Torque Question (involving NF and Spuhr)

[RedBreast21]

Most people here are probably familiar with Spuhr mounts. 6 screws per "ring", and from 21-25 in-lb per screw. I have I 6-8 Spuhr mounts and have never had any issues (and shouldn't for what they cost). However, I recently picked one up (30mm, 1.89") and mounted a NF NX8 1-8 in it.

I mounted it as I always do, using a FixIt Sticks torque limiter, and started in the middle two screws on each ring to resistance/alternating and then torque to spec. Then I move to the outside 4 screws and do the X pattern alternating to resistance and then to torque. Here's where my question comes in . . . once you torque those outside screws the middle ones are now looser (obviously) and I continue to torque down until all 6 screws are limited by the limiter. Is the torque somehow additive? If it's tightened to 21 in/lb and then you go back over it again after it's been "loosened" by tightening the outside screws on the rings, does that mean it's now MORE than 21 in-lbs?

Now here's the why: after mounting the optic (at the range) and zooming into the targets at 500 yards, things were very, very blurry. I brought it home, set it upon my tripod and looked off my deck into the surrounding hills and confirmed that it wasn't some weird thing at the range. I emailed and then spoke to NF and they said "sure, send it back in", but then I started thinking. What if it's the mount? So, I took off the front "ring" and the image was clear again. I then completely removed the optic, made sure it was 100% centered (the turret housing relative to the rings) and retorqued the rings. The blurriness had returned.

So, I grabbed the a much lower torque limiter and tightened it down just to snug and the image is clear again.

Knowing what I know about NF, it's hard for me to believe there is anything wrong with the scope body such that it's out of round. But the same is true of Spuhr, too.

What are your thoughts? I always think I'm not an idiot, but I consistently prove myself wrong. I'm wondering if this is one of those times.

 

[Cutout]

I hope you mean "inch pounds" and not "foot pounds."

 

[Taylorbok]

I hope you mean "inch pounds" and not "foot pounds."

if he's using fix it sticks it's inch lbs.

I use MDT and ARC mount's. The MDT I go over the screws several times until they are all limited by the limiter and never had an issue. The ARC only has one bolt so it get's torqued once and then double checked. That ARC mount is tittie's BTW and don't think I'll buy anything else again.

 

[Arc Light]

The torque value is not additive, if you set it to 21 in-lbs that's what the screw will be torqued at, no matter how many times you go over the screw. If you lubed the threads and didn't reduce the torque by say 25%, then you'll get more clamping force vs dry threads and could cause damage to the scope or mount.

I've never used Spuhr mounts, but 21-25 in-lbs on the screws seems excessive to me. I've never used more than 15-18 in-lbs on dozens of rings and mounts and never had an issue with an optic moving. I would start at 15 in-lbs and see if the scope moves.

 

[Cutout]

 

[RedBreast21]

I hope you mean "inch pounds" and not "foot pounds."

Yes, lol. I'm so used to typing "FPS". I just edited to clarify.

 

[Cutout]

Yes, lol. I'm so used to typing "FPS". I just edited to clarify.

Lol, I get it. Just making sure.

 

[RedBreast21]

The torque value is not additive, if you set it to 21 in-lbs that's what the screw will be torqued at, no matter how many times you go over the screw. If you lubed the threads and didn't reduce the torque by say 25%, then you'll get more clamping force vs dry threads and could cause damage to the scope or mount.

I've never used Spuhr mounts, but 21-25 in-lbs on the screws seems excessive to me. I've never used more than 15-18 in-lbs on dozens of rings and mounts and never had an issue with an optic moving. I would start at 15 in-lbs and see if the scope moves.

I did not lube. As @Cutout noted, Spuhr calls for 15-25 INCH/lbs.

 

[koshkin]

Conical head screws in Spuhr mounts occasionally werak havoc on optics. They pull the ring halves laterally when the machining is not perfect. That creates shear stress on the scope tube. Most of the time Spuhr mounts work fine, but as far as expensive mounts go, I have seen more problems with Spuhr mounts that with all the rest combined and not by a small margin.

ILya

 

[1911hombre]

Didn't it used to be that Spuhr wanted the user to apply rosin on the scope tube "if you encountered slippage" or some shit?? Or maybe a chunk of beer can shim, I forget. Oh, and if the threads strip, just go ahead and use the next bigger self-tapping screw. FFS. I like good mounts but Spuhr seems so.... Diva. I also believe the conical head screws by virtue of that design are inconsistent in regards to stretch vs. observed torque, which may be the root of some of their problems.

 

[hafejd30]

My 7-35 atacr is torqued to 25 in lbs in my spuhr with blue loctite. No issues with the rings or scope

When the crossbar on the pic rail cracked I wasn’t happy. But the new one has been mounted several times and is still in one piece

The NX8 may be a thinner tube. Try 15-18 lbs.

 

[chevy_man]

It still baffles me people pay spur money only to get a sub par product. The number of products that are half the price and have fewer issues, spur has great marketing!

 

[MechanicGino]

Most people here are probably familiar with Spuhr mounts. 6 screws per "ring", and from 21-25 in-lb per screw. I have I 6-8 Spuhr mounts and have never had any issues (and shouldn't for what they cost). However, I recently picked one up (30mm, 1.89") and mounted a NF NX8 1-8 in it.

I mounted it as I always do, using a FixIt Sticks torque limiter, and started in the middle two screws on each ring to resistance/alternating and then torque to spec. Then I move to the outside 4 screws and do the X pattern alternating to resistance and then to torque. Here's where my question comes in . . . once you torque those outside screws the middle ones are now looser (obviously) and I continue to torque down until all 6 screws are limited by the limiter. Is the torque somehow additive? If it's tightened to 21 in/lb and then you go back over it again after it's been "loosened" by tightening the outside screws on the rings, does that mean it's now MORE than 21 in-lbs?

Now here's the why: after mounting the optic (at the range) and zooming into the targets at 500 yards, things were very, very blurry. I brought it home, set it upon my tripod and looked off my deck into the surrounding hills and confirmed that it wasn't some weird thing at the range. I emailed and then spoke to NF and they said "sure, send it back in", but then I started thinking. What if it's the mount? So, I took off the front "ring" and the image was clear again. I then completely removed the optic, made sure it was 100% centered (the turret housing relative to the rings) and retorqued the rings. The blurriness had returned.

So, I grabbed the a much lower torque limiter and tightened it down just to snug and the image is clear again.

Knowing what I know about NF, it's hard for me to believe there is anything wrong with the scope body such that it's out of round. But the same is true of Spuhr, too.

What are your thoughts? I always think I'm not an idiot, but I consistently prove myself wrong. I'm wondering if this is one of those times.

We have similar issue in my friend rifle. He use to cheap torque wrench and possible over torqued, Mess it up to vortex razor scope. That issue, article doesn't move when shifting elevation/windage knobs. Sounds like scope body shrink/bend. But, vortex report to over torque issue and charge only $220 fee. When scope returned, perfectly operate. My opinion, vortex torque screwdriver it's a real tool. Use to least 100 times and checked calibration few times, always in tolerance specs.

 

[Rob01]

We have similar issue in my friend rifle. He use to cheap torque wrench and possible over torqued, Mess it up to vortex razor scope. That issue, article doesn't move when shifting elevation/windage knobs. Sounds like scope body shrink/bend. But, vortex report to over torque issue and charge only $220 fee. When scope returned, perfectly operate. My opinion, vortex torque screwdriver it's a real tool. Use to least 100 times and checked calibration few times, always in tolerance specs.

Vortex charged you $220?!? For what? They have a VIP warranty and it should have been fixed for free.

 

[MechanicGino]

Long story, some how serial number not visible. Possible reason to charge that amount. My razor gen3 happen turret issue, new scope elevation turned very hard and tight. I send it back and 2 weeks later received other new scope. Is it Vortex warranty, no question!

 

[Holliday]

Vortex charged you $220?!? For what? They have a VIP warranty and it should have been fixed for free.

I have never heard of Vortex charging a warranty fee…..

 

[Nik H]

I use SPUHR and NF. My 7-35 / SPUHR mount's rings are torqued at 18-inch pounds. After all the screws are inserted and finger tightened, I check the rings to ensure that the gaps are the same on each side. I don't torque to full value at once. I use an X pattern for the corners and then do the middle screws. I finally torque the corner screws, and then the middle screws to 18-inch pounds. Check the gap and off to the range for final alignment in position and tall target.

There are no issues and no slippage either.

 

[1911hombre]

I have never heard of Vortex charging a warranty fee…..

That's cuz they don't. Maybe it was just a language barrier. Two Pinocchios on that one.

 

[Holliday]

What I started doing with rings is:

• I snug things down finger tight get the gap “even”, as close as possible by eye.
• Then I grab a “loose” feeler gauge (I keep a small box of them around) that fits perfect on all sides with them just finger tight.
• I mark it with blue tape. That is now my starting gap for those rings on that scope.
• I verify reticle level plumb, one more time.
• Then start my criss-cross, tighten a little each time until I have reached 18 inch lbs on my fix it sticks.
• I always take a photo of the scope position fore and aft for reference and I put paint marks on the rail under the rings to index.

…..

 

[Rob01]

Long story, some how serial number not visible. Possible reason to charge that amount. My razor gen3 happen turret issue, new scope elevation turned very hard and tight. I send it back and 2 weeks later received other new scope. Is it Vortex warranty, no question!

@Scott_at_Vortex have you heard of this?

 

[MechanicGino]

What I started doing with rings is:

• I snug things down finger tight get the gap “even”, as close as possible by eye.
• Then I grab a “loose” feeler gauge (I keep a small box of them around) that fits perfect on all sides with them just finger tight.
• I mark it with blue tape. That is now my starting gap for those rings on that scope.
• I verify reticle level plumb, one more time.
• Then start my criss-cross, tighten a little each time until I have reached 18 inch lbs on my fix it sticks.
• I always take a photo of the scope position fore and aft for reference and I put paint marks on the rail under the rings to index.

…..

It’s a great idea and way to do. Question; you look like way professional installer. What do you think one piece scope mount lapping? I use to NF, MPA and mostly SPUHR, almost never alignment tools are pointing each other perfectly! That mean tolerating some tiny offset? Thanks for helping the community!

 

[Holliday]

It’s a great idea and way to do. Question; you look like way professional installer. What do you think one piece scope mount lapping? I use to NF, MPA and mostly SPUHR, almost never alignment tools are pointing each other perfectly! That mean tolerating some tiny offset? Thanks for helping the community!

No, I’m just a guy who has learned from a lot smarter people around here. I am good at coming up with little systems to simplify things though.

I don’t lap rings. I buy quality rails and quality rings. Never had a problem. On Remington actions, I do epoxy bed the rail to the receiver.