View Full Version : What Torque Wrench Are You Using?
I've put together a couple of lowers before, but now I want to put an upper together. What torque wrench are you allbusing to put the barrel and flash hider on with?
Calibrated R/H Elbow, Mk I
Evil Black Rifle
09-18-21, 09:09
Any reasonable quality torque wrench will be accurate enough, and do the job right. If you buy a click type torque wrench remember to re-set it to ZERO when you put it away.
And remember to orient the barrel nut wrench/socket 90 degrees to the torque wrench.
Hammer_Man
09-18-21, 09:34
Craftsman and Husky build good torque wrenches for the average consumer.
I bought a Husky 1/2” one at Home Depot a few years ago. It was made in the United States.
Any reasonable quality torque wrench will be accurate enough, and do the job right. If you buy a click type torque wrench remember to re-set it to ZERO when you put it away.
Reset it to its lowest setting. Not all click type torque wrenches go as low as 0.
And remember to orient the barrel nut wrench/socket 90 degrees to the torque wrench.
Not if you're using a barrel nut wrench with the correct length. The given torque includes the arm of the barrel nut and the barrel nut is to be straight.
Not if you're using a barrel nut wrench with the correct length. The given torque includes the arm of the barrel nut and the barrel nut is to be straight.
I don't get it. Could you draw a picture?
I use a Sears bending beam torque wrench.
Black_Sheep
09-19-21, 17:34
A Snap-On 1/2” drive torque wrench leftover from my 30+ years of wrenching.
I don't get it. Could you draw a picture?
This is taken from the manual. You will note the barrel nut wrench is inline with the toque wrench, not at 90 degrees (Item 15). The torque figures given in the manual include the added length of the barrel nut wrench
https://photos.smugmug.com/photos/i-nmbbmWh/0/5c9c51f6/X4/i-nmbbmWh-X4.png
titsonritz
09-19-21, 19:12
CDI 1/2" drive.
Pressingonward
09-19-21, 19:22
This is taken from the manual. You will note the barrel nut wrench is inline with the toque wrench, not at 90 degrees (Item 15). The torque figures given in the manual include the added length of the barrel nut wrench
https://photos.smugmug.com/photos/i-nmbbmWh/0/5c9c51f6/X4/i-nmbbmWh-X4.png
Interesting...so what is the center-to-center length between the barrel nut and the torque wrench square drive on the "proper" barrel nut wrench? Need to know that to calculate the actual torque value. Partially explains why I've seen several different torque specs floating around.
Interesting...so what is the center-to-center length between the barrel nut and the torque wrench square drive on the "proper" barrel nut wrench? Need to know that to calculate the actual torque value. Partially explains why I've seen several different torque specs floating around.
If you have barrel nut wrench with the right length (I don't think anyone makes one the wrong length) you set the wrench inline with the torque wrench, set the torque to 30 ft/lbs and go. No calculations needed.
Interesting...so what is the center-to-center length between the barrel nut and the torque wrench square drive on the "proper" barrel nut wrench?
I am fairly sure it is 2.0"
Joe Mamma
Thank you. Iraqgunz gave 30 to 80 as the range. So the actual torque range is higher than that? It looks like I need to know the length of the official torque wrench as well as the extension length to make the conversion?
https://www.terex.com/docs/librariesprovider7/tech-tips/techtip_53.pdf
Hafa Adai! The torque range is from 30-80 ft./lbs. If you feel you need the wrench, set it at 30 ft./lbs and then torque until you hit it. Then mark where the barrel nut is at with a white paint pen. Then I would loosen the nut, remove the torque wrench and then slowly tighten again (I would work the threads several times) first.
Keep tightening until you hit the next spot where the nut will allow you to insert the gas tube. Then put it all together.
And remember to orient the barrel nut wrench/socket 90 degrees to the torque wrench.
JFC. Not this BS again...
If I recall the difference is 5% according to a mechanical engineer. In short with the torque range, he said the difference is a moot point. Coupled with the accuracy of the tool, exactly where it's held and the lubricity of the parts.
Plus, this helps for task such as using the Magpul wrench with a torque wrench on the lock ring(castle nut)
https://www.engineersedge.com/manufacturing_spec/torque_wrench_1.htm
http://i.imgur.com/XFtm2Sz.jpg (https://imgur.com/XFtm2Sz)
Hammer_Man
09-20-21, 06:50
I always orient my torque wrench 90 degrees to the barrel nut tool. I haven’t had a barrel come loose yet.
Failure2Stop
09-20-21, 13:04
I always orient my torque wrench 90 degrees to the barrel nut tool. I haven’t had a barrel come loose yet.
Most companies that understand assembly and torque will spec the torque for the wrench being at 90 degrees to the installation tool.
So recommended torque wrenches are the ones with the dial, not the click ones, right? As you can see, I'm very mechanically inclined.
I have a cobalt so-so torque wrench. But after building a few guns, you don't need the torque wrench unless you were beaten for coloring outside the lines.
Like Iraqgunz used to say... my torque wrench is my arm. (now if I'm working on a more fragile job (non 7000 series upper, and/or non steel barrel nut, i'll get the torque wrench out so I don't gall threads. For real guns, I don't bother.
So recommended torque wrenches are the ones with the dial, not the click ones, right? As you can see, I'm very mechanically inclined.
Either type will do, but I use the click type.
I always orient my torque wrench 90 degrees to the barrel nut tool. I haven’t had a barrel come loose yet.
It's such a wide torque range, it isn't really critical except at the very bottom.
Most companies that understand assembly and torque will spec the torque for the wrench being at 90 degrees to the installation tool.
Normal industry wide SOP is set the torque extender to 90 degrees to avoid the math, or calculate the correction. It's what I've advocated in the past for installing the barrel nut.
However, I've since learned the manual specifies the proper torque is with the correct barrel nut wrench set inline with the torque wrench and the added length is already figured into the torque range. If you have references to the contrary, please share. I don't want to be passing along incorrect data.
It's such a wide torque range, it isn't really critical except at the very bottom.
Normal industry wide SOP is set the torque extender to 90 degrees to avoid the math, or calculate the correction. It's what I've advocated in the past for installing the barrel nut.
However, I've since learned the manual specifies the proper torque is with the correct barrel nut wrench set inline with the torque wrench and the added length is already figured into the torque range. If you have references to the contrary, please share. I don't want to be passing along incorrect data.
I think you are passing along incorrect data but for the application we are talking about it probably makes zero difference. Sorta like throwing the deck chairs off of the Titanic slow the ships sink rate.
I think you are passing along incorrect data but for the application we are talking about it probably makes zero difference. Sorta like throwing the deck chairs off of the Titanic slow the ships sink rate.
As usual, YOU are incorrect.
Sent from my iPhone using Tapatalk
As usual, YOU are incorrect.
Sent from my iPhone using Tapatalk
Correct me.
I have a cobalt so-so torque wrench. But after building a few guns, you don't need the torque wrench unless you were beaten for coloring outside the lines.
Like Iraqgunz used to say... my torque wrench is my arm. (now if I'm working on a more fragile job (non 7000 series upper, and/or non steel barrel nut, i'll get the torque wrench out so I don't gall threads. For real guns, I don't bother.
So, you'd think a normal person could do it by feel. I'm working on the first lower I ever built. I did that one by "feel." Now my buffer tube will roll back and forth between two places where I staked the castle nut. It only had about 10k rounds on that lower. A gunsmith I am not. I've built a few since then, and it makes me wonder when they'll let go now.
TacticalMark
09-21-21, 22:11
I use mostly a 3/8dr snap on split beam torque wrench or the digital snap on 3/8dr
I’ve liked my 1/2” CDI click torque wrench for auto and firearm work. I also have a Wheeler Fat Wrench for quick not so critical work. I’m really wanting to get a set of Fix It Sticks. Other than that I’d look at Snap-On or Proto or other U.S. made click style wrenches. I don’t like twin beam type for numerous reasons. And I’m not sold on the electric type.
Correct me.
GH41, MistWolf provided the correct information in one of his posts above. The only issue, and I don't think this was mentioned yet in this thread, is that the threads should be lubricated. That also changes the torque rating significantly--not the amount or torque applied, but the amount of tightening of the barrel nut.
I say this is an issue because the use of a thread lubricant is part of the correct way (as per the US Military manual that MistWolf is citing). I believe it is part of the instructions on the page before the page that MistWolf cited, and it says "Apply molybdenum disulfide grease (WP 0045, item 18) to the threads before installation."
There are many different ways to do this, and many of them will work. But if someone is looking for the "correct" way, that is what MistWolf cited.
Joe Mamma
Here's a comparison review of a Snap On and an ICON torque wrench
https://youtu.be/ck_O5U1Tyz8
I'm genuinely interested in hearing what Jack has to say. He's very knowledgeable and a good source of the latest info and I am here to learn.
gunnerblue
09-22-21, 08:43
So, you'd think a normal person could do it by feel. I'm working on the first lower I ever built. I did that one by "feel." Now my buffer tube will roll back and forth between two places where I staked the castle nut. It only had about 10k rounds on that lower. A gunsmith I am not. I've built a few since then, and it makes me wonder when they'll let go now.
I use a Snap-on, though I don't think a wrench is absolutely necessary. Like others have said, the torque range is very broad.
Which barrel nut and muzzle device are you using?
So, you'd think a normal person could do it by feel. I'm working on the first lower I ever built. I did that one by "feel." Now my buffer tube will roll back and forth between two places where I staked the castle nut. It only had about 10k rounds on that lower. A gunsmith I am not. I've built a few since then, and it makes me wonder when they'll let go now.
I'd re-install that. Stakes will break loose when wrenched off. Re-install with more torque, and re stake.
I'd re-install that. Stakes will break loose when wrenched off. Re-install with more torque, and re stake.
I just completed that a couple of evenings ago. Of course, that was still without a torque wrench because I haven't ordered one yet. I'll have one for future builds. When I first started I didn't figure I'd ever build enough to need the proper tools. Hindsight and all that. I've slowly been getting them.
It's such a wide torque range, it isn't really critical except at the very bottom.
Normal industry wide SOP is set the torque extender to 90 degrees to avoid the math, or calculate the correction. It's what I've advocated in the past for installing the barrel nut.
However, I've since learned the manual specifies the proper torque is with the correct barrel nut wrench set inline with the torque wrench and the added length is already figured into the torque range. If you have references to the contrary, please share. I don't want to be passing along incorrect data.
The .mil manual specifies a particular tool, yes the math is included.
HOWEVER, this can’t be used as a general statement. Proper use of an adapter is 90* to the torque wrench or do the math.
37 years in aviation
TA x L L + A = TW
The .mil manual specifies a particular tool, yes the math is included.
HOWEVER, this can’t be used as a general statement. Proper use of an adapter is 90* to the torque wrench or do the math.
37 years in aviation
TA x L L + A = TW
It looks like we've both been in aviation for about the same length of time!
So, you know that AC 43.13-1B Para 7-40 and Fig 7.2 covers torque and how to calculate the correct setting when using torque adaptors. However, I could find nothing in Chapter 7 authorizing the use of a torque adaptor set to 90 degrees. If you know where it is, I'd be obliged if you passed along the information.
The beginning of AC 43.13-1B under PURPOSE also says-
The repair data may also be used as approved data, and the AC chapter, page, and paragraph listed in block 8 of FAA form 337 when:
a. the user has determined that it is appropriate to the product being repaired;
b. it is directly applicable to the repair being made; and
c. it is not contrary to manufacturer’s data.
The important part is c. "not contrary to manufacture's data". In the matter of torquing the barrel nut using the barrel nut wrench, the AR manual says to use the barrel nut wrench inline with the torque wrench and set to 30 ft/lbs to start. Do not compensate for the added arm of the barrel nut wrench. This is assuming the use of the correct barrel nut wrench.
(I do realize that setting the torque adaptor to 90 degrees is an acceptable practice IAW with c. as noted above.)
Hammer_Man
09-27-21, 13:08
Does anybody know the measurements of the tool listed in the TM? I’d like to know the distance of the 1/2 drive cut out to the part the interfaces with the barrel nut.
I am more familiar with the military manuals, NAVAIR 01-1-8, and TM 1-1500-204-23-9, both of which, in addition to showing the calculation noted above, gives the formula for the extension at some angle, so that if you find yourself using a 90 degree offset, TW = TA . . . .
66518
A = 2 inches
With a standard 18" torque wrench the difference is 10%.
"The important part is c. "not contrary to manufacture's data". In the matter of torquing the barrel nut using the barrel nut wrench, the AR manual says to use the barrel nut wrench inline with the torque wrench and set to 30 ft/lbs to start. Do not compensate for the added arm of the barrel nut wrench. This is assuming the use of the correct barrel nut wrench"
If this is true the manual doesn't say torque to "X" ft/lbs. It says set the wrench to "X" ft/lbs and use the "Y" wrench oriented to inline. It doesn't specify what the barrel nut is actually tightened to but it isn't 30 ft/lbs.
"The important part is c. "not contrary to manufacture's data". In the matter of torquing the barrel nut using the barrel nut wrench, the AR manual says to use the barrel nut wrench inline with the torque wrench and set to 30 ft/lbs to start. Do not compensate for the added arm of the barrel nut wrench. This is assuming the use of the correct barrel nut wrench"
If this is true the manual doesn't say torque to "X" ft/lbs. It says set the wrench to "X" ft/lbs and use the "Y" wrench oriented to inline. It doesn't specify what the barrel nut is actually tightened to but it isn't 30 ft/lbs.
That's correct.
"The important part is c. "not contrary to manufacture's data". In the matter of torquing the barrel nut using the barrel nut wrench, the AR manual says to use the barrel nut wrench inline with the torque wrench and set to 30 ft/lbs to start. Do not compensate for the added arm of the barrel nut wrench. This is assuming the use of the correct barrel nut wrench"
If this is true the manual doesn't say torque to "X" ft/lbs. It says set the wrench to "X" ft/lbs and use the "Y" wrench oriented to inline. It doesn't specify what the barrel nut is actually tightened to but it isn't 30 ft/lbs.
But then, just to be contrary about the situation Drawing numbers 8448522 - Upper Receiver and Barrel Assembly (M16A1), 9349050 - Upper Receiver and Barrel Assembly (M16A2), 12972680 - Upper Receiver and Barrel Assembly, and 12997148 - Upper Receiver and Barrel Assembly (Heavy Variant), all have the same note on barrel installation (see below). This note does not specify a tool and states simply that the nut is to be torqued to 30 to 80 ft-lbs.
https://i.imgur.com/o3YQuYc.png
So, the manufacturer's drawings and the manuals (this goes back all the way to the TM 9-1005-249-23 & P) have disagreed on the actual torque for the barrel nut (and flash suppressor, and receiver extension btw) for at least the last 45 years. The fact they have never bothered to consolidate the two tells me: It ain't that big a deal.
Also, you will note the "correct" lubricant for the threads is Dow Corning Molykote G, which actually is an anti-seize compound, not a GP grease, like MIL-G-21164 (aka Aeroshell 33MS), so the " . . . or equivalent . . . " covers a lot of ground.
Track #2, of Weird Al Yankovic's "Bad Hair Day" Album.
But then, just to be contrary about the situation Drawing numbers 8448522 - Upper Receiver and Barrel Assembly (M16A1), 9349050 - Upper Receiver and Barrel Assembly (M16A2), 12972680 - Upper Receiver and Barrel Assembly, and 12997148 - Upper Receiver and Barrel Assembly (Heavy Variant), all have the same note on barrel installation (see below). This note does not specify a tool and states simply that the nut is to be torqued to 30 to 80 ft-lbs.
https://i.imgur.com/o3YQuYc.png
So, the manufacturer's drawings and the manuals (this goes back all the way to the TM 9-1005-249-23 & P) have disagreed on the actual torque for the barrel nut (and flash suppressor, and receiver extension btw) for at least the last 45 years. The fact they have never bothered to consolidate the two tells me: It ain't that big a deal.
Also, you will note the "correct" lubricant for the threads is Dow Corning Molykote G, which actually is an anti-seize compound, not a GP grease, like MIL-G-21164 (aka Aeroshell 33MS), so the " . . . or equivalent . . . " covers a lot of ground.
Track #2, of Weird Al Yankovic's "Bad Hair Day" Album.
LOL! If there wasn't conflicting data, the guy on floor would wonder if he got the right blueprint.
However, that's not the complete print. Assembly prints normally include notes for how certain processing are performed including torque.
https://pistol-forum.com/attachment.php?attachmentid=77697&d=1632832166
However, that's not the complete print. Assembly prints normally include notes for how certain processing are performed including torque.
Yes, that is not the complete drawing, there are the other two pages of that drawing, the parts list, the assembly equipment list, the inspection equipment list, and the quality assurance provisions, but what you see above is how the torque specified.
Now, here's the problem:
As you and hk_shootr have gone to establish the torque correction equation given an extension, you will have noted that the correction calculation involves both the extension length [A] and the torque wrench length [LL].
The torque wrench specified in the manual (TM 9-1005-319-23 & P) comes in two flavors, one the torque wrench in "Shop Set, Small Arms: Field Maintenance, Basic, Less Power", P/N SC4933-95-A11 (NSN 4933-00-754-0664), and Torque Wrench, ft-lbs, P/N A-A-411 (NSN 5120-00-640-6365). Neither of these torque wrenches part numbers are a specific brand or model torque wrench but are a description of a commonly found commercial item, and mainly deals with the accuracy and repeatability requirements. The one thing that is specifically not stated is the overall dimensions of the wrench, so the length of the wrench is anywhere from 17-1/2" to 24".
The different lengths of the acceptable types of torque wrench in the manual gives a +/-5% variation on applied torque.
This is why when you make assembly drawings you put the actual torque down not the indicated torque for the collection of tooling assemblies. Because that one specified piece of tooling with break and somebody will have to figure out to do the job with non-specified tools, or somebody will change the design of the specified tool without telling you and for a year everything will be built wrong, until you find out.
Failure2Stop
09-29-21, 16:43
30ft/lbs minimum with the tool in line with the torque wrench is still below where most would want a barrel nut, so being 90 degrees off or inline really doesn't mean anything, ESPECIALLY because that barrel nut needs to be advanced to get the gas tube through the teeth gaps on a TDP M4/M16, and 80ft/lbs even with the wrench inline is safely below the "actual" limit of a good receiver and barrel nut.
Also remember that the US Army mislabeled both the gas key screw torque and the "castle nut" torque at one point, so that manual should be considered "reference" more than anything else.
30ft/lbs minimum with the tool in line with the torque wrench is still below where most would want a barrel nut
What actual torque do you recommend for a nut that doesn't require indexing?
The torque wrench specified in the manual (TM 9-1005-319-23 & P) comes in two flavors, one the torque wrench in "Shop Set, Small Arms: Field Maintenance, Basic, Less Power", P/N SC4933-95-A11 (NSN 4933-00-754-0664), and Torque Wrench, ft-lbs, P/N A-A-411 (NSN 5120-00-640-6365). Neither of these torque wrenches part numbers are a specific brand or model torque wrench but are a description of a commonly found commercial item, and mainly deals with the accuracy and repeatability requirements. The one thing that is specifically not stated is the overall dimensions of the wrench, so the length of the wrench is anywhere from 17-1/2" to 24".
The different lengths of the acceptable types of torque wrench in the manual gives a +/-5% variation on applied torque.
What you say is true. I've never found anywhere specifying TQ wrench length for TQing the barrel nut. Truth is, after getting a few assembled uppers under my belt, I don't use a TQ wrench anymore. I don't advocate others doing the same because I don't know their level of skill or experience. I also assemble one upper at a time and give the barrel nut my full attention. If I were working a line, I would definitely use a TQ wrench in case my attention wanders.
This is why when you make assembly drawings you put the actual torque down not the indicated torque for the collection of tooling assemblies. Because that one specified piece of tooling with break and somebody will have to figure out to do the job with non-specified tools, or somebody will change the design of the specified tool without telling you and for a year everything will be built wrong, until you find out.
For the most part, true. But I have run into prints with very specific TQ specs, such as using the TQ extender inline with the wrench, or TQ to so many degrees after snugging the fastener and so on.
30ft/lbs minimum with the tool in line with the torque wrench is still below where most would want a barrel nut, so being 90 degrees off or inline really doesn't mean anything, ESPECIALLY because that barrel nut needs to be advanced to get the gas tube through the teeth gaps on a TDP M4/M16, and 80ft/lbs even with the wrench inline is safely below the "actual" limit of a good receiver and barrel nut.
Also remember that the US Army mislabeled both the gas key screw torque and the "castle nut" torque at one point, so that manual should be considered "reference" more than anything else.
In aviation, I'm not allowed to consider an approved manual or any approve data a reference. It has the force of federal regulation.
But I do get your point. I also agree with you and Lysander that we're given wide latitude and the important thing is to apply enough TQ to the barrel nut that it doesn't come loose.
I asked for your input because I want to learn and avoid working in the vacuum of isolation.
Thanks to you, Lysander and GH41 for the discussion.
. . . . or TQ to so many degrees after snugging the fastener and so on.
That is a "torque-to-yield" (TTY) fastener, and that is another kettle of fish altogether.
TTY gives a very uniform clamping load under a very wide variation of lubrication conditions.
C4IGrant once mentioned 40 ft pounds as the sweet spot for barrel torque. Might give him a shout for clarification. Was in a thread where he built a blaster using a Bravo stainless barrel shooting really tight groups. I think he showed us something like a 1/2 inch group.
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