How Much Torque?

[Drenalin]

I just picked up a Ruger American in .223, an SWFA 6x with the SWFA rings, and a Monstrum rail. I can't find a torque spec with any of this shit. I've got a Wheeler Fat Wrench.

For rail to action, the most clear information I could find came from EGW where they say to use 20 in-lbs. That seems like a joke; am I wrong, or does anybody have a recommendation on dry torque for this connection? My current plan is to tighten them slowly until I can't turn them any further.

For rings to rail, I'm seeing recommendations from 40-65 in-lbs. I'm assuming 45 dry would do the trick?

For the ring caps, I'm planning to go with 18 in-lbs (dry).

Somebody throw me a bone here and tell me I'm good to go, or if I'm about to screw this up.

 

[Dos XX]

I got these from the respective manufacturers. SWFA should be able to provide the same.

Scope Rings:
NF:		NF used the words do not exceed for their torque specs
Crossbolt	68	in lbs
Cap Screw	25	in lbs
Farrell:		No do not exceed, just a range
Crossbolt	50-55	in lbs
Cap Screw	15-20	in lbs
Scope Base:
Farrell	20-25	in lbs
March Rings:		March also says do not exceed
Crossbolt	60	in lbs
Cap Screw	20	in lbs
Cap Screw	15	in lbs

 

[TheHammer]

The fasteners dictate the torque per manufacture, obviously not all screws are created equal. The warne rail I just mounted for a customer with 8-40 screws, I set them at 20in-lbs then went back over at 22in-lbs, ring bases I’ve seen recommended at 30in-lbs and up typically I use purple thread locker.

 

[Formidilosus]

Bases that are mounted with 20 to 30in-lbs for the screws, will 100% move with side impacts and general rough handing eventually (unless glued/bonded down the full length such as Tikka factory pic rails).

 

[Drenalin]

Bases that are mounted with 20 to 30in-lbs for the screws, will 100% move with side impacts and general rough handing eventually (unless glued/bonded down the full length such as Tikka factory pic rails).

So go snug, then flip the wrench and give it a 1/2 turn?

 

[Formidilosus]

So go snug, then flip the wrench and give it a 1/2 turn?

I’m not going to say what you should do. I do not accept something moving. Degrease everything with alcohol or brake cleaner, loctite, paint pen, or nail polish the screws, then I go tight, tight- probably 65 in-lbs or more; or where the little Allen wrench starts to deform.

 

[ResearchinStuff]

form, you're talking 65 in-lb on the cross-bolts, not the dink 6-48 or 8-40 screws that hold the rail down, right?

pretty sure the dinks can't handle anywhere near 65 in-lb.

 

[Formidilosus]

form, you're talking 65 in-lb on the cross-bolts, not the dink 6-48 or 8-40 screws that hold the rail down, right?

pretty sure the dinks can't handle anywhere near 65 in-lb.

Nope. The base to receiver screws- sink screws (though you are making a case for not using a system that requires peeny little screws). I don’t use a torque wrench on them- I go tight using the allen/torque wrench that is generally provided, and go until I feel it is about to strip.

 

[redneckbmxer24]

LOL don’t torque your base screws to 65 in lbs unless you want to be extracting those little screws. 6-48 screws which are what that uses will handle 20 in lbs, so that’s what I would use for the base. Degreased and then blue or orange loctite.

For the ring cross bolts, those SWFA rings use very cheap steel, chances are you’ll strip them if you go to 65. You can do that with other rings but not those. 45-50inlbs should be fine.

For the ring caps 15-18in lbs. I would degrease and loctite those too.

 

[Formidilosus]

LOL don’t torque your base screws to 65 in lbs unless you want to be extracting those little screws. 6-48 screws which are what that uses will handle 20 in lbs

So what happens from your experience when 20in-lbs is used for base screws and a side impact happens?

 

[ResearchinStuff]

i've started using JB weld between bases and receivers to help those screws in the situations where a better mounting option can't be used. I had one rifle strip the 6-48 receiver threads at ~10 in-lbs,

Anyhow, I double checked, even with a bump for more thread engagement at the finer pitch the specs *edit: do not* indicate those little screws can take 65, and definitely not more than once. If more clamping force is needed to survive a side impact, then all the more reason why 6-48 and really even 8-40 have no place in scope mounting systems.

Torque Table Standard Bolt Sizes SAE

The following suggested tightening torques provide an excellent starting point for determining torque requirements. Remember, you may need to vary these numbers somewhat based on the individual joint or the amount of fastener lubrication.

www.engineersedge.com

 

[Formidilosus]

i've started using JB weld between bases and receivers to help those screws in the situations where a better mounting option can't be used. I had one rifle strip the 6-48 receiver threads at ~10 in-lbs,

Anyhow, I double checked, even with a bump for more thread engagement at the finer pitch the specs indicate those little screws can take 65, and definitely not more than once. If more clamping force is needed to survive a side impact, then all the more reason why 6-48 and really even 8-40 have no place in scope mounting systems.

Torque Table Standard Bolt Sizes SAE

The following suggested tightening torques provide an excellent starting point for determining torque requirements. Remember, you may need to vary these numbers somewhat based on the individual joint or the amount of fastener lubrication.

www.engineersedge.com

From a functional standpoint, base screws are an absolute joke. No one would start with “this thing needs to not move no matter what” and would use those little screws.


Despite people that haven’t tried it or done it, the base screws probably the weakest link in the whole system besides scope themselves. 20in-lbs in them will move quite easily and regularly, not just from drops but from general rough field use.

 

[Deere83]

Form, what do you suggest gluing the rail to the base with?

 

[Deere83]

Rail to receiver… sorry

 

[redneckbmxer24]

So what happens from your experience when 20in-lbs is used for base screws and a side impact happens?

Worse case scenario they will sheer off. That’s completely irrelevant though to you suggesting exceeding what 6-48 screws can handle by three times. They aren’t head bolts.

If he torques them how you suggest he won’t even get the opportunity to find out because they’ll be snapped off in his action.

You should call up Ruger and EGW and tell them they don’t know what they’re doing.

 

[Formidilosus]

Worse case scenario they will sheer off. That’s completely irrelevant though to you suggesting exceeding what 6-48 screws can handle by three times. They aren’t head bolts.If he torques them how you suggest he won’t even get the opportunity to find out because they’ll be snapped off in his action.

Show me where I told him to tighten to 65in-lbs? And no, shearing off from an impact is not what happens first- what happens is the base moves and there is a zero shift. It’s reproducible and provable.

You should call up Ruger and EGW and tell them they don’t know what they’re doing.

Don’t need to call anyone- Is this another subject that you are speaking definitively on, yet have no experience experimenting with the subject?

 

[redneckbmxer24]

Show me where I told him to tighten to 65in-lbs? And no, shearing off from an impact is not what happens first- what happens is the base moves and there is a zero shift. It’s reproducible and provable.






Don’t need to call anyone- Is this another subject that you are speaking definitively on, yet have no experience experimenting with the subject?

If you’re deflecting the wrench and stripping the screws you’re exceeding 65.

What are you suggesting he torque them to then since the 20-30in lbs window you says isn’t enough already exceeds what 6-48 screws can handle on the top end?

Nobody is expecting a rifle to never shift zero when abused, that’s a completely unreasonable expectation. You live in some fantasy land that rifles should never have a zero shift under any circumstances. You can only do so much to idiot proof a rifle.

I too am interested in your bonding procedure and what you use.

 

[Formidilosus]

If you’re deflecting the wrench and stripping the screws you’re exceeding 65.

What are you suggesting he torque them to then since the 20-30in lbs window you says isn’t enough already exceeds what 6-48 screws can handle on the top end?

What? You absolutely can tighten good 6-48 base screws to 20 in-lbs. There can’t be an across the board suggested torque because every company has different strength/quality screws. Hence why I said I use the included wrench until I feel it is about to strip or give.

Nobody is expecting a rifle to never shift zero when abused, that’s a completely unreasonable expectation. You live in some fantasy land that rifles should never have a zero shift under any circumstances. You can only do so much to idiot proof a rifle.

And you know this because you have tried? There’s a couple dozen people from this board alone that have seen what I do to my rifles, and what they can do to them without losing zero.

Legitimate question- how is that you are so confident in beliefs that you haven’t tried, tested, or validated?

 

[Formidilosus]

Form, what do you suggest gluing the rail to the base with?

I don’t suggest anything, as I haven’t done rigorous experiments to see which is the better/best way. The last few I had done were by gunsmiths and I believe they used JB weld, Steel Bed, and Loctite 380. No release agent on the rail or action, but- release agent in the screws holes only. I also had a couple welded on.

The best answer is to choose a rifle that has an integral rail to begin with.

 

[Bubblehide]

Show me where I told him to tighten to 65in-lbs?

Form, he is taking 2 things you said about 2 different types of screws, blending the 2 together and applying it to the weakest of the 2 types. But, I think you already knew that.