School me on Scope ring torque

[peaches]

Anybody ever confirm their chi-com torque wrench is even close to in spec?

With experience you can feel when you got it right. Tighten with your finger tips and stop when you get to the 'squeek' point. You can tell when you are about to exceed torque. Same goes from small screws to lug nuts.

 

[XLR]

This is a good one because ARC rings recommend 55 inch lbs for their scope screws (yes you read that right). So what makes rings like these different from others?

https://www.americanrifle.com/web/content/30470

 

[ResearchinStuff]

when we tighten a fastener, strain is applied to the bolt so that the fastener elastically elongates. This elongation of the fastener provides the clamping force that keeps things tight. too much strain and you're going to strip threads, or plastically deform the bolt, ruining it permanently.

Since elongation and strain are difficult to measure with normal equipment, appropriate torque values are calculated for standard fasteners. Depending on the pitch and diameter of the threads different amounts of torque are required to cause the same elongation and provide the same clamping pressure. The threads also are subject to friction while turning, so a good portion of the applied torque gets consumed by overcoming that friction rather than causing elongation of hte fastener. Combine these factors, and that's why you see much higher torque values for larger bolts than smaller ones.

ARC sort of explains this at the bottom of the sheet you linked. Wikipedia does a more thorough job: https://en.wikipedia.org/wiki/Bolted_joint#:~:text=Typically, a bolt is tensioned,being fastened by the bolt.

edit to add: the comment about the accuracy of the readily available torque wrenches is poignant, and not easy to confirm at home.

 

[hicountry1]

25inch lbs, locktight on bases, 20 inch lbs on the rings On all my talleys.

On vertical splits, 30inch lbs bottom, 20inch lbs top of split

25inch lbs bases in locktight

Never an issue, scope tube damage or scope slip.

Run that on everything from 218bee thru 300Rum

 

[General RE LEE]

~28 lbs Leupold Mark 4 rings