Does Loctite alter torque on scope rings

[Lentuk]

I have been told by Warne customer service that using blue loctite on my scope rings caused over torquing and is the reason the Warne Hyperlite rings damaged my Trijucon Accupoint.
I used a Wheeler fat wrench set at 15 inch pounds and this is the result.

 

[83cj-7]

Yes, it does change the torque. So will oil or anything else. I always make sure the screws and threads are clean and dry. Sometimes I have to use break cleaner. If I want to lock the screws, I put a drop of clear fingernail polish on the heads once it’s torqued.

 

[Weldor]

I don't know if there is a wet torque chart , probably is somewhere on the interweb. It would be wise to compare dry torque to wet torque on small screws and such. I don't have access to it anymore , but we used to use a torque plate to certify our torque wrenchs. Would be nice to have one made for inch pounds for sure.

 

[ThorM465]

Technically, yes it does. Wet torque vs dry torque. Figure out what size bolts you have and you should be able to find these 2 different torque specs online. That being said, it shouldn't be enough to make a noticeable difference. It's much more likely that your torque wrench isn't accurate or you used cheap chinese rings or both.

 

[Lentuk]

Brand new Warne USA made Hyperlite rings and a Wheeler fat max torque wrench that I have used dozen of times with no other problems.
I just talked to Trijicon, they rate their scope tubes at 18 inch pounds.
Even if the Fat Max is off 5 inch pounds it should not have dented the tube, something is up with these rings.
Trijicon CS also said they use blue Loctite on all the rings they use.

 

[ScreamingPotato]

Wow that's pretty extreme, I can't imagine 15 inch lbs doing that no matter how lubed it was.

 

[Lentuk]

The 30mm ones are small also, these are old TPS 30mm rings compared to the Hyperlites.

 

[ScreamingPotato]

^I don't think that measurement is relevant since there should be a gap in the rings when torqued correctly. Might measure side to side?

 

[Lentuk]

Already sent the scope and rings back to Warne. They are going to look at it.
This is really more about the loctite, they are claiming it was the culprit.

 

[nighthawkf-117]

I can't really see how loctite could cause that big a discrepancy in torque. It almost looks like the rings are not concentric and undersized. In your photo measuring the rings you can see where the coating on the rings was discolored from the contact with the scope tube. This appears to be a small contact area. If the rings only contacted on a portion of the scope tube it would cause all of the torque from the screws to concentrate in that small area, vs spread out across the whole ring surface.

 

[Lentuk]

^ That is what I think also. The 30mm rings were mounted on another trijicon, the rear ring was close to the power adjustment ring, when I torqued them to 15 inch pounds they locked up the adjustment ring, the TPS ones did not.

 

[Marbles]

Looks like undersized ring top halfs to me. Regardless of what Warne says, I will steer clear of their rings (unless they replace rings and scope).

 

[journeyman713]

The rings were good, still are.
The problem was over torquing. You used the dry torque rating, on a wet torque application.
The difference is the added lubrication really increases the force on the screw at the same torque. Without reducing the torque for a lubricated screw, you could easily hit the yield strength of the screw, or create a problem like you have.
The screws are junk now btw.

 

[journeyman713]

After relooking at the photo, it appears the assembly sequence was sloppy.
The gaps should have been snug and equal on each side, then a gradual Cris-cross tightening.
Tough lesson learned.

 

[TaperPin]

That sucks, but luckily minor denting won’t hurt anything. Weird - sounds like you put more of an effort in than most.

It seems like thread lockers increase clamping force something like 20% over dry threads, or something like that. I wouldn’t think it would make a big difference.

It could be stacking of minor errors. The tube is slightly thin, the torque wrench reads slightly under, the ring design bends into the tube slightly more than average, slightly more torque with thread locker.

Checking the torque wrench with another torque wrench is probably a good idea - I bet lunch the Wheeler is off.

 

[Macintosh]

Sure, wet will have slightly higher torque compared to dry. But out of the box their ligjtly oiled screws arent dry either. But even 30% higher than 15inlb is only 19.5inlb…how much do they claim the loctite will
Increase torque?? 19.5inlb is still less than tons of people use for their scopes to begin with. I use 20inlb often, ime 15inlb is not sufficient most of the time. Im not aware of any ring manufacturer recommending no more than 15inlb any longer…What is warne’s torque recommendation? And if the additional 3-5 inlb is so critical why do they supply a simple allen key with their rings rather than insist they be torqued?

Edit: also this thread is recent and has some info from various manufacturers as well as some entertainment value. Several posts (164, 318, 320 and others) detail various scope manufacturers explicitly saying the reason they recommend against loctite is because customers get blue crap on their threads and then complain, NOT for any functional reason. It seems warne is in the minority in taking a hard line on this. Which is doubly interesting considering that their vertical split rings have a well-known reputation for damaging scopes.

Scope mounting loctite or not?

Liberals are blue... Always go red! As a user of Purple loctite for most small fasteners, lol

rokslide.com

 

[Marbles]

The rings were good, still are.
The problem was over torquing. You used the dry torque rating, on a wet torque application.
The difference is the added lubrication really increases the force on the screw at the same torque. Without reducing the torque for a lubricated screw, you could easily hit the yield strength of the screw, or create a problem like you have.
The screws are junk now btw.

Locktite is not oil. I am doubtful that even oil would meaningfully alter the K value enough to have a meaning effect on torque.

Unless Warne can specify the wet torque, they are spewing BS and have not conducted the necessary laboratory testing to know their answer is valid.

 

[TxxAgg]

No way loctite made any noticeable difference to cause that damage. Something else is going on.

 

[Muleface]

I just talked to Trijicon, they rate their scope tubes at 18 inch pounds.

Sorry you got those dents.

This is weird for Trijicon to say. Converting between torque of a fastener and resultant pressure on a thing requires more information. 18 torque units on a screw with a lesser thread pitch will result in more pressure than will the same torque on a greater pitch fastener. It doesn't make sense to rate a tube for a fastener torque. You can get the same rail grip pressure from two low-pitch small screws as you do from a large tactical-style nut with coarser threads, but torque for the former is 25 in*lbs and 60 for the latter. Curly Howard would rather have his head in THIS vise with the coarse thread than in THAT vise with the fine thread, for a given vise-operating woman and handle length. How can Trijicon say they rate Curly's skull for a given woman?

Weird for Warne to blame it so quickly on Loctite. I guess that's straightforward though. Did you tighten gradually and evenly? I've dented by not tightening gradually and evenly, using totally fine equipment and correct torque. "Tough lesson learned," as was said by @journeyman713

I don't know if this is news to anyone here, but: establish level by snugging one (say, rear) ring with other (front) loose, then carefully get the front evenly clamped (feeler gauges on gaps if you're like that) while the rear is holding the tube. Tighten front ring fasteners in whatever cross pattern the number of them requires, in tedious quarter-turns so that the thing really stays even -- goal is no tipping of the ring half relative to the other half during tightening because that's what makes dents and burnishes anodization. Then loosen the rear one, position the top ring half evenly, and tighten evenly. If you're "like that," you can again do one more loosen/set on the front one to ensure the ring pair is not exerting any torsion on the tube. I bet tubes can take a lot of torsion and it probably doesn't matter! But doing it this way means no dents.

 

[JohnJohnson]

The rings were good, still are.
The problem was over torquing. You used the dry torque rating, on a wet torque application.
The difference is the added lubrication really increases the force on the screw at the same torque. Without reducing the torque for a lubricated screw, you could easily hit the yield strength of the screw, or create a problem like you have.
The screws are junk now btw.

I've seen a lot of mixed feedback on whether this is actually true or fuddlore. Any sources for how much the loctite would increase the K value?