Conflicting torque specs

[Hunter 08]

Earlier this year, I picked up a Vortex Venom 3-15x44 first focal plane scope on sale. Didn't come with a mount and waited a while to pick one up. Ordered a 34mm cantilever mount from Midwest Industries. However the scope says do not torque beyond 18in/lbs. But the mount says torque to 20-25in/lbs.

So do I follow the torque spec from Vortex or do I use the one from Midwest Industries?

 

[ColtPythonElite]

If I had to pick a number, I'd go with 18 on the scope ring clamps. Fortunately, I don't ever face that dilemma, because I don't use a torque wrench when mounting scopes.

 

[Hunter 08]

If I had to pick a number, I'd go with 18 on the scope ring clamps. Fortunately, I don't ever face that dilemma, because I don't use a torque wrench when mounting scopes.

Kind of what I was leaning towards but wanted to get an opinion. Picked up a Wheeler torque set for Black Friday but it starts at 15in/lbs

 

[Varminterror]

18

 

[Walkalong]

Yep, go with what Vortex says.

That said, the difference between those two numbers is small, and a lot of common torque wrenches are +/- 4%.

I do use torque wrenches.

It is extremely hard to hit 18, 20, 25, etc inch pounds by feel. If anyone doesn't believe that,
go buy a torque wrench, do a bunch of fasteners by feel, then check yourself.

 

[Hunter 08]

Yep, go with what Vortex says.

That said, the difference between those two numbers is small, and a lot of common torque wrenches are +/- 4%.

I do use torque wrenches.

It is extremely hard to hit 18, 20, 25, etc inch pounds by feel. If anyone doesn't believe that,
go buy a torque wrench, do a bunch of fasteners by feel, then check yourself.

I work in automotive as a technician. Use torque wrenches a LOT. Inch pounds is minuscule. Even when something is like 89in/lbs it feels like a bit beyond finger tight and not much more than that, something cracks or strips out or both.

 

[Walkalong]

I work in automotive as a technician. Use torque wrenches a LOT. Inch pounds is minuscule. Even when something is like 89in/lbs it feels like a bit beyond finger tight and not much more than that, something cracks or strips out or both.

I've used tools all of my life, and the first thing I learned when I got inch pound torque wrenches for scopes was that I was over tightening things.

 

[snowman357]

go with lower number and see if everything is good, if not go with the higher number.

 

[RetiredUSNChief]

If you're torquing fasteners in the in-lb range, and they've got split washers for lock washers, pretty much all you need to do is tighten just enough to compress the split washer and no more.

If they don't have split washers to judge by, then you're very likely going to over torque the fasteners without a torque wrench.

Occasionally I have need to torque things to 5 in-lbs. We've some engineers who found out what kind of damage you can cause by not using a torque driver for those screws.

 

[Shawn Dodson]

When in doubt, use the lower torque value.

Use a torque screwdriver instead of a snap-action torque wrench for fasteners with a low torque value.

The handle on a torque screwdriver free-spins when the torque value is reached and you can't over-torque.

Whereas a the "snap" of a snap action torque wrench set at a low torque value may not be sensed by the operator, which usually leads to applying too much torque and possible damage.

 

[7mmRLC]

All Vortex scope I've seen and mounted use a 16 -18 in lbs. I had a scope sent back to them for excessive parallax. When they replaced it they sent a notice that I had over torqued the scope rings and not to go beyond 18 in lbs. I do believe I used 20 in lbs that time.

 

[Walkalong]

When in doubt, use the lower torque value.

Use a torque screwdriver instead of a snap-action torque wrench for fasteners with a low torque value.

The handle on a torque screwdriver free-spins when the torque value is reached and you can't over-torque.

Whereas a the "snap" of a snap action torque wrench set at a low torque value may not be sensed by the operator, which usually leads to applying too much torque and possible damage.

Along those lines, I would suggest not using a 10 to 150 inch pound torque wrench for 18 inLb screws, use one along the lines of 10 to 50 etc.

I like this screwdriver type for cap screws, easy to read, easy to use, but I am just as comfortable using a low inLb wrench type.

For torquing the rings to the rail I use this wrench, easy to read, very positive break when it reaches the torque setting. The Sunex I linked to used to be a lot cheaper,
and while in the picture it looks easy to read, in real life I have to use a magnifier, which is why I ended up with white on black and yellow on black wrenches.

 

[243winxb]

torque

Back in the dark ages, turned screws as tight as possible with a screw driver. Except for Redfield windage adjustment screws. Early one would snap off.

Keep the rings out of the red area.

 

[irishlad]

Along those lines, I would suggest not using a 10 to 150 inch pound torque wrench for 18 inLb screws, use one along the lines of 10 to 50 etc.

I like this screwdriver type for cap screws, easy to read, easy to use,

I use the same one, just says Vortex on it. Works well.

 

[Hunter 08]

This is the set I picked up recently https://www.wheelertools.com/fat-wr...VPLYWV_HUob3S-sZMTUooWsBoCOQIQAvD_BwE&start=1

 

[RetiredUSNChief]

Speaking of torque problems...

I once had to drive to the naval base from the shipyard on a weekend to assist in a temporary repair to a grounded cable on a submarine so they could get underway the following Monday.

It was a simple fix, Ship's Force doing the work with material I supplied.

When they were done, they were just going to tighten the stud hardware with wrenches and be done with it.

"No, no, no...there are torque specs on this bronze hardware because they're high current power connections. Let me show you in the tech manual."

So they got a calibrated, bi-directional torque wrench of the correct range (I verified this). While the petty officer was torquing the hardware, I was discussing something about the permanent repairs to be done when they got back from sea.

I heard a "tic-tic-tic" of something metallic hitting the deck. I looked down and saw a broken bronze stud next to my foot.

The Engineer, Chief, and petty officer looked.

I said "let me see the torque wrench, please".

I looked at the bi-directional dial indicator.

The petty officer had turned the dial the wrong direction so the needle was resting on the wrong zero peg and wouldn't deflect in the clockwise torque direction.

He didn't see the needle move as he was tightening the nut on the stud and kept tightening until the stud broke off.

I said "Well, not getting underway Monday. The broken stud can be replaced, which requires the transformer to be removed, but we don't have that part and would have to research and order it. Probably faster to just replace the entire transformer. I believe you have a spare on board somewhere. Just an FYI...the transformer weighs approximately 500 pounds."


I was pretty impressed that there were no overt displays of anger. Very professional, I thought.


There are some things where I'm not too concerned about actually using a torque wrench. Like lug nuts or common bracket mounting hardware. Other things you're stupid not to use a torque wrench.

Know the difference and know how to properly use the tools.

 

[CowboyTim]

Company I work for has done most of the concrete for Vortex's main office/production/distribution complex.

I've had the chance to talk to a couple of the guys who work with returns. I was told that something around 90% of returns were just overtorqued and that 18lbs was PLENTY to hold an optic in good rings.

 

[kmw1954]

Not unusual response from the manufacturer.

Recently talked on the phone with a CS rep for Athlon Optics regarding an issue I was having. One of the very first question he asked was what were the torque values I used on the rings. I told him I believed it was 25in-lb. Which he then replies that the tube was probably crushed or distorted. Again they also stated that 18in-lb value.

I now tend to believe the manufacture of the optic advice. After all they know their product.

 

[General Geoff]

I've used tools all of my life, and the first thing I learned when I got inch pound torque wrenches for scopes was that I was over tightening things.

Just doing torque-to-yield!

 

[Hunter 08]

Not unusual response from the manufacturer.

Recently talked on the phone with a CS rep for Athlon Optics regarding an issue I was having. One of the very first question he asked was what were the torque values I used on the rings. I told him I believed it was 25in-lb. Which he then replies that the tube was probably crushed or distorted. Again they also stated that 18in-lb value.

I now tend to believe the manufacture of the optic advice. After all they know their product.

It's kind of weird that the ring manufacturers aren't on the same page. I'd have to see if the Vortex rings I have if they said 18in/lbs or something else.

 

[12Bravo20]

18 inch pounds is pretty much the standard for ring caps and 25 -30 inch pounds is the most common for the mount bolts when attaching to rails.

 

[RetiredUSNChief]

Something I neglected to talk about, which is actually the answer to the OP's question.

In my line of work, if there are conflicts in torque values I'll gather all the source information for the various differing values.

From there, I'll look at the precedence of the source documents. The various drawings, technical manuals, and operating manuals have a specific order of precedence in my line of work.

Then I'll go speak with the mechanical engineering code(s) on the matter, to get their input.

Then I'll make some phone calls to some off-yard contacts to discuss this.

After that, I'll write off-yard correspondence (in the form of a "Trouble Record") which will detail the issue and findings. Typically, this will include a shipyard recommendation based on all the findings and a recommendation to accept this.

The Trouble Record is then processed through to the off-yard agencies which are cognizant over whatever systems are involved and an answer will be provided which either concurs with the recommendation or rejects the recommendation in favor of another solution.


This, my friends, is the reality of the world of Naval Nuclear Propulsion Program that I live and breathe.


In this world, however, the much simpler process is what others have said: "Call/write the manufacturer".


There's a lot more to torquing than the average layman understands. Wet torque, dry torque, running torque, torque multipliers, torque by comparison, bolt types and uses, hot torque, cold torque, structural purpose of the torque requirements, etc.

Torque values and methods are determined for a purpose. Improper torquing can have bad consequences, depending on the device/system. Wet torquing something that's designed to be dry torqued can result in overtorquing, for example.

The vast majority of common mechanical work around the house/garage probably isn't all that sensitive to incorrect torquing.

However, I assure you that you WILL want that engine you're rebuilding to follow the torquing requirements.

Sensitive/expensive components require due consideration. Which is why the initial post in this thread is such an excellent one. Nobody wants to damage an expensive scope over a seemingly trivial matter of a few in-lbs of torque.

 

[Laphroaig]

I recently purchased a Fix-it-stix torque wrench set as part of my Midway birthday deal, but haven't had a chance to use it yet. I know that I have damaged a cheap BSA scope by overtightening in conjunction with shims, but that wasn't much of a loss. I'm wondering if its possible to somehow damage rings by overtorquing like I have been doing?

 

[JFrank]

It's kind of weird that the ring manufacturers aren't on the same page. I'd have to see if the Vortex rings I have if they said 18in/lbs or something else.

I think the scope tube on the Vortex isn’t quite as robust as some other brands.

 

[Varminterror]

I'm wondering if its possible to somehow damage rings by overtorquing like I have been doing?

Much more likely to do damage to the scope tube than the rings themselves.