The wild card is that none of these should be solid joints (Arisaka's new mount not withstanding, or the bottom bolts in LT rings), so tube compression also comes into play. That is actually what keeps screws from backing out of these joints without loctite.
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Wet Mounting Scope Mounts - Where It All Started
- Thread starter matt2143
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It's a pretty well researched and understood relationship between friction and axial torque measurement vs compression/stretch, as well as the "slip and grip" nature of dry planar surfaces involved therein.
Wet mating or Couple lubing sounds good
Funny, that same training in basic college engineering courses and as a machining QA are why I've only ever wet mounted rings without knowing any of this, it just made sense at the time... wild.
If my rail and mount were coated in one of those self-lubricating coatings like NP3 would this still be a concern?
-Stan
-Stan
What?Yes I’m aware, but most non-QD mounts also have torque specs for the pic rail.
I don't think it would hurt to lightly oil the clamping surfaces. I've never had any issues but I don't think I've ever gone out of my way to degrease past wiping down new parts. It makes sense about the rough, dry surfaces not seating fully at first and then shifting. It's kind of like having to retorque lug nuts after mounting a wheel.
It reduces it, but it's still higher than steel/steel depending on the anodized surface. Lubricate threads and under the screw cap for even clamping force when using axial torque to approximate bolt stretch and joint compression
From an Engineering perspective, a torque value is used really to protect the bolt from yielding or the head from being turned off.
As soon as the clamping surfaces mate, there is a limit to the forces applied no matter how high you torque the bolt.
The caution when using a rail is to always seat the mount with forward pressure to the rail to insure proper surface mating.
Whether lubricating the surfaces stops movement from later impacts does not have any objective testing that I could find on-line.
But the admonishment has always to degrease because lubrication can change the mating forces Ie slip.
I will continue to use the mounting procedure I have used for decades.
The procedure works for me and I understand it.
Applying a lubricant, I don't understand?
-Richard
As soon as the clamping surfaces mate, there is a limit to the forces applied no matter how high you torque the bolt.
The caution when using a rail is to always seat the mount with forward pressure to the rail to insure proper surface mating.
Whether lubricating the surfaces stops movement from later impacts does not have any objective testing that I could find on-line.
But the admonishment has always to degrease because lubrication can change the mating forces Ie slip.
I will continue to use the mounting procedure I have used for decades.
The procedure works for me and I understand it.
Applying a lubricant, I don't understand?
-Richard
Easy to explain
Push your car on flat ground with 4 inflated tires, now try it with one flat, that is in basic terms, friction.
I can't recall call a time I have ever assembled an engine, gas or diesel, torqued or stretch to yield, studs or bolts, I haven't used some form of lubricant on the fastener, except for the 4100 Cadillac, 3/8" impact on the small stuff, 1/2" impact on the big stuff, it's not going to run long enough to matter, I hated those turds.
Push your car on flat ground with 4 inflated tires, now try it with one flat, that is in basic terms, friction.
I can't recall call a time I have ever assembled an engine, gas or diesel, torqued or stretch to yield, studs or bolts, I haven't used some form of lubricant on the fastener, except for the 4100 Cadillac, 3/8" impact on the small stuff, 1/2" impact on the big stuff, it's not going to run long enough to matter, I hated those turds.
No one is talking about back and forth movement. The forward pressure isn't for, "proper surface mating." It's because the rifle recoils in reverse. You want the recoil lug butted up against something solid, in the opposite direction. If your rail and clamp geometry are correct, and you lube the clamping areas so they seat properly at the directed torque, you don't even need a recoil lug.
How do you know your method is more consistent? Do you have torque/angle data on thousands of rundowns? Or better yet tension measurements?
Because I did when I worked at a Honda supplier programming and monitoring an entire line of DC nutrunners tightening thousands of joints a day, dry.
Did you measure bolt stretch? How did you quantify that the tension was indeed equal? Dry on dry threads will result in un-equal torque across fasteners.
The relationship between torque and tension is stabilized by lubricating the threads.
Why Do We Lubricate Threaded Fasteners? | Reliability Solutions
Understand the importance of lubricating threaded fasteners in our insightful article. Discover the role of lubrication in ensuring equipment reliability.
reliabilitysolutions.net
The Importance of Using Thread Lubricants in Bolted Connections
In any industrial plant, there can be thousands of bolted connections, primarily in the flanged connections throughout piping systems, on packed stuffing boxes on pumps and valves, and on heat exchanger covers, for example.
There is a preponderance of data suggesting strongly that lubricated threads produce a more consistent relationship between torque and tension.
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I've made it a habit to push my rings/mounts forward into the pic rails, and then apply blue Loctite to every screw before torquing down in a star pattern. I am sure that there are methods out there that may provide better results...but I'm not experiencing zero shift in my rifles. Bear in mind that these aren't necessarily dedicated hard-use rigs, but many of them are going to ride around a ranch in a SxS and get bumped around a lot more than rifles that are just taken to the range and back. Still no zero shift.
I've never been one to marry myself to an idea regarding any shooting sport. There are always going to be new innovations or ideas that can further the shooter and equipment coming along. However, I don't see the need here for guys like me to strip their equipment down and start the mounting over, just because a few tests said that it was better. I may try this wet method though on my next rifle and see if I like what it is giving me...what can it hurt?
If what you are doing works, no need to change. Why argue over it?
I've never been one to marry myself to an idea regarding any shooting sport. There are always going to be new innovations or ideas that can further the shooter and equipment coming along. However, I don't see the need here for guys like me to strip their equipment down and start the mounting over, just because a few tests said that it was better. I may try this wet method though on my next rifle and see if I like what it is giving me...what can it hurt?
If what you are doing works, no need to change. Why argue over it?
ive posted this in past threads on this, but ive tested lubed rail vs not a few different ways
if youre the type to set the rings on the rail, apply forward pressure to seat the recoil lug and just start tightening the screws...depending on how much play the clamp piece has with the screw holes/rail/etc and how well it naturally aligns...youre more likely to see issues with shifts. this is how/where i saw issues when they occured for me
if you set your rings on the rail, apply forward pressure to seat the lug, and then also take care to physically align/settle/seat the clamp pieces before you begin the torque the screws, youre less likely to see any issues...in fact, i cant recall ever seeing a shift when i did this with the various rings and mounts i had at the time. on some ring/mount designs seating and holding the clamp piece while torquing the screws is harder (more awkward) to do than others
so IMO pick one...lube it and screw it...or take care to align/seat all mating surfaces and then torque
again not, lab tested.....but i found what i needed to be reliable for me and went with it...no issues ive seen since, lots of rifles and scopes
if youre the type to set the rings on the rail, apply forward pressure to seat the recoil lug and just start tightening the screws...depending on how much play the clamp piece has with the screw holes/rail/etc and how well it naturally aligns...youre more likely to see issues with shifts. this is how/where i saw issues when they occured for me
if you set your rings on the rail, apply forward pressure to seat the lug, and then also take care to physically align/settle/seat the clamp pieces before you begin the torque the screws, youre less likely to see any issues...in fact, i cant recall ever seeing a shift when i did this with the various rings and mounts i had at the time. on some ring/mount designs seating and holding the clamp piece while torquing the screws is harder (more awkward) to do than others
so IMO pick one...lube it and screw it...or take care to align/seat all mating surfaces and then torque
again not, lab tested.....but i found what i needed to be reliable for me and went with it...no issues ive seen since, lots of rifles and scopes
I accumulated thousands of rundown (torque and angle) traces using Cooper and Atlas Copco DC nutrunners on dry threaded joints. That data had to be analyzed on a very frequent basis for both conformance to specs and for process capability and reviewed with the customer (Honda).Did you measure bolt stretch? How did you quantify that the tension was indeed equal? Dry on dry threads will result in un-equal torque across fasteners.
The relationship between torque and tension is stabilized by lubricating the threads.
Why Do We Lubricate Threaded Fasteners? | Reliability Solutions
Understand the importance of lubricating threaded fasteners in our insightful article. Discover the role of lubrication in ensuring equipment reliability.
The Importance of Using Thread Lubricants in Bolted Connections
In any industrial plant, there can be thousands of bolted connections, primarily in the flanged connections throughout piping systems, on packed stuffing boxes on pumps and valves, and on heat exchanger covers, for example.www.pumpsandsystems.com
View attachment 8604110
There is a preponderance of data suggesting strongly that lubricated threads produce a more consistent relationship between torque and tension.
That volume of real data, not copy and paste internet articles, is what tells me that your absolute statements aren't as absolute as you think.
The torque/tension relationship isn't more consistent when the joint is lubricated. It's just a different slope to the linear region and a usually a more abrupt start to the linear region of the relationship.
I’m not a physician, but that whole “first, do no harm” thing makes a lot of sense to me. With that in mind, I’ll not be tearing down rifle/mount combos that are working without issue. But, when mounting a new optic, I don’t see the harm in this whole wet mount craze. I mounted an optic to a rifle today, and added a bit of lube between the rail and the mount. Do I expect to notice a difference? Not really. But, maybe I’ll see a reduction in those occasional, small, day to day zero fluctuations.
This is how I imagine @BurtG ’s hands when working on his various rifles:
(Not doctored, see vids)
Phuking sausage-fingered savage, he is.
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