Torque wrench for AR 15 barrel?

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Brianma65

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Hey there,
Wondering what torque wrench to get.
CT has a Dewalt 50-150 ft lbs 3/8 drive. $100
And a mastercraft 50-250 ft lbs 1/2 drive. $70
The MC is a big sucker though:)
I’m gonna be using a torque tool/ reaction from True north.
I think I may need the 1/2 drive?

Also, what’s the general torque value,for the barrel?

I’ve watched a couple of vids, both saying 70 ft lbs.
With backing it off a bit and re torquing ,a couple of times.

Thanks
 
Don't forget you have to allow for the length of the tool when you set the torque value, if you set it to 70 that value is directly on the centerline of where the socket goes, it increases as you add leverage with the tool.

https://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm


As far as the wrench get the 1/2" drive, it will be more useful on other things and the length is nice for nice easy torque application.
 
70 ft/lbs is waay over.

Average I've been taught is 30-50, 50 being a firm MAX.
Judging by that, none of the options listed would work with a 50 ft/lbs max.
 
MrSharp said:
Don't forget you have to allow for the length of the tool when you set the torque value, if you set it to 70 that value is directly on the centerline of where the socket goes, it increases as you add leverage with the tool.

https://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm
Thanks



As far as the wrench get the 1/2" drive, it will be more useful on other things and the length is nice for nice easy torque application.
Click to expand...
I’ve read that the tool should be on a 90 degree angle,from the wrench.
This would give you correct torque value.
Yes?
 
MrSharp said:
Don't forget you have to allow for the length of the tool when you set the torque value, if you set it to 70 that value is directly on the centerline of where the socket goes, it increases as you add leverage with the tool.

https://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm


As far as the wrench get the 1/2" drive, it will be more useful on other things and the length is nice for nice easy torque application.
Click to expand...

Or put the torque wrench at a 90 degree angle so the length of the wrench is the same as if it was in the middle of the barrel nut negating any leverage advantages, also it’s hard to find a lower torque torque wrench with a 1/2” drive, much easier to get a 3/8 and a 3/8 to 1/2 drive adaptor.
 
I have the CT MC you speak of, since it can be used in other applications (tires and such). It fits my AR wrench but I believe it can handle a 3/8” drive as well. The torque spec is 30-80 ft/lbs, I usually go around 60. And have the torque wrench at 90 degrees to the AR wrench, so the torque is at the full value the wrench displays.
 
Use a torque wrench 90° to the barrel nut tool. MidwayUSA's videos on this show it done the WRONG way.

Marine armorer's manual specifies 30-80 foot pounds. Apply a LITTLE silver or copper antiseize - NOT oil or grease - to a couple of spots on the lower receiver threads and torque to 30 pounds. The barrel nut will spread the antiseize into the threads. Use a breaker bar - NOT the torque wrench - to back it off. Repeat once or twice, then torque to 30 foot pounds. Go up a few foot pounds each time until the barrel nut is aligned to allow you to pass the gas tube. The gas tube should NOT touch the barrel nut.
 
I had just contacted Aero Precision about this for their upper and barrel nut and the say to set the torque wrench at 55 foot pounds and use their supplied barrel wrench inline with the torque wrench.
 
Brianma65 said:
there’s nothing smaller than 50 Ft lbs at CT.
Click to expand...

There should be. I got a Mastercraft Maximum 1/2" one and does anything from 10 to like 150 ft lbs.

Brianma65 said:
HA Ha, this is my first AR build, I’m a bit concerned it might blow to smitherines.... :)
Click to expand...

AR barrel nut doesn't need much. HECK my first AR I built in 2005, I didn't use one, put it in between my legs and tighten. Never heard the barrel nut ever coming off, TV press pass owned it after it went to another person.
 
TrxR said:
I had just contacted Aero Precision about this for their upper and barrel nut and the say to set the torque wrench at 55 foot pounds and use their supplied barrel wrench inlinewith the torque wrench.
Click to expand...

That will generate more then 55 ft/lbs on the barrel nut, but Aero must know that and did the math based on using their tool and BAR nut. I assumed you’re using their BAR nut as that’s why you’d call Aero.

Brianma65 said:
I’ll try it at 60 and call it a day:)

Thanks
Click to expand...

Just remember to line up the tube notch as FyreFighter suggested.
 
You can't set a single value and call it a day because you may have to tighten or loosen to get the gas tube lined up.
 
FyreFighter said:
You can't set a single value and call it a day because you may have to tighten or loosen to get the gas tube lined up.
Click to expand...

Right, you just go for 30 ft/lbs and work up slowly until you line up, unless your barrel nut is proprietary and doesn’t need alignment. Right around 60 is where I normally end up. My experience only.
 
I own a fairly high dollar Snap on 1/2” digital torque wrench and have never used in on my ARs.
I snug hand tight with some anti-seize on the threads and then torque half way to the next hole to line up with the gas tube and back off. Do this twice more then torque to next hole that lines up. The torque value could vary from 15 to 50 ft/lbs so that is why many knowledgeable builders and gunsmiths are reticent to nail down a specific number.
The only thing that would make me modify that procedure would be if using a float tube that allowed for variation in how the gas tube aligned with the torque on the barrel nut. Even still, I can’t see requiring more than 35-40 ft/lbs.
 
Brianma65 said:
Hey there,
Wondering what torque wrench to get.
CT has a Dewalt 50-150 ft lbs 3/8 drive. $100
And a mastercraft 50-250 ft lbs 1/2 drive. $70
The MC is a big sucker though:)
I’m gonna be using a torque tool/ reaction from True north.
I think I may need the 1/2 drive?

Also, what’s the general torque value,for the barrel?

I’ve watched a couple of vids, both saying 70 ft lbs.
With backing it off a bit and re torquing ,a couple of times.

Thanks
Click to expand...

Don't buy the Mastercraft one, the torque doesn't go low enough at 50 min. I have a Dewalt 3/8" one I bought from Canadian Tire and it starts at 20 and use a 3/8" to 1/2" adapter. If you get into the 50lbs torque on some of the aluminum barrel nuts they will start to deform. After learning this the hard way I now go to 30 and then back off and increase 3 times to end around 36lbs torque. Never had any issues.

Here is the one I have and it's better than the Mastercraft one I had. http://www.canadiantire.ca/en/pdp/dewalt-3-8-in-drive-torque-wrench-0589677p.html#srp

OkayShooter said:
There should be. I got a Mastercraft Maximum 1/2" one and does anything from 10 to like 150 ft lbs.
Click to expand...

Are you sure about that? It might be marked from 10lbs but likely doesn't kick in until you reach 50lbs even if you have it set lower.
 
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