tube threads.
ReplyDeleteI use a combination thread locker / anti-seize compound.
ReplyDeleteType of bolt is an issue too.
ReplyDeleteLot easier to break a Loctite seal with an allen-head bolt than most others.