Does Loctite alter torque on scope rings

[JohnDough]

John, I mount an awful lot of scopes and haven't crushed a tube in at least 20 years. I figure if I can chamber a barrel and true up an action....mounting a scope should be within my capabilities.....but explaining it apparently isn't.

I love the internet.

I don't personally know anyone who HAS crushed a scope tube.

 

[MallardSX2]

Been using a fat wrench for years.

Blue loktite on the base threads and dry scope cap bolt threads.

I use the manufacturers recommended ring torque value and manufacturers base torque value and roll with that.

Never had an issue. Ever. And I hunt my ass off….and I’m pretty hard on things.

I don’t put nail polish on my ring cap bolts either…too ocd for that. Lol

 

[Sundodger]

I've seen loctite modify tension/compression/stretch, and I've seen it not. I think substrate materials are also a factor here.

I believe you. That's why a formal study is supposed to be done, if any of the affects are critical.

Information from some adhesive manufacturers can be misleading. Loctite may still advertise that their locker doesn't affect "torque" but their technical papers stated that a study should be done with and without locker to ensure proper joint connection.

Most of this is unlikely to matter for hunters and shooters. However, as a group, I would just prefer that we don't regurgitate bad information with blanket statements.

That's one of the things I enjoyed about bolted joints, it was an interesting combination of art and science. It is no doubt engineering you can model and make predictions on, but slight changes to materials, process, coatings, etc. can lead to drastically different results. Tons of this testing is conducted at OEM's every year, but they don't just go around publishing their IP.

Couple things I will mention that lead many people astray in this domain:

-Don't think of a torque to tension being a 1:1 relationship, as in if you hit X torque you will get Y tension. Think of it like a bell curve. If you hit X torque the tension lies somewhere on this bellcurve. Or better yet, if you don't have fancy production DC tools that's tq delivery is really precise, two compounding bellcurves one for tq and one for tension. Now you can set up all your virtual conditions.

-Friction will mislead you, it is the "noise" in the system. When you get to 75% proof load on a fastener almost all the tq that is being applied to the bolt is going to friction not tension. This means tiny changes in friction have massive impacts on tension, so there are red herrings everywhere. You need large samples sizes and OCD levels of diligence. Tq + angle is an effective option to battling friction if you have the bolt length.

-Mind your D to L ratio. Not enough bolt stretch will cause joint failures. This is one of the reasons we still use rivets, hucks, etc. today.

 

[IdahoBeav]

I stopped using loctite on rings and have never had a screw back out.