Set the torque wrench 90 degrees to the extension and torque the barrel nut to the recommended ft lbs. The calculations for the most have already been worked out by the manufacturer. Thanks for the video. I build too seldom to keep all those in mind. So far that is.
The correct torqure for the barrel nut is 30 ft-lb + whatever it takes to achieve alignment. Once you reach 30 ft-lb it does not matter what the torque is. Alignment must be achieved and it must be more than 30 ft-lb. You don't want to know. On the third tighten-back off (this smooths the threads and gets a good even fit on all threads) once you reach 30 ft-lb, put the torque wrench away and replace it with a breaker bar, and advance to alignment. That's it Two more suggestions, use a good solidly mounted vise. Second suggestion, do NOT use barrel vise jaws for barrel installation, use an action block. Your action block came with an insert that slips into the upper receiver where the bolt carrier would go. You must use it to prevent collapse of the receiver walls.
Depending how heavy & long the barrel is I shoot for higher torque, also barrel extension to upper fit also comes into play. Use reaction rod also, a must need if you ask me.
Eh i disagree. The reason why the US infantry is a model for the world is because generally, most of our soldiers AIM their zeroed rifles, not hip fire AK47s like African child soldiers. That being said, accuracy is absolutely important. That being said, barrel harmonics comes into play. A rifleman should know the actual torque used on their barrel nut for a particular load. If theyre using 55 grain ammo from a particular ammo maker, theres a particular torque setting that will produce the tightest groups. Using 75 grain Hornady TAP bthp, i can achieve 1/2 MOA at 300 yards with a torque spec of 48 ft lbs with my 18 inch barrel.
@@harold1733 I'm confused by your comment. How is one to know up front when installing the barrel how it will shoot with a given torque and a given bullet weight and shape from a particular manufacturer, given that the barrel must first be installed before the gun is fired? And how do you know your particular gun won't shoot as well at 35 ft lbs or 47 ft lbs or 49 ft lbs or 55 ft lbs, etc? I mean, did you start with 30 ft lbs, shoot some groups, then move to 31 ft lbs, shoot some groups, and so on up to 48 ft lbs? And when you reached 1/2 MOA at 48 ft lbs. did you try 49 ft lbs to see if you got 1/3 MOA? Your 48 ft lbs value is oddly specific; would plus or minus 48 ft lbs yield meaningful differences in accuracy? If so, how do you know it's the torque and not yourself or weather conditions or differences in ammo from one round to the next? "A rifleman should know the actual torque used on their barrel nut for a particular load." Are you suggesting that gunsmiths install barrels using a torque value with a particular load in mind? Even if a barrel could be torqued to a spec somehow related to bullet weight, then presumably the barrel would be inaccurate for any other bullet weight (given your assertions), which doesn't make that barrel particular ideal. Who want's a rifle that can accurately shoot only one specific brand of cartridge? What happens when you can't find that specific brand of cartridge? Also, your contentions completely ignored barrel quality. A shitty barrel torqued to your value for a given cartridge from a particular maker will still yield shitty results. Also, how does your method account for undersized uppers like those manufactured by BCM, where the barrels are installed using heat?
@@blueeyeddevil1 i build my rifles from parts. I go with my barrel's twist to determine bullet weight range. I settled with 75 because I bought a shitload of em after seeing my friend shoot them out of his rifle and the brand and ammo was gtg, and there was a sale and will spec the rifle out to shoot them. I go and start low end (35-80 ft* lbs) so 35 lbs, go shoot groups. Then Ill jump 5 lbs up, shoot groups. In my case, I went all the way up to 50 lb, the groups got worse, went down to 46 got better than 45, until I landed on 48 foot pounds. Could my magic number have been 50 lb? Probably. Maybe I didnt sleep much that day or I shot my groups on too much coffee or the wind affected my groups or whatever external variable. All my experimentation and prodding, I got satisfactory groups at 48 foot pounds. I tried the best I could to be systematic and consistent. And I dont buy shit parts. I go with JP or Criterion or Proof Research or a custom MosTec or Excalibur. The intent for the rifle is important. Long range? Short range? Hunting? Varmint? 416R? 4150CMV? Duty? Competition? Length? Twist? Contour? Gas length? If you dont like my methods, do your research and come up with your own.
@@harold1733 Thanks for the response. If you think that amount of effort pays off, good on you. I didn't say anything about liking or disliking your methods, just wondering how you arrived at your conclusion given all the variables. I agree that torque can play a role in accuracy, especially at extremes of high (overnight) and low (loose). That said, I built several rifles that consistently shoot 1/2 MOA on a sled with hand loads and I never had to take things to that level, especially with higher end barrels. But okay, to each his own. Happy shooting.
You definitely are not a real engineer. As a REAL engineer myself, I know, and YOU should know too, that no engineer ever did any real engineering to determine an ideal torque value. It's all just armchair enthusiasts jerking eachother off over made up shit. As long as you have the thing on tightly, it doesn't matter how much torque you apply.
At Deutsch Aerospace we "engineers" use to "sling ink on vellum" and actually included a page of mathematical data and conclusions. The day any of you actually were required to take a class in slide rule and do the "math" is the true test of real "engineering." The next year we were required to buy that TI SR-50 which was about $200 back then...I actually still have the thing. Using applied force to cut, bend, shape and form various metals along with the blueprints for fixtures and molds, this shit is child's play. Today we just plug in "netfabb" or "solidworks" and be done with it. Still doesn't look as awesome as a shaded in inked vellum drawing framed and hung on a wall.
I'm so glad you made this video because I've tried for years to explain how anything you use on a torque wrench that adds to the overall length gives an inaccurate reading at the head of the wrench (antique needle or dial & clicker)
Math has never been strong point, but the way you explained it really help me to understand it. Now I want to go back and re torque the barrels on my rifle. Thanks for the lesson!
Very well stated and thank you for your time and effort. Having done warranty work for Colt, it was always a fairly large range that was acceptable and, most importantly, it could never be exact because you then have to rotate the nut to the next possible position to clear the gas tube. Besides that, whether the threads are "wet" or "dry," anti-seize (which I do use)or not, and have you compressed the threads a few times before you finalize the torque all come into play.
Do not use "anti-seize" that has metal particles, such as Neverseize or the copper stuff. Those bits of zinc or copper grab the aluminum and make it difficult to tighten smoothly. The barrel nut wants to move in jerks. Use a smooth grease, preferably with moly disulfide. This is ordinary brown wheel bearing grease for disk brakes. If you don't have that, regular grease gun type grease is fine.
Thank you! When getting in to this hobby it was immediately apparent that torque would vary based on type of wrench used etc. Leverage was the term I thought about based on point of force. The math is tough for me to follow but I really appreciate your explanation, I'm one of those worry worts that needs to know proper specs so I can sleep at night.
So to keep it simple and ensure I understand correctly.. If I want to be as exact as possible.. I either keep the barrel nut wrench perpendicular to the torque wrench? And then it should apply relatively exact force to the setting on the torque wrench? And if for some reason I prefer to keep the barrel nut wrench in line with the torque wrench then do the math that accounts for the extra length added?
Since the specs are typically a wide range, "don't make this an over complicated issue" is the final sentence said at the end of the video after a huge discussion and analysis. The answer could just be said in about 3 min= have the barrel wrench tool at 90 degrees oriented to the torque wrench so the length added by the tool does not affect the radial distance from force applied.
All joking aside for those that don't understand torque and how you achieve it this is a very good video well explained and everybody should know the math. Remember what your math teacher said one day , math is going to save your life
NOW I remember why I dropped out of college algebra! (could not keep up with the professors). Some are meant to just shoot the dang thing.... Going elsewhere to look for 'the answer'.
People get so worked up between the the 180 or 90 degree offset. In reality, it doesn't matter. Unless you are adding several inches of length. For this specific application, the applied torque to the barrel nut does not require precision. Even if you do everything right, in terms of setting your torque wrench to a specific ft-lbs, you are applying torque a surface that is not smooth, meaning energy loss due to friction and heat. I am glad to see a video of an engineer that understands mechanics explains this topic.
As an engineer from way back when we used slide rules and slung ink on vellum, even the mfg recommends that.... Most auto mechanics going by the Motors Manuals do the same...kinda an understood thing.
@@keithlucas6260 I retired as a Nuclear Mechanical Systems Inspector. Before that I spent many hours working on my own vehicles. Stickler for doing thing correctly. You might be surprised how many people don't have the same understanding you have.
@@calvinroyals6463 ....Thanks....went into the Air Force and was offered Colorado Springs AFA in '76 after I already had my degree....long story short was given a security clearance that's classified. After an injury I was "retired" and got the job with Deutsch during this "leave of absence." Funny how things don't always go as planned.....ended up "slinging ink" for Bianchi Gunleather in Temecula and happen to be "that guy" who developed the locking welt holsters you see Safariland selling (John's old business bought his business). I'm actually just retired from Baker Hughes as their top master toolmaker....found it more satisfying "turning handles." There isn't anything from manuals to CNCs, I can't setup, program or run and get $30 to $40 an hour plus overtime. My "baby" I'm playing with now happens to be a 1948 CASE VAC utility tractor... plus I have my own shop to "piddle" with everything in.
@@keithlucas6260 You are an example of what my cousin says. The cream rises to the top. I was a slow learner took me 20 years as Nuc 10 of them in Refueling before I put in for Work Leader to advance my career. Would like to have learned how to set up CNC. Everything I did was so far removed from my military MOS. Artillery men don't have much to do in civilian life. Funny I have made some holsters for friends and myself. All hand sewn too cheap to buy a machine. Well take care and be well.
The one time I had a torque-wrench to tighten my barrel nut, the nut flared before I got to the 45lb setting. I looked at it thinking 'no way', and slid the handguard to it, where it stopped, unable to go all the way home. I did everything in the mfr directions, so I'm back to the fail-safe 'gut wrenching' method which has never caused me any issues in the dozens of times I used it on my own AR builds. I was able to grind the flare flat enough to allow the handguard to seat and it has been all good since, but I'm still shaking my head when I see that AR. I will say this, though...definitely clean the threads and use the specified grease or anti-seize, half tighten and loosen your barrel nut a couple times before your final 'torquing' or your torque is not what you think it is. I've been shown that by my armory friend when we were in the Marines and then he showed me a stripped upper where the threads looked like waves rather than threads. He said it comes from the aluminum characteristics wanting to grab and lock-up against the steel barrel nut when torque is beginning to be applied which causes friction/heat then the thread locking action premature to actual final torque. The '33' grease takes that out of the equation as it should.
yea I have tried to explain to people that "the longer the dingus end the less the torque" for ages and some people don't get it. if'n you don't believe it use a long extension with an impact gun to remove a lug nut... now try it with a short socket.
LOL The whole [L(w) + L(e) x Cos(A)] / L(w) section is basically a correction that says mathematically: for the purposes of determining torque, the measurement from the center of rotation to where the force is being measured is the only part that counts. Which is very true. The Cosine of 90 degrees is 0 (i.e. 0% or none) and the Cosine of 0 is 1 (i.e. 100% or all). So L(e) x Cos(A) basically states that we're using some percentage of L(e) based on the angle and adding that to L(w) to get the true length of rotation, then dividing it by the length of the wrench to get the total applied adjustment for the wrench. Sometimes math is funny with regard to how true it is.
Everyone says to torque it accordingly but tight is tight and even if you torque it you still have to go past the specs on some nutts to allow gas tube to pass through correctly i tighten my with out a torque wrench. When i torque to specs ive had them come loose and yes i seizen the threads. So fuck the specs. I know what works and i served 8 years in the marines also and know my shit.
You get it so this video wasn't for you, brother. It's for all those that don't understand the concept and incorrectly state the facts. Thank you for your service. Speaking of Marines, I just spent way too much time in the field with a staff sergeant but a good dude nonetheless.
You have a window of 35 to 80 foot pounds. Torque to 35 loosen 35 loosen 35 loosen then set it to 40 and go until you can line it up or if it doesnt need lined up then its good. Its not a aerospace bolt on a space shuttle or tires on your car. Dont "Nuke" it like we said in the navy.
Aerospace/Space hardware has very tightly controlled torque specs. They don't "nuke" it either. Over torquing aerospace bolts is worse than slightly under torquing them.
The wrench is already 90 degrees. The diagram you shown is when the wrench is straight but the wrench on the barrel nut is already 90 degrees so you’re applying incorrect torque of 180 degrees. Keeping the wrench straight and the hook is at 90 degrees is correct.
steel nut connecting the steel barrel to the alum. alloy upper receiver.........30 to 80 pounds. there is a reason for the spec. to be varied so much.That would be that it doesnt have to be so tight to stay in the correct position. hence the locking tab on the barrel locking into the slot in the receiver....Its All Good......Just use a cresent wrench and turn it till its tight, problem solved.Dont worry about head space as it will only be 3-4 thousands at the most...that is the way its designed ...to be worked on in the battlefield with one or two tools....HAVE A GOOD DAY.
T=FL F force in pounds L length of the arm in feet One could avoid trig by using a T-Square and measuring the length of an angled wrench. Keep the square normal to (90 degrees) to the barrel and read the length from the square. No need for a calculator or trig tables
For non free-floated barrels, the barrel nut must be tight, but allow the gas tube to slide through. It must be left there, because it's impossible to tighten it enough to reach the next trough, regardless of the torque.
Salutatins from GA! great vid! it made perfect sense to this math-head wanna-be builder. Thank you for taking the time & effort to explain this rationale....ps, your outtakes were enjoyable as well!
Ever notice that even after torquing barrel nut you have to clock the nut after for gas tube clearance. Excessive torque is not needed. Once assembled the gas tube prevents it from loosening. Much like a Carter key on a castle nut.
Oh wow, You're actually supposed to use shims. So then when you are at the appropriate torque setting then you are lined up for your gas tube. You definitely don't tighten to the torque setting then loosen it to line up 👀
Awesome video. I will definitely use what you taught here. I love the detail you go into, my type of video. What torque wrench are you using? I need to buy a good quality one. Thanks
The torque specs are 30 to 80 because of the original spiked but that was used. You had to pass the gas tube between them to install it. Don't overthink it.
Outstanding commentary Professor Lonestar Patriot. I had to stop the video and go get my slide rule for the first six minutes of the video. I called my grandson and had him watch the video also. He offered me his Texas Instruments TI-30Xa Scientific Calculator LOL, LOL, LOL. I was able to follow you on the second half of the video easier. LOL (3X) again. 🐢🇺🇸🐢🇺🇸🐢🇺🇸
Could you have flipped the extension that was at 90 degrees to the wrench so that the center of the nut was inside of the center of torque wrench to get just slightly less torque than the setting on the wrench so you don't have to worry about over torque?
That's why there are plus and minus tolerances on torque specs. Close is good enough in most cases, plus no 2 torque wrenches torque the exact same. _Never_ figure that you are torquing to spec, always figure you're n the ball park. When in doubt, use another wrench to confirm.
@@F16_viper_pilot Leverage on the hand is not leverage at the socket. Two different things going on there. If I shoot a shotgun shell in an 18" barrel, and an identical shell in a 28" barrel, the amount of pressure never changes, but the velocity will. Same as with a torque wrench. The socket pressure will not change, only the felt pressure used to get it there will. Give me a lever, and I can move a mountain. But the weight of the mountain itself will never change. Changes on torquing come from the extensions, not the handles. The longer the extension, the less torque is applied through metal fatigue, stress, and twist. But even that is minimal.
OMG. at 78 years old I had to write all the figures and numbers down - now am ready to install barrel BUT can’t find my notes or my i-pad ::::: if I can find my truck keys I’ll go to a gun shop.
Thank you, I had a hard time finding this information, i finally understand the correct way to use a torque wrench, its scary how many low intelligence people are playing with guns.
With the new math 1+2 =4 so I am sure 90 degrees is really only 85%of the old 90 or is that 95% of the old 90 degrees. I think i will just stick with Gudentight.
every video I have seen; some kind of lube is used on the barrel nut/receiver thread. the addition of lube changes the torque value? reduces the torque by about half. why does no one addresses this fact.
It's the reverse to where lubricity will provide an increased applied torque; however, for this application with an anti-sieze grease, there's not a significant increase in applied torque and it does provide a more even distribution to the threads. That's why a median torque value simplifies any anomalies to where it's still within acceptable tolerances.
As a mechanic, I’ll tell you that’s not the case at all. Applying lube to a fastener does not double the applied torque, not even close. It may increase by just a little bit since the friction coefficient is reduced but nothing critical at all.
Tim Oneill , you are correct. However it would be more appropriate to say that clamping force and fastener stress go up as friction goes down with the same amount of torque. This equation relates torque to clamping force: T=KFd where: T=torque K=friction coefficient F=clamping force d=thread diameter This is a general equation for preload torque on a solid fastener. The following links explain preload torque and friction better that I can and also why torque is an awful method for retaining fasteners. I would like to add that the type of lubrication is part of the torque spec. ua-cam.com/video/lsCyAvTqcNE/v-deo.html ua-cam.com/video/XMjQTl_x3fc/v-deo.html ua-cam.com/video/fbvf4vMp4bk/v-deo.html
Good information but a little confusing, I would think your angle would’ve taken from center axis of the wrench head and the centerline of the socket on the adapter/extension regardless of the shape of the adapter. It doesn’t make sense to square off the edge of the adapter, there is a frog in Alaska that freezes during the winter and while frozen the frog stops breathing, his heart stops beating, his palms are sweaty, knees weak, arms are heavy there’s vomit on his sweater already, moms spaghetti.
Do you know how many people you just destroyed? Here is how it works, place the barrel nut ,use a little locktite, torque the barrel nut down between 35 and 80 foot pounds, back it off a few times too stretch the threads then finish the final torque and you're done
Guy Green I have an ar 15 pistol upper from ground zero precision. I’ve been looking around on how many foot pounds to torque it. Do certain company’s have different torque specs or does the 35-80 ft lbs work for all ar 15 builds? Plz help
@@brandongarcia2688 30-80 ft. lbs. is pretty standard. First of all, don't use loctite. Get yourself some aeroshell 33ms. It is less than $10. It has anti-seize and anti-gaulling properties. Coat the outside of your barrel extension with a thin layer. Coat the inside of your upper where it meets the barrel with a thin layer. Set your extension at 90 degrees to the torque tool. Set your torque tool to 30 ft. pounds. Torque it to that spec. Break it (unscrew it) using a breaker bar, not the torque wrench. Repeat that torque spec 2 more times, breaking it two more times. On the fourth go, you are going to set it to about 40 ft. pounds and tighten it. If it is properly clocked or you have a barren nut that doesn't require clocking then you are done. If you need further clocking, set your torque wrench to a higher value like 60 ft. pounds and just keep moving it ever so slightly until it is clocked correctly. Keep repeating until it is clocked but don't go over 80 ft. pounds. The only reason I incrementally increase my torque for clocking is so that I know about how much it is torqued. Happy building, friend.
One thing I have learned about torque. There is no need for it, everything I have torqued to spec has backed off or loosened up over time which is why they always tell you to torque again. If you tighten it as much as you can without straining then it is tight enough. Torquing is overrated
For all you Apple Products guys, App Store has a free app from Snap-On , Torque Source. Plug in the numbers and it give you the torque needed. While math is good, apps is better !!
Set the torque wrench 90 degrees to the extension and torque the barrel nut to the recommended ft lbs. The calculations for the most have already been worked out by the manufacturer. Thanks for the video. I build too seldom to keep all those in mind. So far that is.
The correct torqure for the barrel nut is 30 ft-lb + whatever it takes to achieve alignment. Once you reach 30 ft-lb it does not matter what the torque is. Alignment must be achieved and it must be more than 30 ft-lb. You don't want to know. On the third tighten-back off (this smooths the threads and gets a good even fit on all threads) once you reach 30 ft-lb, put the torque wrench away and replace it with a breaker bar, and advance to alignment. That's it Two more suggestions, use a good solidly mounted vise. Second suggestion, do NOT use barrel vise jaws for barrel installation, use an action block. Your action block came with an insert that slips into the upper receiver where the bolt carrier would go. You must use it to prevent collapse of the receiver walls.
Depending how heavy & long the barrel is I shoot for higher torque, also barrel extension to upper fit also comes into play. Use reaction rod also, a must need if you ask me.
Eh i disagree. The reason why the US infantry is a model for the world is because generally, most of our soldiers AIM their zeroed rifles, not hip fire AK47s like African child soldiers.
That being said, accuracy is absolutely important.
That being said, barrel harmonics comes into play. A rifleman should know the actual torque used on their barrel nut for a particular load. If theyre using 55 grain ammo from a particular ammo maker, theres a particular torque setting that will produce the tightest groups.
Using 75 grain Hornady TAP bthp, i can achieve 1/2 MOA at 300 yards with a torque spec of 48 ft lbs with my 18 inch barrel.
@@harold1733 I'm confused by your comment. How is one to know up front when installing the barrel how it will shoot with a given torque and a given bullet weight and shape from a particular manufacturer, given that the barrel must first be installed before the gun is fired? And how do you know your particular gun won't shoot as well at 35 ft lbs or 47 ft lbs or 49 ft lbs or 55 ft lbs, etc? I mean, did you start with 30 ft lbs, shoot some groups, then move to 31 ft lbs, shoot some groups, and so on up to 48 ft lbs? And when you reached 1/2 MOA at 48 ft lbs. did you try 49 ft lbs to see if you got 1/3 MOA? Your 48 ft lbs value is oddly specific; would plus or minus 48 ft lbs yield meaningful differences in accuracy? If so, how do you know it's the torque and not yourself or weather conditions or differences in ammo from one round to the next?
"A rifleman should know the actual torque used on their barrel nut for a particular load." Are you suggesting that gunsmiths install barrels using a torque value with a particular load in mind? Even if a barrel could be torqued to a spec somehow related to bullet weight, then presumably the barrel would be inaccurate for any other bullet weight (given your assertions), which doesn't make that barrel particular ideal. Who want's a rifle that can accurately shoot only one specific brand of cartridge? What happens when you can't find that specific brand of cartridge? Also, your contentions completely ignored barrel quality. A shitty barrel torqued to your value for a given cartridge from a particular maker will still yield shitty results. Also, how does your method account for undersized uppers like those manufactured by BCM, where the barrels are installed using heat?
@@blueeyeddevil1 i build my rifles from parts. I go with my barrel's twist to determine bullet weight range. I settled with 75 because I bought a shitload of em after seeing my friend shoot them out of his rifle and the brand and ammo was gtg, and there was a sale and will spec the rifle out to shoot them. I go and start low end (35-80 ft* lbs) so 35 lbs, go shoot groups. Then Ill jump 5 lbs up, shoot groups. In my case, I went all the way up to 50 lb, the groups got worse, went down to 46 got better than 45, until I landed on 48 foot pounds.
Could my magic number have been 50 lb? Probably. Maybe I didnt sleep much that day or I shot my groups on too much coffee or the wind affected my groups or whatever external variable. All my experimentation and prodding, I got satisfactory groups at 48 foot pounds.
I tried the best I could to be systematic and consistent.
And I dont buy shit parts. I go with JP or Criterion or Proof Research or a custom MosTec or Excalibur.
The intent for the rifle is important. Long range? Short range? Hunting? Varmint?
416R? 4150CMV? Duty? Competition? Length? Twist? Contour? Gas length?
If you dont like my methods, do your research and come up with your own.
@@harold1733 Thanks for the response. If you think that amount of effort pays off, good on you. I didn't say anything about liking or disliking your methods, just wondering how you arrived at your conclusion given all the variables. I agree that torque can play a role in accuracy, especially at extremes of high (overnight) and low (loose). That said, I built several rifles that consistently shoot 1/2 MOA on a sled with hand loads and I never had to take things to that level, especially with higher end barrels. But okay, to each his own. Happy shooting.
I use the German Torque spec of "gooden tight" when building my AR's and never had an issue.
My friend goes until his elbow clicks!
Exactly, you've made my point.
exactly this is the dumbest thing to be so autistic about. The fact that the dolos system exists proves this
🤣🤣🤣🤣🤣🤣🤣
Me too!!!
@@Steve42098 ran drills with the dolo system for months. Any consistent shooter will tell you its cabbage over time.
Eight minutes of math that gave me flashbacks to sweating out physics exams
Conclusion: "Don't make it complicated!"
Scullys Tie Exactly, that’s the simple approach.
Holy overthinking Batman.
You lost me as soon as he started talking about math. But I watched all of it. I don’t know why.
As an engineer myself, thank you for showing this correctly.
You definitely are not a real engineer. As a REAL engineer myself, I know, and YOU should know too, that no engineer ever did any real engineering to determine an ideal torque value. It's all just armchair enthusiasts jerking eachother off over made up shit. As long as you have the thing on tightly, it doesn't matter how much torque you apply.
I'm an ACTUAL engineer... you're both idiots.
@@samuelpalmquist2190 I too am an engineer and agree with the engineer above me.
At Deutsch Aerospace we "engineers" use to "sling ink on vellum" and actually included a page of mathematical data and conclusions.
The day any of you actually were required to take a class in slide rule and do the "math" is the true test of real "engineering."
The next year we were required to buy that TI SR-50 which was about $200 back then...I actually still have the thing.
Using applied force to cut, bend, shape and form various metals along with the blueprints for fixtures and molds, this shit is child's play.
Today we just plug in "netfabb" or "solidworks" and be done with it.
Still doesn't look as awesome as a shaded in inked vellum drawing framed and hung on a wall.
I’m the real engineer here boys. Take a seat.
I'm so glad you made this video because I've tried for years to explain how anything you use on a torque wrench that adds to the overall length gives an inaccurate reading at the head of the wrench (antique needle or dial & clicker)
You’re welcome, brother.
Math has never been strong point, but the way you explained it really help me to understand it. Now I want to go back and re torque the barrels on my rifle. Thanks for the lesson!
Paul Hughes You’re welcome brother, I’m glad it helped!
Stand on a scale, push up on wrench when 45lbs are added done.
Not really, must account for the length of the wrench
Very well stated and thank you for your time and effort. Having done warranty work for Colt, it was always a fairly large range that was acceptable and, most importantly, it could
never be exact because you then have to rotate the nut to the next possible position to clear the gas tube. Besides that, whether the threads are "wet" or "dry," anti-seize (which I do use)or not,
and have you compressed the threads a few times before you finalize the torque all come into play.
Do not use "anti-seize" that has metal particles, such as Neverseize or the copper stuff. Those bits of zinc or copper grab the aluminum and make it difficult to tighten smoothly. The barrel nut wants to move in jerks. Use a smooth grease, preferably with moly disulfide. This is ordinary brown wheel bearing grease for disk brakes. If you don't have that, regular grease gun type grease is fine.
Thank you! When getting in to this hobby it was immediately apparent that torque would vary based on type of wrench used etc. Leverage was the term I thought about based on point of force. The math is tough for me to follow but I really appreciate your explanation, I'm one of those worry worts that needs to know proper specs so I can sleep at night.
Crazy I just watched Hanson tighten a ballistic barrel down with an armors wrench to final torque . Said he doesn’t overthink it
So to keep it simple and ensure I understand correctly..
If I want to be as exact as possible..
I either keep the barrel nut wrench perpendicular to the torque wrench? And then it should apply relatively exact force to the setting on the torque wrench?
And if for some reason I prefer to keep the barrel nut wrench in line with the torque wrench then do the math that accounts for the extra length added?
Since the specs are typically a wide range, "don't make this an over complicated issue" is the final sentence said at the end of the video after a huge discussion and analysis. The answer could just be said in about 3 min= have the barrel wrench tool at 90 degrees oriented to the torque wrench so the length added by the tool does not affect the radial distance from force applied.
As stated, it was to provide visual proof based on the principles of torque, not just a simple statement that continues to be widely misunderstood.
Don't over complicate it. Lol after 10 min video with formulas. Just keep it 90 degrees.
All joking aside for those that don't understand torque and how you achieve it this is a very good video well explained and everybody should know the math. Remember what your math teacher said one day , math is going to save your life
NOW I remember why I dropped out of college algebra! (could not keep up with the professors). Some are meant to just shoot the dang thing.... Going elsewhere to look for 'the answer'.
People get so worked up between the the 180 or 90 degree offset. In reality, it doesn't matter. Unless you are adding several inches of length. For this specific application, the applied torque to the barrel nut does not require precision. Even if you do everything right, in terms of setting your torque wrench to a specific ft-lbs, you are applying torque a surface that is not smooth, meaning energy loss due to friction and heat. I am glad to see a video of an engineer that understands mechanics explains this topic.
Hoorah, brother.
Simple answer extension at 90 degrees always no math involved. Then the middle of the torque spec.
As an engineer from way back when we used slide rules and slung ink on vellum, even the mfg recommends that....
Most auto mechanics going by the Motors Manuals do the same...kinda an understood thing.
@@keithlucas6260 I retired as a Nuclear Mechanical Systems Inspector. Before that I spent many hours working on my own vehicles. Stickler for doing thing correctly. You might be surprised how many people don't have the same understanding you have.
@@calvinroyals6463 ....Thanks....went into the Air Force and was offered Colorado Springs AFA in '76 after I already had my degree....long story short was given a security clearance that's classified.
After an injury I was "retired" and got the job with Deutsch during this "leave of absence." Funny how things don't always go as planned.....ended up "slinging ink" for Bianchi Gunleather in Temecula and happen to be "that guy" who developed the locking welt holsters you see Safariland selling (John's old business bought his business).
I'm actually just retired from Baker Hughes as their top master toolmaker....found it more satisfying "turning handles." There isn't anything from manuals to CNCs, I can't setup, program or run and get $30 to $40 an hour plus overtime.
My "baby" I'm playing with now happens to be a 1948 CASE VAC utility tractor...
plus I have my own shop to "piddle" with everything in.
@@keithlucas6260 You are an example of what my cousin says. The cream rises to the top. I was a slow learner took me 20 years as Nuc 10 of them in Refueling before I put in for Work Leader to advance my career. Would like to have learned how to set up CNC. Everything I did was so far removed from my military MOS. Artillery men don't have much to do in civilian life. Funny I have made some holsters for friends and myself. All hand sewn too cheap to buy a machine. Well take care and be well.
Me using a crescent wrench and giving her a few good pushes and calling er good 😵💫
The one time I had a torque-wrench to tighten my barrel nut, the nut flared before I got to the 45lb setting. I looked at it thinking 'no way', and slid the handguard to it, where it stopped, unable to go all the way home. I did everything in the mfr directions, so I'm back to the fail-safe 'gut wrenching' method which has never caused me any issues in the dozens of times I used it on my own AR builds. I was able to grind the flare flat enough to allow the handguard to seat and it has been all good since, but I'm still shaking my head when I see that AR. I will say this, though...definitely clean the threads and use the specified grease or anti-seize, half tighten and loosen your barrel nut a couple times before your final 'torquing' or your torque is not what you think it is. I've been shown that by my armory friend when we were in the Marines and then he showed me a stripped upper where the threads looked like waves rather than threads. He said it comes from the aluminum characteristics wanting to grab and lock-up against the steel barrel nut when torque is beginning to be applied which causes friction/heat then the thread locking action premature to actual final torque. The '33' grease takes that out of the equation as it should.
The math geek in me thoroughly enjoyed this.
My brains just fogged up
Use the german method gudentight
Bottom line up front:
Use the torque wrench and fixture on the 90 degrees.
yea I have tried to explain to people that "the longer the dingus end the less the torque" for ages and some people don't get it.
if'n you don't believe it use a long extension with an impact gun to remove a lug nut... now try it with a short socket.
Thanks for the in depth explanation, I think ;-). The wrap up was excellent for an old mule packer who figured it isn't a Swiss watch I'm building.
This was really, really helpful and informative for us AR-15 beginners. Thank you so much, brotha!
You're welcome, brother! I'm glad it was informative.
Or: Just get the gas tube lined-up somewhere between 40-70 ft/lbs and you're good.
Best video I have seen on this topic. Thanks for making it so clear and easy to understand.
Just put the wrench at a right angle or the torque setting will not be accurate. That's it. If you want to know why, then watch this.
my brain just got torqued.
You hurt my brain with math.
Bill23799 Mission accomplished. The simple version is don’t overthink it.
Hahaha this comment 😂 I take it was the letters?
My GOD! my head hurts. Just tighten the darn thing with elbow torque.
LOL The whole [L(w) + L(e) x Cos(A)] / L(w) section is basically a correction that says mathematically: for the purposes of determining torque, the measurement from the center of rotation to where the force is being measured is the only part that counts. Which is very true. The Cosine of 90 degrees is 0 (i.e. 0% or none) and the Cosine of 0 is 1 (i.e. 100% or all). So L(e) x Cos(A) basically states that we're using some percentage of L(e) based on the angle and adding that to L(w) to get the true length of rotation, then dividing it by the length of the wrench to get the total applied adjustment for the wrench. Sometimes math is funny with regard to how true it is.
It's simply finding the length normal to the direction of the applied force.
Everyone says to torque it accordingly but tight is tight and even if you torque it you still have to go past the specs on some nutts to allow gas tube to pass through correctly i tighten my with out a torque wrench. When i torque to specs ive had them come loose and yes i seizen the threads. So fuck the specs. I know what works and i served 8 years in the marines also and know my shit.
You get it so this video wasn't for you, brother. It's for all those that don't understand the concept and incorrectly state the facts. Thank you for your service. Speaking of Marines, I just spent way too much time in the field with a staff sergeant but a good dude nonetheless.
Great Technical information. Thank you for your effort!!!
Great video! Speaks to my inner Engineer!
You're welcome, brother!
You have a window of 35 to 80 foot pounds. Torque to 35 loosen 35 loosen 35 loosen then set it to 40 and go until you can line it up or if it doesnt need lined up then its good. Its not a aerospace bolt on a space shuttle or tires on your car. Dont "Nuke" it like we said in the navy.
That's the entire point of the video.
Aerospace/Space hardware has very tightly controlled torque specs. They don't "nuke" it either. Over torquing aerospace bolts is worse than slightly under torquing them.
The only thing you're missing is a free-body diagram with a force-moment couple.
Great video very informative!
Thank you so much you help me alot with that.
The wrench is already 90 degrees. The diagram you shown is when the wrench is straight but the wrench on the barrel nut is already 90 degrees so you’re applying incorrect torque of 180 degrees. Keeping the wrench straight and the hook is at 90 degrees is correct.
so put the armorer's wrench 90 degrees with the torque wrench to get a closer to accurate value?
Interesting. I never knew that the angle of the the wrench, &/or attachment, would through off the actual torque.
steel nut connecting the steel barrel to the alum. alloy upper receiver.........30 to 80 pounds. there is a reason for the spec. to be varied so much.That would be that it doesnt have to be so tight to stay in the correct position. hence the locking tab on the barrel locking into the slot in the receiver....Its All Good......Just use a cresent wrench and turn it till its tight, problem solved.Dont worry about head space as it will only be 3-4 thousands at the most...that is the way its designed ...to be worked on in the battlefield with one or two tools....HAVE A GOOD DAY.
Good video, I like to know the rocket science behind these things, I just wish I could remember all of that.
omg wtf my head hurts
A lot of math and thinking for an application that's spec is 35-85'#
T=FL
F force in pounds
L length of the arm in feet
One could avoid trig by using a T-Square and measuring the length of an angled wrench. Keep the square normal to (90 degrees) to the barrel and read the length from the square.
No need for a calculator or trig tables
For non free-floated barrels, the barrel nut must be tight, but allow the gas tube to slide through. It must be left there, because it's impossible to tighten it enough to reach the next trough, regardless of the torque.
Not with some shimmy shims!!!
You need to account for the friction of the threads, are they lubed or dry?
What if it's dry lube? 🤔
This just might be the best explanation of the barrel nut math on the internet
Salutatins from GA! great vid! it made perfect sense to this math-head wanna-be builder. Thank you for taking the time & effort to explain this rationale....ps, your outtakes were enjoyable as well!
Thanks brother, I appreciate the feedback!
Ever notice that even after torquing barrel nut you have to clock the nut after for gas tube clearance. Excessive torque is not needed. Once assembled the gas tube prevents it from loosening. Much like a Carter key on a castle nut.
Oh wow, You're actually supposed to use shims. So then when you are at the appropriate torque setting then you are lined up for your gas tube. You definitely don't tighten to the torque setting then loosen it to line up 👀
Awesome video. I will definitely use what you taught here. I love the detail you go into, my type of video. What torque wrench are you using? I need to buy a good quality one. Thanks
Thanks brother, I'm glad it was helpful! That particular wrench is a 1/2" drive made by Tekton. I've had it for two years and it's been solid.
Pretty sure he's messing with us with his astronaut math then saying don't over complicate it lol.
Great video! Thanks for the illustrations and info.
In reading some of the comments left I see no one that seems less booooooord than I am after only 4.5 mins. BUt thanks for trying.
thats a bigfoot behind that tree
What is the nut tool you used there with the torque wrench?
As if half a pound of torque is gonna make a difference...ive been a mechanic for over 15 years and ive managed to calibrate own torque....💪💪...
Juan Carlos C That’s exactly my point in the video.
The torque specs are 30 to 80 because of the original spiked but that was used. You had to pass the gas tube between them to install it. Don't overthink it.
I've even removed the teeth on the barrel nut too make room for the gas tube & get exactly the torque I wanted.
There is no "correct" torque. It is what achieves alignment after 30 ft-lb.
Wish I would've paid more attention in math class!
Clint Boling Don’t worry, I fell asleep as well!
my head just exploded
That made my head hurt
Are you joking? This is to tighten a barrel nut. I thought this presentation was employing the KISS principle. I can see I was wrong.
I loved the sound!! Which music is that? Iam foreign
Not to be demeaning to anyone, but if you are having to listen to this video on barrel nut torque ......forget the AR and get yourself a box of rocks.
You're on a high horse
Says the dude literally listening to a video on barrel nut torque.... eat shit bro
Outstanding commentary Professor Lonestar Patriot. I had to stop the video and go get my slide rule for the first six minutes of the video. I called my grandson and had him watch the video also. He offered me his Texas Instruments TI-30Xa Scientific Calculator LOL, LOL, LOL. I was able to follow you on the second half of the video easier. LOL (3X) again. 🐢🇺🇸🐢🇺🇸🐢🇺🇸
Haha, that's a name I have yet to hear but thanks brother! If you're having to reach for the TI-30X, then you're already overthinking it!
:I enjoy your commentary just having fun. LOL I 🐢🇺🇸🐢🇺🇸🐢🇺🇸👍
Anthony Shepard I knew you were and thanks for tuning in!
Ah! It all makes sense now.
Physics is interesting. Thanks for the info.
Could you have flipped the extension that was at 90 degrees to the wrench so that the center of the nut was inside of the center of torque wrench to get just slightly less torque than the setting on the wrench so you don't have to worry about over torque?
Just lower your torque wrench if your worried about over torquing. The torque is a VERY VERY wide margin on these barrel nuts.
That's why there are plus and minus tolerances on torque specs. Close is good enough in most cases, plus no 2 torque wrenches torque the exact same. _Never_ figure that you are torquing to spec, always figure you're n the ball park. When in doubt, use another wrench to confirm.
@@F16_viper_pilot Leverage on the hand is not leverage at the socket. Two different things going on there.
If I shoot a shotgun shell in an 18" barrel, and an identical shell in a 28" barrel, the amount of pressure never changes, but the velocity will.
Same as with a torque wrench. The socket pressure will not change, only the felt pressure used to get it there will.
Give me a lever, and I can move a mountain. But the weight of the mountain itself will never change.
Changes on torquing come from the extensions, not the handles. The longer the extension, the less torque is applied through metal fatigue, stress, and twist.
But even that is minimal.
Great video!!!
Darryl Johnson Thanks, brother!
OMG. at 78 years old I had to write all the figures and numbers down - now am ready to install barrel BUT can’t find my notes or my i-pad ::::: if I can find my truck keys I’ll go to a gun shop.
Makes sense. 👍🏼
Thanks, brother.
A wrench and a hammer is the direction I went in after the video 👍
Thank you, I had a hard time finding this information, i finally understand the correct way to use a torque wrench, its scary how many low intelligence people are playing with guns.
You're welcome, brother.
With the new math 1+2 =4 so I am sure 90 degrees is really only 85%of the old 90 or is that 95% of the old 90 degrees. I think i will just stick with Gudentight.
Tork rench. Size that fits in the AR rench
What in the haberdashery and hemoglobin!
If I could do math I'd be a fighter pilot lol
Cue the Top Gun theme song.
Dear god, tighten it up already,
would ya? Holy shit!
Great info! Bottom line keep that angle 90 degrees. 🐼🐼🐼
You beat me to it, although I do deal with angle variations for my occupation.
every video I have seen; some kind of lube is used on the barrel nut/receiver thread.
the addition of lube changes the torque value? reduces the torque by about half. why does no one addresses this fact.
It's the reverse to where lubricity will provide an increased applied torque; however, for this application with an anti-sieze grease, there's not a significant increase in applied torque and it does provide a more even distribution to the threads. That's why a median torque value simplifies any anomalies to where it's still within acceptable tolerances.
As a mechanic, I’ll tell you that’s not the case at all. Applying lube to a fastener does not double the applied torque, not even close. It may increase by just a little bit since the friction coefficient is reduced but nothing critical at all.
Tim Oneill , you are correct. However it would be more appropriate to say that clamping force and fastener stress go up as friction goes down with the same amount of torque.
This equation relates torque to clamping force:
T=KFd
where:
T=torque
K=friction coefficient
F=clamping force
d=thread diameter
This is a general equation for preload torque on a solid fastener. The following links explain preload torque and friction better that I can and also why torque is an awful method for retaining fasteners. I would like to add that the type of lubrication is part of the torque spec.
ua-cam.com/video/lsCyAvTqcNE/v-deo.html
ua-cam.com/video/XMjQTl_x3fc/v-deo.html
ua-cam.com/video/fbvf4vMp4bk/v-deo.html
The 30 to 80 ft. lbs torque spec is based on the use of aeroshell 33ms grease. It doesn't change much for other greases. Non-issue.
Good information but a little confusing, I would think your angle would’ve taken from center axis of the wrench head and the centerline of the socket on the adapter/extension regardless of the shape of the adapter. It doesn’t make sense to square off the edge of the adapter, there is a frog in Alaska that freezes during the winter and while frozen the frog stops breathing, his heart stops beating, his palms are sweaty, knees weak, arms are heavy there’s vomit on his sweater already, moms spaghetti.
Just remember the length for the moment arm must be normal to the direction of the applied force.
You didn't even show us the geissele rail that came with that barrel nut lol
He lost me at "numerator" 🥴
All good my friend have s great day I will subscribe to your channel
Thanks brother, I appreciate the support!
I was told there would be no Math involved!
Ooooooooooooooooooooooooooooooooooorrrrrrrrrr........... you could just tighten it. 🤷♂️
K.I.S.S. = keep it simple simple !
Do you know how many people you just destroyed?
Here is how it works, place the barrel nut ,use a little locktite, torque the barrel nut down between 35 and 80 foot pounds, back it off a few times too stretch the threads then finish the final torque and you're done
Guy Green I have an ar 15 pistol upper from ground zero precision. I’ve been looking around on how many foot pounds to torque it. Do certain company’s have different torque specs or does the 35-80 ft lbs work for all ar 15 builds? Plz help
@@brandongarcia2688 30-80 ft. lbs. is pretty standard. First of all, don't use loctite. Get yourself some aeroshell 33ms. It is less than $10. It has anti-seize and anti-gaulling properties. Coat the outside of your barrel extension with a thin layer. Coat the inside of your upper where it meets the barrel with a thin layer. Set your extension at 90 degrees to the torque tool. Set your torque tool to 30 ft. pounds. Torque it to that spec. Break it (unscrew it) using a breaker bar, not the torque wrench. Repeat that torque spec 2 more times, breaking it two more times. On the fourth go, you are going to set it to about 40 ft. pounds and tighten it. If it is properly clocked or you have a barren nut that doesn't require clocking then you are done. If you need further clocking, set your torque wrench to a higher value like 60 ft. pounds and just keep moving it ever so slightly until it is clocked correctly. Keep repeating until it is clocked but don't go over 80 ft. pounds. The only reason I incrementally increase my torque for clocking is so that I know about how much it is torqued. Happy building, friend.
One thing I have learned about torque. There is no need for it, everything I have torqued to spec has backed off or loosened up over time which is why they always tell you to torque again. If you tighten it as much as you can without straining then it is tight enough. Torquing is overrated
For all you Apple Products guys, App Store has a free app from Snap-On , Torque Source. Plug in the numbers and it give you the torque needed. While math is good, apps is better !!
I was told there would be no math.
Dont nuke this. The range is 30 to 80 ft lbs torque. Thats 50 ft lbs. Not going to matter much as long as its in between.
Hoorah, Seabee. That's the exactly my underlying point.
@@thelonestarpatriot hoorah