PDA

View Full Version : NSS Supply Torque Spec



RC20
06-24-2016, 08:40 PM
Being a mechanic I was interested in getting down to the details on the NSS recommendation for the Nut they sell.

I know most just use some version of hand tight or hit it with a hammer, that is not my approach though hard to tell what I would do if I did not have the torque wrench already.

I also have an Armorers video and they say 90 ft lbs.

Adding to the confusion is no matter what, you have some kind of offset on the nut wrench and that would change things (though I was also reminded that if you go at 90 degrees then the offset is negated)

That said I contact Jim to get exactly what was meant in the Action Wrench Instructions .

A bit of surprise in that they use the closest half inch cutout to the nut. More natural for me I guess to use the further one (and for sure with the breaker bar taking it off)

NSS recommendation is 45 to 50 ft lbs. Using the close hole, that is a 2 inch offset that is not much difference even if you do not calculate the offset.

I have a follow up to Jim on that point though its getting far to nuanced for any real world affect as torque is easily 15% off if set perfectly,

Also note that NSS recommends anti seize. All lubes (or bare threads ) have their own affect on actual torque but any lube has a dramatic affect over dry threads.

Not sure how to get a sticky but I did some sleuthing and saw the question come up frequency but had no one had hard data from anyone as to exactly what was meant and what offset was used (or not) to achieve that.

And thank NSS for providing baseline information and data how it was achieved. There is at least some technical base for setting it as well as response when the question comes up.

Texas10
06-24-2016, 10:56 PM
James recommended 50 ft. lbs for my Criterion barrel, and plain oil or copper anti-seize on the threads. After posing the question on this forum about what anti-seize to use and having read that copper based anti-seize should not be used on Stainless, I used plain ol' aluminum based AS.

I bought the small (stubby) barrel nut wrench and set it at 90 degrees to the torque wrench like you did to negate the need for calculating the arm, and torqued the precision ground barrel nut to 45 ft. lbs, which felt to me to be plenty tight, based upon my years as a mechanic.

Bottom line, the new barrel shoots very well.

Edit to correct torque to FT. lbs.

short round
06-25-2016, 01:43 AM
Hey Texas, should be ft lb for barrel nut.

Texas10
06-25-2016, 07:57 AM
Thanks for catching the typo, SR. Yes, it is indeed FOOT lbs,

LongRange
06-25-2016, 08:53 AM
interesting....ive never torqued more than 30ft lbs i also dont use anti seize or any lube for that matter but ive never had a barrel on more than about 8-10 months.

RC20
06-25-2016, 12:43 PM
I bought the small (stubby) barrel nut wrench and set it at 90 degrees to the torque wrench like you did to negate the need for calculating the arm, and torqued the precision ground barrel nut to 45 ft. lbs, which felt to me to be plenty tight, based upon my years as a mechanic.


I actually did go with the far 1/2 inch hole straight out and did the offset calculation (wrong the first time). My serious wrench turning days are too many years behind me though I still do compressor work occasionally that has toque spec involved.

What I don't think I ever ran into (or lost in time) was that 90 deg does negate a need for offset calc. Any time in the past I needed to use an extension there was not room for anything other than straight out (Quincy compressor in particular uses a bolt from under the head so I get to do it from time to time, but your only space is straight out and not a lot of that.). I never did engine full time, it was always a lot of electrical work, systems install with engines just part of the mix from time to time.

This application being free and clear the 90 degree works but that was new to me. Fun to learn or re-learn things.

What I liked about NSS is a flat stated spec. Going into this new that's a mental help, if you don't work with that its not a concern, if you do you know the ramifications for not doing it right can be pretty bad. I did recommend to Jim they state which hole to use and 90 degrees removes any change though its only a couple ft lbs at 2 inches the closer hole is so even straight out not much change.

Having gone through the video again with their 90 ft lb recommendation it was huh? So I reviewed it, email Jim to get the skinny as to what their instructions meant.

I also read the reviews on Savage and the 70 ft lbs they use (or reported to)

That's where the lube comes in. For a 1 inch fastener, lube can change the situation almost 100% (vastly over torqued vs dry) .

Within that even the type of lube has a factor. Any head bolt I worked on not only had the torque spec but the type of lube, from engine oil to the old peanut butter (and often now anti seize though not nearly as prominent when I was doing the more serious wrench turning). We always followed that, no ad libing.

I suspect this application has a pretty wide tolerance. From what I saw taking the first one apart, the threads in the receiver had stuff on them (lock tite?), but the nut threads did not. Ergo that may explain the higher torque for Savage factory.

Still its good to have a solid basis of starting, something does not work right you can figure out too little, too much and establish a good starting point as well as solid information to go by, whacking it with a hammer sends shivers up my spine, not arguing it works, it just is against all I ever learned in this regard.

FW Conch
06-25-2016, 03:00 PM
Because I had several torque wrenches when I started with Savages, I also use them. I have always used Nickle Antiseize, used the short hole at 90dgrs, and torqued to 40ft/lbs. Since 2007, and untold barrel changes, it has worked just fine.

Yes, some kind of Thread Locker is often used on factory Savages. The last 3 that I broke down, when they did not come loose with 100ft/lbs of torque, I went straight to the propane torch. Black gunk bubbled up from the nut and it came right loose. When the nut cooled on the barrel threads, it was "glued" back on again. Had to reheat to get it off the barrel, then clean up the mess.

Since I have always had torque wrenches, I do not "wack with a hammer" either. But, like Bill Pa, I am set up to change barrels without removing the scope, and I don't want to subject a scope to that shock.

Just the way I do it...Jim :-)

Steelhead
06-25-2016, 03:38 PM
I use 35 ft lbs
always worked for me!

RC20
06-25-2016, 04:08 PM
Because I had several torque wrenches when I started with Savages, I also use them. I have always used Nickle Antiseize, used the short hole at 90dgrs, and torqued to 40ft/lbs. Since 2007, and untold barrel changes, it has worked just fine.

Yes, some kind of Thread Locker is often used on factory Savages. The last 3 that I broke down, when they did not come loose with 100ft/lbs of torque, I went straight to the propane torch. Black gunk bubbled up from the nut and it came right loose. When the nut cooled on the barrel threads, it was "glued" back on again. Had to reheat to get it off the barrel, then clean up the mess.

Since I have always had torque wrenches, I do not "wack with a hammer" either. But, like Bill Pa, I am set up to change barrels without removing the scope, and I don't want to subject a scope to that shock.

Just the way I do it...Jim :-)

With the 2 inches that add a couple foot pounds so close to the NSS Nut recommendation. As noted by others less seems to work fine though I stick with recommended. Too many years of following the specs in that regard.

It will be interesting to see how the newer Savage barrel comes off. I had the wifes hair dryer on standby for the first one just in case. It may well need more heat if still too sticky and I have the torch for backup. Probably ok and I overthink this, but I always go with the least amount of force (or heat) needed (keeping in mind sometimes its better to go with max force to start with but most cases not)