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Posted: 2/14/2007 8:25:43 AM EDT
[#1]
Simply install the G.I. barrel nut wrench on the torque wrench at a right angle (90-degrees). When the barrel nut wrench is installed in this manner the effective length of the torque wrench is not changed and no correction is required.
If you install the barrel nut wrench so it points in the same direction as the torque wrench it acts as an extension, which increases the torque wrench's effective length, and correction is required. Correct as follows: Measure length of torque wrench from center of grip area to center of drive (square drive stud where you attach the barrel nut wrench). This is the effective length of the torque wrench (L). Measure length of barrel nut wrench from center of drive (1/2-inch square drive hole where it attaches to torque wrench) to center of wrenching flats. In this case, the "center of the wrenching flats" is the line between the two wrenching pins directly across from each other. This is the effective length of the extension (E). Multiply the required torque by effective length of the torque wrench (L). Divide this result by (L + E). Result is reading required on torque wrench to apply necessary torque. For example: Required torque = 100 inch-pounds Effective length of torque wrench = 12 inches Effective length of extension = 2 inches Therefore (L + E) = 14 inches 100 X 12 = 1200 1200 / 14 = 86 Shawn Dodson FirearmsTactical.com |
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Posted: 2/14/2007 9:36:12 AM EDT
[#2]
That's good information. Your target range is 31-45 ft lbs. and do not exceed 80 ft. lbs. Put a little antiseize (permatex) on the threads and lightly tighten and loosen the barrel nut three times to work out any play before giving the final torque value, and hopefully you will get an index with your gas tube within the target range.
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Posted: 2/14/2007 3:18:27 PM EDT
[#3]
Good information indeed. I will try that out this evening. Thanks a million for the help.
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Posted: 2/14/2007 5:12:01 PM EDT
[#4]
Actually, that's useless information. All of the torque specifications already account for the additional length of the barrel wrench. |
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Posted: 2/14/2007 7:26:50 PM EDT
[#5]
Now I am confused! So now that I set my barrel and used the 90 degree rule with a click at 55 foot pounds what might the true value be?
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Posted: 2/14/2007 7:33:27 PM EDT
[#6]
Who gives a shit? A torque range of 35 to 80 ft lbs is a hard target to miss. If you had to put a little effort on it and you've got it aligned correctly to install the gas tube then you should be good to go. After doing a few dozen you won't even need the torque wrench any more unless you just want to be extra certain. |
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Posted: 2/14/2007 8:22:24 PM EDT
[#7]
nuff said. fucken twist away.
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Posted: 2/14/2007 8:56:52 PM EDT
[#8]
exactly. |
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Posted: 2/14/2007 11:22:56 PM EDT
[#9]
What a truly ignorant statement. If what you say is true, all barrel wrenches will have identical measurements between the 1/2" drive and center of the wrench diameter. All three of my wrenches have different distances, thus producing different torque values that are "built into it". Set torque the way the rest of the world does it, at 90 degrees! |
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Posted: 2/14/2007 11:28:21 PM EDT
[#10]
Don't let these yahoo's confuse you. Shawn had it right. |
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Posted: 2/15/2007 5:12:18 AM EDT
[#11]
Thanks gashole. I did a little bit of research. (talked to an oldtimer neighbor) The 90* idea is dead on.
No quicker way to end an aggressive arguement than to just agree. I used that method last night and it worked great. Thanks guys. |
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Posted: 2/15/2007 8:23:47 AM EDT
[#12]
What Hoplophile is saying could be true for whatever standardized length torque wrench is used in a military armory but for us civilians the torque wrenches and barrel wrenches are most likely a different length then the standardized ones the military uses. But in reading my copy of the TM it doesn't specify what angle at which to put the barrel wrench on the torque wrench. I think the people that wrote the TM just figure that if you are reading this you should know how to make the torque wrench work for you. |
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Posted: 2/15/2007 8:57:13 AM EDT
[#13]
55 ft/lbs. You're good to go. 90-degrees is standard shop practice when torquing screw fasteners with a crowfoot. When I torque the barrel nut I use a Sturtevant Richmont CCM 1200I snap action torque wrench. Cheers! Shawn Dodson FirearmsTactical.com |
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Posted: 2/15/2007 9:26:46 AM EDT
[#14]
What is comes down to is who do you want working on your nice gun or giving you advice on your nice gun. Someone who doesn't give a shit? Not everyone has the befefit of doing this for a living and it is a disservice for those just learning. So take a little interest. |
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Posted: 2/15/2007 1:28:12 PM EDT
[#15]
With any barrel nut system that requires alignment of the barrel nut in order for the gas tube to slide through it, it WILL NOT MATTER which way you install the torque wrench on the barrel nut wrench.
This is because there is such a wide RANGE of torque that's acceptable AND YOU MUST ALIGN THE BARREL NUT. Now, if you torque it to 30ft-lbs and then have to twist it another 10 degrees to get it to align, what's the difference if you torqued it to 60ft-lbs and had to still go 3 more degrees to align? The net torque is the same (whatever was required to align the barrel nut) If you want to argue specifically about the proper use of a torque wrench to meet an EXACT TORQUE VALUE (which is certainly not required for barrel nuts), then Shawn's method with the wrench 90 degrees is certainly correct. It's just DOES NOT MATTER IN THE CASE OF BARREL NUTS. |
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Posted: 2/15/2007 2:27:29 PM EDT
[#16]
Randall,
What if you would have been lined up at 30 Ft-Lbs with the barrel wrench at a 90 to the torque wrench but instead you put the barrel wrench on stright with the torque wrench and since you had the wrench set at 30 Ft-Lbs the torque on the nut would be, let's say around 35 Ft-Lbs, then you would be just over being lined up. I don't see a need to go any farther then you have to if you don't have to. Do you? |
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Posted: 2/15/2007 2:47:03 PM EDT
[#17]
You would have known it was going to align just before 30 ft-lbs because you already torqued it 3 times to seat the threads together. On your 4th time, just bring it to alignment. If you were 2ft-lbs under 30, it's fine... |
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Posted: 2/15/2007 2:54:03 PM EDT
[#18]
That sounds fine I guess.
Thanks Randall. |
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Posted: 2/15/2007 4:50:24 PM EDT
[#19]
This a very concise question, to which Shawn gave a textbook answer to. The textbook does not have a chapter heading on "Gashole's Method" or "Randy's Method". No one was arguing there is a range of acceptable torque value's or that there are acceptable methods to get to that a barrel nut tight. There TM lists torque values, no good engineer in the world would allow a technical writer to assume torque values are built into the wrench. It was a good question that got a good answer untill "Here's how I do it" got interjected. |
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Posted: 2/15/2007 5:09:44 PM EDT
[#20]
I set my torque wrench to 960 in/lbs (80 ft/lbs) and torque the barrel nut after its been hand tightened. Believe it or not, I've had situations in which 80 ft/lbs has been reached before the barrel nut aligns with the receiver's gas tube port, and the same barrel nut does not reach 31 ft/lbs when its aligned with the previous slot. The solution? Use a different barrel nut.
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Posted: 2/15/2007 5:30:46 PM EDT
[#21]
Which is perfect because you are actually checking for OVERTORQUE (which I have found to be more probable) rather than UNDERTORQUE. I have shims that fix this problem without changing the barrel nut. You can also SOMETIMES torque and re-torque the nut a dozen more times and get some extra travel due to thread burnishing. If that fails, lap the front of the receiver. |
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Posted: 2/15/2007 5:45:09 PM EDT
[#22]
I knew that the wide torque range was more of a safety margin so one would not overtorque the barrel nut. But what I did not know was how to achive the objective without pulling the threads on my upper.
One more thing to keep in mind is that on rare occasiond overtorquing a barrel could cause the barrel indexing pin to deform slighty. It would only take a bit of deformation then one could run into the problem of not being able to sight their rifle (windage). Ohh yeah, my momma taught me to never argue with an idiot. The onlookers might have trouble telling the Two apart. Thanks again for the "great info" |
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Posted: 2/15/2007 5:47:08 PM EDT
[#23]
There's not that much difference in the locations and the original post states that he's using a GI wrench. |
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Posted: 2/15/2007 6:18:59 PM EDT
[#24]
Except that it was quoted from the wrong text book.
Army TM 9-1005-319-23&P p 3-41 (in the instructions for installing the barrel assembly) "9. Using combination wrench (10) and torque wrench, torque barrel nut assembly (9) to 30 ft-lbs (40.4 N-m). Torque is measured when both wrenches are used together." p 3-44 (in the instructions for installing the flash hider) "15. Torque compensator (12) to 15-20 ft-lb (20-27 N-m) using combination wrench (10) and torque wrench. Torque is measured when both wrenches are used together." p3-81 (in the instructions for installing the butt stock) "6. Using combination wrench (5) and torque wrench, torque lower receiver extension to 35-39 ft-lb (47 25 52 65 N-m). Torque is read when both wrenches are used to gether." RTFM before you give any more advice, asshole. |
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Posted: 2/15/2007 6:24:21 PM EDT
[#25]
When installing normal barrel nuts, you'll find that the teeth will begin to deform and break if you get much past 80 ft-lbs. The nuts used on free-float tubes don't have this protection, however. |
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Posted: 2/15/2007 6:31:46 PM EDT
[#26]
Absolutley, at 90 degrees. Appearantly no one will change your mind, at least you give a shit now. |
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Posted: 2/15/2007 6:38:51 PM EDT
[#27]
You're still talking out your ass. 
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Posted: 2/15/2007 6:44:50 PM EDT
[#28]
You got me there. That is not good practice. |
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Posted: 2/15/2007 7:28:45 PM EDT
[#29]
My torque wrench has an effective length of 16 inches. The GI barrel nut wrench ("combination wrench") adds 2 inches to effective length. If I adjust the torque wrench to apply 80 ft/lbs and use the GI barrel nut wrench as shown in the illustration, and I reach 80 ft/lbs as indicated by the torque wrench I'd have overtorqued the barrel nut by 10 ft/lbs.
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Posted: 2/15/2007 8:05:05 PM EDT
[#30]
As I already posted once in this thread, "If you had to put a little effort on it and you've got it aligned correctly to install the gas tube then you should be good to go." |
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Posted: 2/15/2007 8:12:47 PM EDT
[#31]
Guys, If I may interject. Although there was One very good answer to my question there was also some very helpful information that I can use down the road.
I hope all this backlash is in good fun. Oh, btw. I think he is talkin out his "gashole" silly. |
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Posted: 2/15/2007 8:12:57 PM EDT
[#32]
So, it turns out that if you are using your barrel nut wrench at 90 degrees to the torque wrench that you would be under-torquing the barrel nut if you went to 30ft-lbs to check for alignment at minimum torque. Therefore, to follow the manuals properly, keep the torque wrench in-line with the barrel nut wrench because the specs are built around this configuration of torque wrench and barrel nut wrench. While it may not be the right way, it's the military way!  Case closed. |
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Posted: 2/15/2007 9:36:29 PM EDT
[#33]
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Posted: 2/15/2007 9:49:35 PM EDT
[#34]
I've had teeth start to bend well before 80 Ft-Lbs. What are the problems with free-float tube barrel nuts? If anything I thought they would be stronger, except for the aluminum ones. |
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Posted: 2/15/2007 9:53:52 PM EDT
[#35]
The length of the Military barrel nut wrench is a fixed standard because they are all the same. Since that's what the torque specs are built around, it does not matter. The picture showing the torque wrench on the barrel nut wrench is as good of a statement as words. It makes the most sense when you have both tools in your hand and no prior knowlege of using a torque wrench. Then there's this that was posted above...
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Posted: 2/15/2007 10:30:12 PM EDT
[#36]
It's not necessarily a problem. The teeth of the normal barrel nut will fail long before the threads on the receiver get damaged, which serves as a protection for the more expensive receiver in teh event that you get somebody really cranking on the wrench. The receiver doesn't get that protection when your dealing with the barrel nuts used on most free-float tubes so it is more important that the builder be aware of the max torque being applied. Then again, if you're using a free-float tube then you are probably hoping to build something more accurate and that means you'll want to be careful about the amount of torque being applied anyway... |
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Posted: 2/15/2007 10:32:20 PM EDT
[#37]
You've got to remember that the instructions in the TM are written for soldiers, not mechanical engineers.
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Posted: 2/16/2007 7:39:53 AM EDT
[#38]
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Posted: 2/16/2007 7:46:58 AM EDT
[#39]
+
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Posted: 2/16/2007 7:53:11 AM EDT
[#40]
 Oh... You ment the teeth on the FF nuts are stronger. Thanks. |
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Posted: 2/16/2007 8:31:14 AM EDT
[#41]
I disagree. If you have a torque wrench that's 12" long and one that's 24" long and both are capable of producing 50ft-lbs of torque (measured at torque wrench output), and each of these wrenches are assumed to be calibrated within acceptable specs, then each of these torque wrenches SHOULD produce the exact same amount of torque to the barrel nut wrench. |
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Posted: 2/16/2007 10:20:35 AM EDT
[#42]
True, If you set them for 50 Ft-Lbs both the 12" and 24" length torque wrenches will put 50 Ft-Lbs on the drive hole in the barrel wrench but even when useing the same length extension, once you multiply the set torque by the extended length of the torque wrench with the barrel wrench attached to it divided by the length of the torque wrench with no extension on it the actual torque applied will be different. 50 multiplied by 14 divided by 12 = 58 50 multiplied by 26 divided by 24 = 54 |
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Posted: 2/16/2007 11:48:48 AM EDT
[#43]
I still disagree with this whole theory. If you have 50ft-lbs coming into the wrench, the length of the wrench can not make a difference. Are you saying that if I used an impact wrench and had an inline slipper clutch set to exactly 50ft-lbs that somehow the 50ft-lbs from the longer wrench is somehow stronger? I understand and agree that the offset of the barrel nut wrench will increase the torque, but the length of the wrench is completely irrelevant when the torque applied to the input side of the barrel nut wrench is identical. Taking this theory in another direction, if you had a 12" and 24" torque wrench and each were set exactly the same torque and you had them coupled to push against each other. In your theory, the longer wrench would somehow be stronger. Of course this can't be true if each wrench is pushing exactly the same torque. So, since we have determined that 50 ft-lbs is 50 ft-lbs no matter the wrench length, how can it play into the total torque applied at the end of an offset? I say that the formula is invalid and based around beam type torque wrenches where the actual beam length and force matter. |
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Posted: 2/16/2007 12:48:39 PM EDT
[#44]
Well, this has been an educational post. My only question is: if I don't have a torque wrench, and I use the multi-tool to tighten up the barrel nut to the point where I'm able to properly align the gas tube, will I be o'kay? (that's tightening past the point of hand tight then going further to align the gas tube)., Based on what Randal posted, I'm inclined to think that I'm good to go. This also did not involve muscling the multi-tool, nor limp wristing it. I did this to install my YHM free float rail. Oh I do plan to purchase a torque wrench to test my install before I go firing several hundred MORE rounds.
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Posted: 2/16/2007 2:04:03 PM EDT
[#45]
I'm fresh out of ideas. I don't know any more then the math. I wish Eugene Stoner was here. |
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Posted: 2/16/2007 2:27:19 PM EDT
[#46]
This is simple mechanics. Torque is torque. Measured in ft-lbs. Simple mechanics says the math is WRONG. If you were using a simple lever that's different lengths, THEN you would apply different forces to the different lengths to end up at the SAME torque. As we are talking about different length torque wrenches doing the SAME torque, it's JUST NOT POSSIBLE for there to be a difference based on the length. Of course, on a 12" long wrench, you would be applying 50 lbs of force to the lever and on a 24" long wrench, you only need to push 25lbs, but the net effect is 50 ft-lbs either way. So indeed, the longer wrench is easier to use and in-fact my 1/2" torque wrench that I use for barrel nuts is about 20" long and MUCH easier to use than a 12" long 3/8" drive torque wrench. If there is something else missing here and I am missing some big piece of the picture, please 'splain it to me real simple because I'm slow...
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Posted: 2/16/2007 3:28:44 PM EDT
[#47]
Thanks randall. I wish I knew enough to know if you were wrong so I could correct you but I don't.  So "Einstenis", should the math that is used to make up for the added extensions be thrown out now that it looks to be inaccurate? |
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Posted: 2/16/2007 6:10:23 PM EDT
[#48]
Another meaningless thread about this torque concept and barrel nuts.
 Snug three times. Then index until the next gas tube slot lines up. Why do people try and make this complicated? |
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Posted: 2/16/2007 6:18:39 PM EDT
[#49]
Because we don't want to waste our expensive Snap-on torque wrenches.  
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Posted: 2/16/2007 6:21:34 PM EDT
[#50]
I will be installing a Noveske railed tube on a AR10 on Sunday - which doesnt have gas tube slots on the barrel nut. It even comes with two different barrel nuts to let you pick which ones lines up with the correct torque. I will have to blow the dust off my Craftsman (oh the horror) torque wrench it looks like.
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