Most people still think that loctite is there to increase the torque needed to break lose the bolt or screw. This is not what loctite is for, it is to prevent the fasterners from coming lose due to vibration or use. It simply takes the place of a lock washer.
Thanks! Loctite resists vibration by "gluing" the fastener which also increases the torque required for removal. Measuring the breakloose torque is easier to measure if you don't have a vibration setup. 😎
@@HacksbyDad the problem is that the rigidity of the loctite is so much lower than the steel, that it is not deformed enough to help resist during the break loose test. I suspect that the two work sequentially, not simultaneously during your removal test. First you break free the torqued nut, then you shear the glue.
@@WalterMelons Take a look at Hacks by Dad's other videos, he tests lock washers. They are better than nothing! Surprisingly split washers seemed to work better than toothed ones. From my experience if you ship stuff without lock washers, you'll have nuts all over the bottom of the box, but not with lock washers. Especially when it goes by truck!
You are absolutely correct. When a nut is torqued down, one side of the threads are compressed leaving a wider and wider gap on the other side of the threads, the more the nut is torqued. This squeezes the locktite out of the compressed side of the threads and into the widening gap on the other side of the threads, resulting in slightly less than 50% contact area than before torquing. There are different bolts with different thread types. Not all threads require torquing down till you feel metal flex. 🙄 The threads that do require this, also require replacing after every removal, (as the threads are now bent, smashed, spread, and weakened, and bent back the other way from removal). Like bending wire, this makes threads weak. Tips for fastening hardware! 1) Know your hardware’s specification ratings, (they all have them: weight limit, shear limit, torque limit, etc.). 2) Don’t ever over torque hardware past it’s rating. 3) Use the correct adhesives, and or locking hardware for the job. Red is not the same as blue, know the difference and their application limitations. 👍 Love your channel! Your videos are Spot On!
The fasteners require replacement when torquing that hard because the surfaces experience very heavy sliding loads without lubricant and you get surface galling which seizes the fastener. For depth of thread beyond perhaps 2-3 turns of thread, the cross sectional area to loading is larger in the center part than the outer and the angle at which the loads are applied by the threads means you will snap the bolt and never rip the threads clean out. It’s the same reason you can’t use an impact driver to remove heavily torqued bolts. If you remove them slowly, it’s fine. If you explode them off with a high power impact wrench the heavy load and fast speed friction weld the fastener in place and it seizes.
Your experiment is correct. But: Nuts and bolts are not designed to transfer torque. They are designed to pull, and nothing else. So what do you think, what works better in transferring a pulling force, a cured and then compressed polymer or steel? Spoiler alert: steel. Nuts and bolts are used to press surfaces together, for this task they need to be torqued down. Changing loads can cause bolts to rattle loose, and here is where adhesives come into play. They are not designed to increase any torque. Their single one and only use is to keep bolts from rattling loose. Nothing else. And by the way, torquing a nut or a bolt down is not intended to keep it tight. That's accomplished by thread geometry. The job of the applied torque is to generate the designed pressing force on the working surface of the workpiece.
This exactly. Preload and clamping force are the only engineered parameters, torque spec is just a translation of those parameters into an assembly step that's going to produce repeatable results without complicated QA steps.
Lmao, you realize that there are MANY other applications for threads than applying clamping force? Just as there are MANY applications for Loctite where it is holding the threads in the desired position with no assistance from anything else. So, you are basically entirely wrong.
@ke6gwf obviously, you have no basic understanding of the different types of threads and their applications. In the video it's solely about standard bolt threads, which are designed for clamping force only. I'm a certified technical engineer in Germany, my studies included threads, securing threads, thread locking adhesives, thread applications, tightening torques etc. What are your sources?
@@andrebartels1690 I'm wondering if he has a point, although not well stated, in that threads can be used for adjustment mechanisms, simply to move one assembly relative to another, where the threads are essentially a lever, there is no clamping force involved, and friction is usually an adequate mechanism for keeping the assembly stable in use. Extremely common of course. Perhaps there are other categories.
I saw my grandpa torque a nut down then take a flathead screwdriver and hammer to bend the thread on the bolt once. It worked on his box scrape (it gets lots of vibration). That was back in the 70's and he didn't have a second nut to lock with.
That's basically what mechanical staking is. You deform the metal with a punch or chisel so that it physically can't unscrew without bending or breaking the deformed metal
Surface prep is critical. When you're using stainless or plated metals (less reactive metals) thread lock primer can make a difference. They also have special thread lockers for less reactive metals. If you get it right, breaking a bolt loose that has the permanent thread locker on it is really difficult and can damage the bolts. Just last weekend I had to disassemble some stainless parts with the permanent thread locker and we needed to use heat to get some of them to budge at all. Which brings up, if you need to disassemble some properly thread locked parts, heat will make the thread locker release significantly reducing how much torque is required.
@@NathanailStiversit's not, because if you refer to the actual Loctite technical documents you will find that while Activator is Recommended for zinc plated, but mainly to speed up the curing time, but it will still cure on them, it just takes longer. Also, that style zinc coating is so thin that it should still get some contact with the steel underneath, especially on cut threads.
I've used threadlocker to secure dovetailed metal joints into place, no torque involved whatsoever. Had a pistol front sight that became loose and liked to slide back and forth making it completely unreliable, but Loctite froze it right in place. Also if you ever want to change the forend on a Henry lever action, the ring holding the magazine tube under the barrel is attached via dovetail joint that must be punched out. If you do this it will inevitably loosen up, and once again Loctite is your friend.
You don't get much extra brakeloose torque if you use "loctite and torque" because if you have enough force to break the loctite then you've already far surpassed the requirement for the nut on torque alone.
This would be my theory as well. The Loctite and bolt preload are two different mechanisms being acted upon by the same breakaway torque. It would stand to reason that they'd both fail once the higher breakaway value is reached.
preload exists not to increase breakaway torque, but to reduce fatigue in the bolts. loctite exists to increase the amount of time a torqued joint stays torqued after experiencing vibration and live loads.
The preload provides an amount of clamping force required for the joint. Depending on what is being held together and why, that preload might be crucial to the function of the joint. For example brake discs on bicycles. What holds them in place is friction from the preload of the bolts. Without enough friction, the disc slides and bolts shear off under the type of load the assembly is otherwise rated for.
Your hypothesis makes sense. I have found the same results with wood glue on wood. If I titen the wood together too much, all the glue squeezes out, and the joint fails to hold properly.
Here's what I was told in engineering school, and what I believe from decades of experience. Some of the other comments have alluded to some of this. The loosening of bolts in service, in almost every application, is always caused by cyclical lateral movement. Either cyclical mechanical forces between the parts, or cyclical differential thermal expansion. Sometimes it happens at a near-microscopic scale. There's always nonzero clearance between the male and female threads, and each time there's any lateral movement of any kind there's also some tiny amount of rotation unless it's prevented somehow. Rinse and repeat, and eventually all preload is lost. Split lockwashers do essentially nothing to counter this, and in many cases will allow a bolt to loosen faster than no washer at all. That's a whole other topic, too much to get into here, but they're a placebo in general. Internal or external toothed washers are much better, but still of limited utility. The Nord-Lock system is very effective, but only if applied properly. They can be done wrong by untrained personnel and then they're useless. I avoided using them, even when I could give detailed instructions in a manual, because it would only take one person ignoring or misunderstanding the manual and it would be worse than not having them in the first place. The main function of a liquid locking compound is to fill in the clearance between the threads, so there can be no lateral movement that would start to loosen the threads. There is some adhesive action, but that's secondary. You're doing some good science and doing it well, but breakout torque is not really relevant. It doesn't simulate service conditions, I can't think of an application that creates an active torque trying to loosen a bolt. (That would be a VERY poor design!) Not to say this isn't good work, but it doesn't simulate actual service. Your vibration testing in other videos is much more relevant. Locking nuts of various types are often a good answer. Nylon inserts (aircraft nuts colloquially) do a good job generally, giving an effect similar to locking compound. There are nuts on critical connections on my motorcycle, the axles for example, that have spring steel inserts that clamp down aggressively on the last thread. No matter what happens they will make it hard for the nut to vibrate loose, even if the preload is lost. I assume those are pretty expensive nuts. Bottom line, in virtually every case, you're better off with Loctite or something similar than without. I have been using the orange Permatex orange for a few years personally and I like it. It claims to be as strong as red Loctite, but still removable with hand tools. I don't know about that, but I think it's better than blue Loctite. It has been working for me.
I worked at a heavy equipment dealership years ago. A coworker was changing out a wheel loader cutting edge, he didn’t finish the job and went for coffee. When he come back he was unable to tighten up the mounting bolts with his impact gun. It was the dealerships practice to red loctite the nuts on, he left all of them loose. After seeing this video I now understand why those nuts were immovable! He had to torch off all the brand new fasteners and try again lol
Torching them off was a bit excessive - red (271) and green (270) loctite needs heating to about 250C to release it but you don't need to torch the fasteners in half.
As I'm sure many others have already pointed out, Loctite is not to make the but tighter, but just to help it hold and not back out in applications with vibration.
There is an optimum bond line thickness for adhesive joints. If it is too thin, you get lower strength. Many commercial adhesives contain spacer beads that are about 0.008" in diameter, so that when you assemble the joint you cannot press the adhesive too thin. I'm a big fan of threadlockers and keep half a dozen grades on hand for various applications. No doubt they have saved some expensive parts and possibly prevented me from having some crashes.
A very nice job on the experiment and I agree with your reasoning. Just as blood cells are shaped with a concave surface on each side, surface area (or in this case contact area) is the key to the solution. More is less and less is more is the way of most things.
Another thing to keep in mind is that bolts stretch as the torque is applied. Try a more realistic loading scenario for the bolts. Try adding some material to be under the clamping forces of the bolt and nut, and with/without loctite.
Interesting. Good insight on the analysis. On a separate note: stainless steel requires a primer to cure. Rep from Henkel shared a story from a dairy farm that had concerns with Loctite and stainless steel.
@@HacksbyDad Be sure to read up on the issues with galling and stainless fasteners. This is why *lubricants* are often recommend on stainless fasteners.
I can verify, properly used primer definitely helps. Just last weekend I was disassembling and re-assembling stainless parts and we were using primer. We applied the primer, let it dry 5 minutes (according to directions), I coated all the bolts with thread locker and spun them finger tight and left it as I did some other assembly work. When I got back to the finger tight bolts, they were already starting to bind up from the thread locker curing due to the primer.
They guy at the store told me Loctite is activated with absence of O2 -- he said a guy combined two semi-full bottles into one, and with the bottle being full, the whole bottle turned into a rock. Just passing along.
I remember reading something about how when you touch the tip of the bottle to the metal, it can set off that reaction (not a chemist here so I can't explain the deets) to eventually solidify the bottle. Possible one of the bottles was "contaminated"? I know I've had to toss out old bottles that solidified.
i bought a bottle of cyanoacrylate and used a little then put the cap on, it turned into a rock in weeks to months. the only way to save cyanoacrylate it is to discard the cap and put hot glue over the hole, polypropylene will not work to seal it.
Hey man, just so you know. A bit heavy handed on the loctite, had a training seminar at work by loctite as I'm a truck mechanic. Turns out too much loctite will more likely break free compared to the correct amount. Around half a drop on an m8 thread is plenty.
Here’sa good one: big,big punch presses have 4 huge bolts to retain them top to bottom. They heat these long bolts up really hot, spin the nuts tight. And let it cool. Talk about tight!
That is a good one! I wonder if I can do a small scale experiment. Maybe heat a bolt, insert it into a jig, finger tight a nut, let it cool, and then see how much torque it takes to break loose the nut. I’ll add this to my list and think about it more. Thanks! 👍😎
@@SantiagoArraga I think the point is that the length of the heated bolts would shrink, thus tightening the joint which would, I assume, increase the torque required for loosening.
This is how old-school hot riveting works. Heat the rivet to cherry red, insert in part, mushroom the second end, and when they cool they shrink lengthwise and generate tremendous clamping force.
Bolts, nuts and thread systems are there to apply a clamping force to an object. Like the tread in an engine block and the head bolt apply a force that sandwiches the head, head gasket and surface of block. We try and achieve the correct clamping force by applying a known torque to the fastners which should achieve that clamping force, other ways that can be used to set a reliable clamping force are to measure the elongation of the bolt as it is stretched by the clamping force. With just the nut and bolt solution without any extra locking mechanism the system is reliant on the friction within the threads and the contact surface of the nut and bolt on the clamped object to prevent it from undoing itself. Differential temperature expansion, vibration or impacts place momentary large forces on the fastner system that can overcome that friction and start undoing the nut. Without any other mechanism the clamping force applied rapidly decreases and the fastner loosens quickly. Spring washers better absorbs the momentary forces without the fastener loosening. Liquid threadlock applies no friction within the threads when doing up the fastner allowing a correct torque to be applied for the clamping force required, and then hardens inside the threads greatly increasing the friction within the threads increasing the torque required for the nut and bolt threads to move, while not significantly changing the clamping force.
My guess is that you will see much stronger results with blue, or maybe green loctite. Red loctite is made for high bond gaps, while green is for very small bond gaps. Blue is in the middle. You are likely squeezing the bond surfaces so tight that the red loctite can't actually form under the correct gap conditions. This is something I have run into with metal/carbon fiber bond surfaces, you can greatly improve the bond strength by blending the epoxy with glass beads with diameter equal to the exact bond gap the epoxy is made for.
I would assume the strongest bond would be it. So 1 or 2 = 2. If you went higher torque beyond what threadlock can offer, it probably would be that. Treating threadlock as glue .
Awesome Video, easy to follow and logically performed. I can’t find any fault with the test you performed nor with the conclusion you came to. When I heard that people were complaining that you HAD to torque a bolt for Loctite to work I Immediately was like “What you(those ppl) smoking foo!” Most everyone should know it cures in an anaerobic environment which is why they sell the bottles only half full … cuz it needs the air in the bottle to prevent the fluid from kicking off in the bottle. I had never heard anything about needing to torque to achieve a suitable environment for that to occur, most anyone who has used more than 1 tube has almost certainly had a situation where they needed to temporarily hold the position of a nut or bolt in place and used a dab of Loctite to achieve it, had mechanical torque been required to achieve that environment it would never have begun to set up. Logically if you just think about it, even a relatively small amount of water or oil are capable of filling the gaps between mating threads of fasteners thus displacing the air while doing so … with the only oxygen present being on the small openings on the two ends of the threaded spiral the Loctite in the middle farthest from those opening begins to meet the criteria for driving the reaction. I would venture to guess that there is a threshold involving volume to surface area contact with oxygen that needs to be met to kick off the reaction which probably then keeps getting driven forward.
I think it is only preload that keeps a fastener from coming loose. If preload goes low during a vibration or force change, the fastener has a change to come loose. Loctite and other methods (spring washer, nord lock, nyloc nuts etc) only prevent the fastener from falling out after the fastener has come loose. Proper torqued fasteners in a stiff construction don’t come loose.
It’s important to note the type of failure your adhesive is under (ie. cohesive/adhesive). Assuming your loctite isn’t expired, you’re likely facing adhesion failure to substrate, and this is always due to poor mechanical adhesion as a result of contaminates. Always always always clean your threads and wipe dry with solvent before applying adhesives.
I had an OLD dump truck and one of the air controls for the tarp (Aluminum arm threaded in steel stripped out) Red loctite and stuffed it in the hole like gluing a plastic model together. Still works to this day with the 3rd owner of the truck. In my situation it was a quick fix that worked like metal glue. Big gap and not squish out. Nice vid!
Because Torque does not add, once you “break” the first barrier, the second one is the only thing that keeps holding on to it. It’s a spring, slipping at a certain level, not two springs supporting each other.
Use loctite 242 instead of 271. 242 makes a gummy whitish substance to help with vibration loosening. 271 needs heat to loosen after a long time being used
Great testing methodology! If you're going do to additional tests in the future, it would be interesting to see how Locktite 290 (wicking-grade threadlocker) works in practice with similar testing. I think that can be applied by first torquing the nut dry and then applying the wicking treadlocker. I would be seriously disappointed if it didn't clearly increase breaking torque required after curing.
All depends which one you use. There are many different red thread lockers. Some don't really dry at all. Or dry but are easy to remove. Others dry very hard. Each is use for a certain situation. Depends on the type of bolt. What the bolt is made of. With the bolt be on a exhaust or engine. Where it faces high heat. And heating and cooling. Or is it in a standard temperature location. What other elements will it face. Cold,wet, salty,( road salt) or rusty location. Torq is not required at all. I use it to lock a set screw. At a set depth. And it with stands daily heating and cooling on a special exhaust application.
So next question since you've figured this part out... Does Loctite 271 work best with any particular metal coating/plating???🤔 The two other platings/coatings I am specifically thinking of are "Yellow Chromate" and "Black Oxide"!!!
Don’t forget to account for Class of threads Class 1, 2, 3 (A&B) this will effect squeeze out significantly, as the closer tolerance Class 3 will have less room for thread locker Also would like to see your test for VC3 and other acrylic compounds! 😊
in Poland we say: klej trzyma gdy go ni ma, which translates to: the glue holds when it is not in there. Meaning, glue works best when it is squeezed out almost entirely from between the surfaces. It’s funny to see this test, which shows that Loctite is not glue, meaning it behaves in a counterintuitive way
I'd be interested in the results with different thread tolerances. Most nuts and bolts are a 2H fit. By the time you get up to a 6H fit, there is no place for the thread locker to occupy. Also maybe a test on Acme and Buttress threads?
Loctite is not adhesive in the traditional sense. It is essentially a gum that fills the thread pathway and increases shear friction as the threads rub past each other. Just like a nut with nylon insert. In this way you can see why a loose nut having two bearing surfaces (both sides of the thread V shape) with a friction increasing addative requires more torque than one side of the thread V plus metal on metal contact for the tight nut.
One has to remember that the question of how threadlocker is chiefly intended to be employed is a different question than asking whether it will or won't function in some particular application. "Loctite isn't _supposed_ to be used that way!" Maybe. But if what it will actually do under those circumstances is what you want, well, the Threadlockee Police aren't gonna kick down your door.
While loctire's PURPOSE is not to "increase" torque required to remove a fastener, in most instances (especially the red stuff) it actually does! Anyone working on a device on which someone had installed relatively small fasteners using loctite red, immediately is aware that removal torque has been greatly impacted. Its bond is such that, unless heated, its not uncommon to snap the heads off fasteners, or "pull out the threads" from aluminum and other soft alloy materials. The greatest impact that loctite makes to removal torque is from its adhesive bond with the fastener...that's why the "loctite + torque scenario actually provides for lower removal torque than loctite alone...in effect, with increasing torque the fastener squeezes more of the loctite from between the applied surfaces resulting in less bond strength. In effect, the "thickness" of the loctite between the fastener threads is reduced, which in turn reduces the strength of the physical adhesive bond. So.. to summarize: loctite's ability to increase removal torque is just a "by-product" of its curing process. In reality, it is simply a "chemically resistant" adhesive, that by filling in voids between threads (and also providing some degree of a "gluing action") results in a fastener joint that is less likely to loosen due to vibration or heat/cold cycles. In some applications. (Semi-truck lug nuts for example) the fastener is massively torqued when installed...and loctites ability to increase removal torque is such that it only adds a tiny increase to the lug's overall removal torque value (if someone actually used it in such an application). Of separate note: most all loctite formulas require some degree of copper in the surfaces being bonded in order to cure properly. This why loctite (or equivalent) "primer" is necessary when dealing with stainless steel and certain other potential fastener materials and plating treatments. Without it generally "remains wet" and doesn't set up to perform a bond.
According to Henkel, Loctite is not an adhesive. Yes, there is some 'adhesiveness', but it works by taking up the space in the thread. This is why you are supposed to be generous with its use. The initial breaking loose is probably the initial crushing of the solidified Loctite. This also why torqued and untorqued joints have the same break loose torque. Also, Loctite acts as a lubricant. This means if you torque to the same amount as a dry joint, you are getting higher preload in the joint. This will be throwing your test off a bit.
I found it fascinating, that when working on newer vehicles, sometimes replacement of a component requires new hardware replacement. Usually the nuts/bolts are simply ordered as a kit. Sometimes the composition of the bolts, maybe are made of magnesium, aluminum, etc (some material that now makes it torque to yield, or stretch bolts). When you get this new bag of hardware, i found it fascinating that the manufacturer preapplies loctite to the threads of these new bolts/nuts. Purpose of this post, is to dig into applying any version of loctite, BUT, ALLOWING THE PRODUCT TO FULLY DRY FIRST (probably a 24hr downtime), THEN ASSEMBLE. I would love to hear some feedback regarding this.
Manufacturers don't like to apply liquids and glues on the assy line. Of course, if they're using threaded inserts with a locking feature, the replacement bolts don't do much better than the original one.
@@tubergonz for example, bmw. I remember their parts department had a display on their parts department counter. It demonstrated the weight savings of opting to use magnesium bolts and fasteners, over the traditional steel. The weight difference was obvious. Don't really think it's fair to say, that's why they started applying thread locker, due to the tensile strength just isn't enough to simply torque the magnesium or steel bolt to the same value. The magnesium stuff probably has a lower torque spec, which necessitates the need for the thread lock application.
@@sidewayzmike I'm going to have to look further into magnesium fasteners. It's kinda funny but aircraft seats don't use them much at all. I guess its cost.
Perhaps the problem is that Loctite has some flexibility to it so even the torqued nut you start to break it free before the threadlocker holds it back.
Clean the nut and bolt in acetone before adding loctite. I have NEVER been able to remove a bolt that has red loctite without heat from a propane torch. And I didn't use zinc plated bolt or nut either.
Thread locking compounds are fine when you do not want stuff to fall apart. They are an absolute Cnut when someone (like me) tries to work on your car, and it is literally glued together and won’t come apart. Ever. I had to replace the engine torque bar (bottom middle engine mount) on a 2016 Ford S-max, the rubber bit had failed. . . . I had to remove the subframe from the car, and use induction heating to heat up the threads in the subframe to melt the excessive amount of thread-lock. The bolt was going to snap. 20 seconds of heat, and it came out with no effort. Then I had to re-tap the subframe to remove the thread lock. It was not a case of ‘we do not want it to fall apart’ as a case of ‘we do not want it to ever be taken apart, buy a new car.”
Ho braddah, yeah i think youre right about loctite filling the gaps. Its more like a nylock. Rust also works. Anything to fill the gap in the threads. Check out nordlock washers if you wanna get fasteners locked up. Nothing like them. You'll think ever bolts gonna snap during disassembly. Dig in to bolts stretch and yield %. When you factor stretch, the long the fastener, the more turns it takes till the tension is removed, you may find loctite to be more effective, as its crystals bind in the threads more. Try bolt with a long spacer tube, like 3" long bolts, so you need like 1/2 a turn or more before the tension is removed. Fastening can be a deep dive into materials science.
Interesting! Now visit the possibility that the lesser force required to loosen the torqued samples are not due to squeeze out of the threadlocker but rather due to mechanical forces already pushing the nut/fastener towards the loose side. When you press something on a surface there's an opposing force generated which would aid the loosening of a hypothetical nut on a thread. Just a theory. P.S. I don't see how you'd squeeze out threadlocker from threads that are not compressing while you torque the nut. Even so, the same amount of threadlocker would remain in the next set of threads and, ultimately, squeezed out paste would be visible at the edges (which every time I apply threadlocker, it's definitely not there). Maybe if you put more we'd be able to see it.
Did you ever try allowing the loctite to dry on the threads before running your nut down the thread and torquing to setting? Maybe try different dry times too 🤔🤷🏻♂️
Thanks! Loctite threadlocker cures in the absence of air, so I would need to figure a way to remove the air. Maybe wrap in plastic wrap? Here's a video on different cure times... th-cam.com/video/Xmkc4mDVw3w/w-d-xo.html 👍😎
Thread Locker is not about torque. It's about keeping the fastener from loosening. Similar to what nylon lock nuts or lock washers do. But more reliable.
Does it matter in real life how much prevailing or breakaway torque locktite provides when the nut hasn't been torqued? Who uses it in that matter? Maybe something that is shipped while loosely assembled and the final torque is applied later? I've seen loosely assembled fasteners come apart due to sympathetic vibrations during shipping.
Thanks. I don’t think it matters much. In my opinion, Testing loose or untorqued nuts removes a variable and simplifies the testing process. It also gives higher results that look more impressive. 😎
when you torque the nut, it squeezes out the Loctite, so you have less glue between the threads. anyway you need to torque it to the correct specs to begin with
Bolt ( seized ? ) by ANY Loctite™ ... heat it up ( you MAY have to use a blowlamp ! ) ... instant release😝 ! and this works for all other companies , liquid " thread lockers " ..( tried - n - tested ) .... DAVE™🛑
Excellent video and excellent detective work! Your results seem compelling. However I'm struggling to understand why "squeeze out" reduces the strength of Loctite so dramatically. One would think that when the metal faces are pressed together, there would still be a very thin layer of glue remaining. Why doesn't that thin layer provide bonding strength?? I believe many other adhesives bond just fine when cured under pressure. Why not Loctite?
Best Anaerobic curing : Reactive metals like iron, steel, copper, or brass are ideal, basically a catalyst. Narrow bond gaps, clean surfaces, temp 68f to 86f, oxygen or lack there of. Non optimium is opposite of this.
I've seen several comments and the video itself state that a lack of oxygen is required for an anaerobic thread locking compound to cure. I believe that is incorrect. The "anaerobic" bit doesn't mean the reaction needs a LACK of oxygen. It only means the reaction doesn't NEED oxygen.
Not a huge fan of the stuff. I use 3m yellow weatherstrip adhesive and it has about the same strength as blue 241, and won't cause issues where ive seen it corrode fasteners. Of course the red is needed for the strength ,but most applications the 3m works great.
As soon as I saw the specs im the beginning my theory was surface area is bigger on a loose nut. I cannot however see how the formula is relevant in any way
At the end of the video, I think you have the graphics and the text combination reversed. 65% should be shown in combination with the tightened threads.
Hammer some flats onto the bolt thread then run the nuts onto the flats. JB weld the rest and test that. Weld the end of the bolt or stud to retain anything that could fall off. Welding will work. Stop playing with bs in tubes. Mig weld. You could also wrap wire around the treads to retain the nuts..
@HacksbyDad Good test, and the Nord-Lock video and chart confirming your results is a nice touch! Surprising that wet locktite has more friction than steel on steel. Perhaps there is an additive with this in mind. Thanks!
Thread locker is not a glue. It fills gaps between threads therefore prevents cross axial movement nut to bolt under dynamic load. Gluing is a side effect😊
Thanks! Threadlocker by definition is an anaerobic "adhesive." In addition to filling the gaps, it also adheres to and grabs the surfaces to minimize movement. The breakaway torque is a simple way to measure the adhesive strength of the threadlocker. I'm working on a new vibration test to put various threadlockers, lock washers, and lock nuts through their paces. 😎
@@andreystepanov8643 Yup! You read my mind! A DIY NAS vibration test. The Junker test doesn't seem as realistic. Here's my first version of the DIY NAS test... th-cam.com/video/lwtUWB2TIYA/w-d-xo.html th-cam.com/video/4H-HOHZ3chA/w-d-xo.html The rig is too cumbersome. My next rig will be more light-weight. 👍😎
Check out all of my Nuts and Bolts videos in this playlist... th-cam.com/play/PL_WcGw5s6Cq6YK_s-NNne1838j25ijmii.html
👍😎
Most people still think that loctite is there to increase the torque needed to break lose the bolt or screw. This is not what loctite is for, it is to prevent the fasterners from coming lose due to vibration or use. It simply takes the place of a lock washer.
Love your vids by the way!!
Thanks!
Loctite resists vibration by "gluing" the fastener which also increases the torque required for removal. Measuring the breakloose torque is easier to measure if you don't have a vibration setup. 😎
Lock washers are a joke. All of them will loosen with vibration. Only things worth it are nylon lock nuts or thread locker.
@@HacksbyDad the problem is that the rigidity of the loctite is so much lower than the steel, that it is not deformed enough to help resist during the break loose test. I suspect that the two work sequentially, not simultaneously during your removal test. First you break free the torqued nut, then you shear the glue.
@@WalterMelons Take a look at Hacks by Dad's other videos, he tests lock washers. They are better than nothing! Surprisingly split washers seemed to work better than toothed ones. From my experience if you ship stuff without lock washers, you'll have nuts all over the bottom of the box, but not with lock washers. Especially when it goes by truck!
You are absolutely correct. When a nut is torqued down, one side of the threads are compressed leaving a wider and wider gap on the other side of the threads, the more the nut is torqued. This squeezes the locktite out of the compressed side of the threads and into the widening gap on the other side of the threads, resulting in slightly less than 50% contact area than before torquing.
There are different bolts with different thread types. Not all threads require torquing down till you feel metal flex. 🙄
The threads that do require this, also require replacing after every removal, (as the threads are now bent, smashed, spread, and weakened, and bent back the other way from removal). Like bending wire, this makes threads weak.
Tips for fastening hardware!
1) Know your hardware’s specification ratings, (they all have them: weight limit, shear limit, torque limit, etc.).
2) Don’t ever over torque hardware past it’s rating.
3) Use the correct adhesives, and or locking hardware for the job. Red is not the same as blue, know the difference and their application limitations. 👍
Love your channel!
Your videos are Spot On!
The fasteners require replacement when torquing that hard because the surfaces experience very heavy sliding loads without lubricant and you get surface galling which seizes the fastener. For depth of thread beyond perhaps 2-3 turns of thread, the cross sectional area to loading is larger in the center part than the outer and the angle at which the loads are applied by the threads means you will snap the bolt and never rip the threads clean out.
It’s the same reason you can’t use an impact driver to remove heavily torqued bolts. If you remove them slowly, it’s fine. If you explode them off with a high power impact wrench the heavy load and fast speed friction weld the fastener in place and it seizes.
A good metallurgy lesson!!.
Your experiment is correct. But: Nuts and bolts are not designed to transfer torque. They are designed to pull, and nothing else. So what do you think, what works better in transferring a pulling force, a cured and then compressed polymer or steel? Spoiler alert: steel. Nuts and bolts are used to press surfaces together, for this task they need to be torqued down. Changing loads can cause bolts to rattle loose, and here is where adhesives come into play. They are not designed to increase any torque. Their single one and only use is to keep bolts from rattling loose. Nothing else. And by the way, torquing a nut or a bolt down is not intended to keep it tight. That's accomplished by thread geometry. The job of the applied torque is to generate the designed pressing force on the working surface of the workpiece.
This exactly. Preload and clamping force are the only engineered parameters, torque spec is just a translation of those parameters into an assembly step that's going to produce repeatable results without complicated QA steps.
Give that man a cigar!
Lmao, you realize that there are MANY other applications for threads than applying clamping force?
Just as there are MANY applications for Loctite where it is holding the threads in the desired position with no assistance from anything else.
So, you are basically entirely wrong.
@ke6gwf obviously, you have no basic understanding of the different types of threads and their applications. In the video it's solely about standard bolt threads, which are designed for clamping force only. I'm a certified technical engineer in Germany, my studies included threads, securing threads, thread locking adhesives, thread applications, tightening torques etc. What are your sources?
@@andrebartels1690 I'm wondering if he has a point, although not well stated, in that threads can be used for adjustment mechanisms, simply to move one assembly relative to another, where the threads are essentially a lever, there is no clamping force involved, and friction is usually an adequate mechanism for keeping the assembly stable in use. Extremely common of course. Perhaps there are other categories.
I saw my grandpa torque a nut down then take a flathead screwdriver and hammer to bend the thread on the bolt once. It worked on his box scrape (it gets lots of vibration). That was back in the 70's and he didn't have a second nut to lock with.
That's basically what mechanical staking is. You deform the metal with a punch or chisel so that it physically can't unscrew without bending or breaking the deformed metal
I’ve done that myself. Just rap the threads a tap with a hammer when. Didn’t have a lock nut
Thanks for publishing your science for the benefit of all, too much information is behind paywalls these days. Cheers
You’re welcome and thank you for the feedback!
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Great test, could you test reused bolts … bolts with old locktite, old loctite with new added, improperly cleaned bolts with new loctite.
Surface prep is critical. When you're using stainless or plated metals (less reactive metals) thread lock primer can make a difference. They also have special thread lockers for less reactive metals. If you get it right, breaking a bolt loose that has the permanent thread locker on it is really difficult and can damage the bolts. Just last weekend I had to disassemble some stainless parts with the permanent thread locker and we needed to use heat to get some of them to budge at all. Which brings up, if you need to disassemble some properly thread locked parts, heat will make the thread locker release significantly reducing how much torque is required.
Heat.
Brings to mind the adage "... suitable application of high explosives..." ☆
@@fjb4932 SS is a whole different animal. We use anti seize on SS always.
Three weeks ago we had a Loctite rep at work. The rep said it has to be reactive metal. Zink is non reactive. The test is completely invalid.
@@NathanailStiversit's not, because if you refer to the actual Loctite technical documents you will find that while Activator is Recommended for zinc plated, but mainly to speed up the curing time, but it will still cure on them, it just takes longer.
Also, that style zinc coating is so thin that it should still get some contact with the steel underneath, especially on cut threads.
I've used threadlocker to secure dovetailed metal joints into place, no torque involved whatsoever. Had a pistol front sight that became loose and liked to slide back and forth making it completely unreliable, but Loctite froze it right in place. Also if you ever want to change the forend on a Henry lever action, the ring holding the magazine tube under the barrel is attached via dovetail joint that must be punched out. If you do this it will inevitably loosen up, and once again Loctite is your friend.
You don't get much extra brakeloose torque if you use "loctite and torque" because if you have enough force to break the loctite then you've already far surpassed the requirement for the nut on torque alone.
This would be my theory as well. The Loctite and bolt preload are two different mechanisms being acted upon by the same breakaway torque. It would stand to reason that they'd both fail once the higher breakaway value is reached.
preload exists not to increase breakaway torque, but to reduce fatigue in the bolts.
loctite exists to increase the amount of time a torqued joint stays torqued after experiencing vibration and live loads.
Clamping force is also important in a lot of applications.
The preload provides an amount of clamping force required for the joint. Depending on what is being held together and why, that preload might be crucial to the function of the joint. For example brake discs on bicycles. What holds them in place is friction from the preload of the bolts. Without enough friction, the disc slides and bolts shear off under the type of load the assembly is otherwise rated for.
thread locker* exists to _
loctite has like 500 products. Epoxy and super glue being the most used ones.
This video, and the discussion below, is mind expanding. Thanks!
Thanks!
No… thank you! The support is much appreciated! 👍😎
Your hypothesis makes sense. I have found the same results with wood glue on wood. If I titen the wood together too much, all the glue squeezes out, and the joint fails to hold properly.
Here's what I was told in engineering school, and what I believe from decades of experience. Some of the other comments have alluded to some of this.
The loosening of bolts in service, in almost every application, is always caused by cyclical lateral movement. Either cyclical mechanical forces between the parts, or cyclical differential thermal expansion. Sometimes it happens at a near-microscopic scale. There's always nonzero clearance between the male and female threads, and each time there's any lateral movement of any kind there's also some tiny amount of rotation unless it's prevented somehow. Rinse and repeat, and eventually all preload is lost.
Split lockwashers do essentially nothing to counter this, and in many cases will allow a bolt to loosen faster than no washer at all. That's a whole other topic, too much to get into here, but they're a placebo in general. Internal or external toothed washers are much better, but still of limited utility. The Nord-Lock system is very effective, but only if applied properly. They can be done wrong by untrained personnel and then they're useless. I avoided using them, even when I could give detailed instructions in a manual, because it would only take one person ignoring or misunderstanding the manual and it would be worse than not having them in the first place.
The main function of a liquid locking compound is to fill in the clearance between the threads, so there can be no lateral movement that would start to loosen the threads. There is some adhesive action, but that's secondary. You're doing some good science and doing it well, but breakout torque is not really relevant. It doesn't simulate service conditions, I can't think of an application that creates an active torque trying to loosen a bolt. (That would be a VERY poor design!) Not to say this isn't good work, but it doesn't simulate actual service. Your vibration testing in other videos is much more relevant.
Locking nuts of various types are often a good answer. Nylon inserts (aircraft nuts colloquially) do a good job generally, giving an effect similar to locking compound. There are nuts on critical connections on my motorcycle, the axles for example, that have spring steel inserts that clamp down aggressively on the last thread. No matter what happens they will make it hard for the nut to vibrate loose, even if the preload is lost. I assume those are pretty expensive nuts.
Bottom line, in virtually every case, you're better off with Loctite or something similar than without. I have been using the orange Permatex orange for a few years personally and I like it. It claims to be as strong as red Loctite, but still removable with hand tools. I don't know about that, but I think it's better than blue Loctite. It has been working for me.
Whoa! I'll test Loctite threadlocker, but have some other things I want to test first. Thanks!
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I worked at a heavy equipment dealership years ago. A coworker was changing out a wheel loader cutting edge, he didn’t finish the job and went for coffee. When he come back he was unable to tighten up the mounting bolts with his impact gun. It was the dealerships practice to red loctite the nuts on, he left all of them loose. After seeing this video I now understand why those nuts were immovable! He had to torch off all the brand new fasteners and try again lol
Torching them off was a bit excessive - red (271) and green (270) loctite needs heating to about 250C to release it but you don't need to torch the fasteners in half.
As I'm sure many others have already pointed out, Loctite is not to make the but tighter, but just to help it hold and not back out in applications with vibration.
Yeah, basically it's the same as the nylon ring in a nylock nut.
Purely there to stop vibration loosening the nut.
What if I want my but tighter!🤣😂😅
@@pureblood6310stop using a bushing reamer on it😂
@@pureblood6310I was going to say it but you got it done before me😂
Well you're talking to type of groid here, so....
There is an optimum bond line thickness for adhesive joints. If it is too thin, you get lower strength. Many commercial adhesives contain spacer beads that are about 0.008" in diameter, so that when you assemble the joint you cannot press the adhesive too thin. I'm a big fan of threadlockers and keep half a dozen grades on hand for various applications. No doubt they have saved some expensive parts and possibly prevented me from having some crashes.
Best video. Super interesting, not 25-30 minutes long. Thanks!!!!
Makes sense.
Nice discovery.
Thanks! Much appreciated! 😎
A very nice job on the experiment and I agree with your reasoning. Just as blood cells are shaped with a concave surface on each side, surface area (or in this case contact area) is the key to the solution. More is less and less is more is the way of most things.
Another thing to keep in mind is that bolts stretch as the torque is applied.
Try a more realistic loading scenario for the bolts. Try adding some material to be under the clamping forces of the bolt and nut, and with/without loctite.
Interesting. Good insight on the analysis. On a separate note: stainless steel requires a primer to cure. Rep from Henkel shared a story from a dairy farm that had concerns with Loctite and stainless steel.
Thanks! I'm thinking of testing stainless steel nuts and bolts with and without an activator/primer. 😎
@@HacksbyDad Be sure to read up on the issues with galling and stainless fasteners. This is why *lubricants* are often recommend on stainless fasteners.
I can verify, properly used primer definitely helps. Just last weekend I was disassembling and re-assembling stainless parts and we were using primer. We applied the primer, let it dry 5 minutes (according to directions), I coated all the bolts with thread locker and spun them finger tight and left it as I did some other assembly work. When I got back to the finger tight bolts, they were already starting to bind up from the thread locker curing due to the primer.
They guy at the store told me Loctite is activated with absence of O2 -- he said a guy combined two semi-full bottles into one, and with the bottle being full, the whole bottle turned into a rock. Just passing along.
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I remember reading something about how when you touch the tip of the bottle to the metal, it can set off that reaction (not a chemist here so I can't explain the deets) to eventually solidify the bottle. Possible one of the bottles was "contaminated"? I know I've had to toss out old bottles that solidified.
My dad did that about 40 years ago.
i bought a bottle of cyanoacrylate and used a little then put the cap on, it turned into a rock in weeks to months. the only way to save cyanoacrylate it is to discard the cap and put hot glue over the hole, polypropylene will not work to seal it.
@@martin-vv9lfstore opened CA glue in the freezer, it lasts a long time.
Thank you for sharing your update. Everyone stay safe, happy and healthy. From Henrico County Virginia
You're welcome! 😎
Hey man, just so you know. A bit heavy handed on the loctite, had a training seminar at work by loctite as I'm a truck mechanic. Turns out too much loctite will more likely break free compared to the correct amount. Around half a drop on an m8 thread is plenty.
I’ve used nail polish in a pinch and it works.
Great experiment. Thank you.
So basicly Crossthreading a nut and bolt + threadlocker is worlds strongest joint still
Cant beat that good ole alabama loctite. (Crossthread and full send) 😂
Old boy taught me years ago that "Crossthread" is better than 3 lock washers 🤣 🤣
Don't forget rusting!
Here’sa good one: big,big punch presses have 4 huge bolts to retain them top to bottom. They heat these long bolts up really hot, spin the nuts tight. And let it cool. Talk about tight!
That is a good one! I wonder if I can do a small scale experiment. Maybe heat a bolt, insert it into a jig, finger tight a nut, let it cool, and then see how much torque it takes to break loose the nut. I’ll add this to my list and think about it more. Thanks!
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@@HacksbyDad I don't get it, wouldn't the bolts being heated expand, then when you finger tight a nut, it'd get loose when the bolt cools and shrinks?
@@SantiagoArraga I think the point is that the length of the heated bolts would shrink, thus tightening the joint which would, I assume, increase the torque required for loosening.
This is how old-school hot riveting works. Heat the rivet to cherry red, insert in part, mushroom the second end, and when they cool they shrink lengthwise and generate tremendous clamping force.
This is so cool! I knew this from experience, but presented like this with numbers and as a progression of ideas and tests? ❤️ 😂 Thank you!
Isn't the point of loctite to keep the nut from backing out from extended and repeated vibration? Doesn't matter if it's torqued down or not.
Bolts, nuts and thread systems are there to apply a clamping force to an object. Like the tread in an engine block and the head bolt apply a force that sandwiches the head, head gasket and surface of block. We try and achieve the correct clamping force by applying a known torque to the fastners which should achieve that clamping force, other ways that can be used to set a reliable clamping force are to measure the elongation of the bolt as it is stretched by the clamping force.
With just the nut and bolt solution without any extra locking mechanism the system is reliant on the friction within the threads and the contact surface of the nut and bolt on the clamped object to prevent it from undoing itself. Differential temperature expansion, vibration or impacts place momentary large forces on the fastner system that can overcome that friction and start undoing the nut. Without any other mechanism the clamping force applied rapidly decreases and the fastner loosens quickly. Spring washers better absorbs the momentary forces without the fastener loosening.
Liquid threadlock applies no friction within the threads when doing up the fastner allowing a correct torque to be applied for the clamping force required, and then hardens inside the threads greatly increasing the friction within the threads increasing the torque required for the nut and bolt threads to move, while not significantly changing the clamping force.
My guess is that you will see much stronger results with blue, or maybe green loctite. Red loctite is made for high bond gaps, while green is for very small bond gaps. Blue is in the middle. You are likely squeezing the bond surfaces so tight that the red loctite can't actually form under the correct gap conditions. This is something I have run into with metal/carbon fiber bond surfaces, you can greatly improve the bond strength by blending the epoxy with glass beads with diameter equal to the exact bond gap the epoxy is made for.
I found a comment that stated, “ if the metals corrode no primer is needed, if they don’t corrode (ie. coating) a primer is needed!
I would assume the strongest bond would be it. So 1 or 2 = 2. If you went higher torque beyond what threadlock can offer, it probably would be that. Treating threadlock as glue .
Awesome Video, easy to follow and logically performed. I can’t find any fault with the test you performed nor with the conclusion you came to. When I heard that people were complaining that you HAD to torque a bolt for Loctite to work I Immediately was like “What you(those ppl) smoking foo!”
Most everyone should know it cures in an anaerobic environment which is why they sell the bottles only half full … cuz it needs the air in the bottle to prevent the fluid from kicking off in the bottle.
I had never heard anything about needing to torque to achieve a suitable environment for that to occur, most anyone who has used more than 1 tube has almost certainly had a situation where they needed to temporarily hold the position of a nut or bolt in place and used a dab of Loctite to achieve it, had mechanical torque been required to achieve that environment it would never have begun to set up.
Logically if you just think about it, even a relatively small amount of water or oil are capable of filling the gaps between mating threads of fasteners thus displacing the air while doing so … with the only oxygen present being on the small openings on the two ends of the threaded spiral the Loctite in the middle farthest from those opening begins to meet the criteria for driving the reaction. I would venture to guess that there is a threshold involving volume to surface area contact with oxygen that needs to be met to kick off the reaction which probably then keeps getting driven forward.
I think it is only preload that keeps a fastener from coming loose. If preload goes low during a vibration or force change, the fastener has a change to come loose. Loctite and other methods (spring washer, nord lock, nyloc nuts etc) only prevent the fastener from falling out after the fastener has come loose. Proper torqued fasteners in a stiff construction don’t come loose.
It’s important to note the type of failure your adhesive is under (ie. cohesive/adhesive). Assuming your loctite isn’t expired, you’re likely facing adhesion failure to substrate, and this is always due to poor mechanical adhesion as a result of contaminates.
Always always always clean your threads and wipe dry with solvent before applying adhesives.
I had an OLD dump truck and one of the air controls for the tarp (Aluminum arm threaded in steel stripped out) Red loctite and stuffed it in the hole like gluing a plastic model together. Still works to this day with the 3rd owner of the truck. In my situation it was a quick fix that worked like metal glue. Big gap and not squish out. Nice vid!
One of the main uses of locktite is to keep a fastener tight when it is subject to vibration. Time for another test!
Because Torque does not add, once you “break” the first barrier, the second one is the only thing that keeps holding on to it. It’s a spring, slipping at a certain level, not two springs supporting each other.
Use loctite 242 instead of 271. 242 makes a gummy whitish substance to help with vibration loosening. 271 needs heat to loosen after a long time being used
Great testing methodology! If you're going do to additional tests in the future, it would be interesting to see how Locktite 290 (wicking-grade threadlocker) works in practice with similar testing. I think that can be applied by first torquing the nut dry and then applying the wicking treadlocker. I would be seriously disappointed if it didn't clearly increase breaking torque required after curing.
I got you covered. Here's a video with green Loctite... th-cam.com/video/amqesHpyCKg/w-d-xo.html
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Interesting find, makes sense now!
All depends which one you use. There are many different red thread lockers. Some don't really dry at all. Or dry but are easy to remove. Others dry very hard. Each is use for a certain situation. Depends on the type of bolt. What the bolt is made of. With the bolt be on a exhaust or engine. Where it faces high heat. And heating and cooling. Or is it in a standard temperature location. What other elements will it face. Cold,wet, salty,( road salt) or rusty location. Torq is not required at all. I use it to lock a set screw. At a set depth. And it with stands daily heating and cooling on a special exhaust application.
So next question since you've figured this part out... Does Loctite 271 work best with any particular metal coating/plating???🤔 The two other platings/coatings I am specifically thinking of are "Yellow Chromate" and "Black Oxide"!!!
Not sure. It might be worth testing. Thanks!
Great job!! Very interesting
Don’t forget to account for Class of threads Class 1, 2, 3 (A&B) this will effect squeeze out significantly, as the closer tolerance Class 3 will have less room for thread locker
Also would like to see your test for VC3 and other acrylic compounds! 😊
in Poland we say: klej trzyma gdy go ni ma, which translates to: the glue holds when it is not in there. Meaning, glue works best when it is squeezed out almost entirely from between the surfaces. It’s funny to see this test, which shows that Loctite is not glue, meaning it behaves in a counterintuitive way
Interesting info, thanks !!!
I'd be interested in the results with different thread tolerances. Most nuts and bolts are a 2H fit. By the time you get up to a 6H fit, there is no place for the thread locker to occupy.
Also maybe a test on Acme and Buttress threads?
Loctite is not adhesive in the traditional sense. It is essentially a gum that fills the thread pathway and increases shear friction as the threads rub past each other. Just like a nut with nylon insert.
In this way you can see why a loose nut having two bearing surfaces (both sides of the thread V shape) with a friction increasing addative requires more torque than one side of the thread V plus metal on metal contact for the tight nut.
One has to remember that the question of how threadlocker is chiefly intended to be employed is a different question than asking whether it will or won't function in some particular application.
"Loctite isn't _supposed_ to be used that way!" Maybe. But if what it will actually do under those circumstances is what you want, well, the Threadlockee Police aren't gonna kick down your door.
What about new bolts from factory that come with dry threadlocker pre-applied?
Try Loctite 648. It’s a retaining compound but it will do a better job for tight clearances.
Good info!
While loctire's PURPOSE is not to "increase" torque required to remove a fastener, in most instances (especially the red stuff) it actually does! Anyone working on a device on which someone had installed relatively small fasteners using loctite red, immediately is aware that removal torque has been greatly impacted. Its bond is such that, unless heated, its not uncommon to snap the heads off fasteners, or "pull out the threads" from aluminum and other soft alloy materials.
The greatest impact that loctite makes to removal torque is from its adhesive bond with the fastener...that's why the "loctite + torque scenario actually provides for lower removal torque than loctite alone...in effect, with increasing torque the fastener squeezes more of the loctite from between the applied surfaces resulting in less bond strength. In effect, the "thickness" of the loctite between the fastener threads is reduced, which in turn reduces the strength of the physical adhesive bond. So.. to summarize: loctite's ability to increase removal torque is just a "by-product" of its curing process. In reality, it is simply a "chemically resistant" adhesive, that by filling in voids between threads (and also providing some degree of a "gluing action") results in a fastener joint that is less likely to loosen due to vibration or heat/cold cycles. In some applications. (Semi-truck lug nuts for example) the fastener is massively torqued when installed...and loctites ability to increase removal torque is such that it only adds a tiny increase to the lug's overall removal torque value (if someone actually used it in such an application).
Of separate note: most all loctite formulas require some degree of copper in the surfaces being bonded in order to cure properly. This why loctite (or equivalent) "primer" is necessary when dealing with stainless steel and certain other potential fastener materials and plating treatments. Without it generally "remains wet" and doesn't set up to perform a bond.
According to Henkel, Loctite is not an adhesive. Yes, there is some 'adhesiveness', but it works by taking up the space in the thread. This is why you are supposed to be generous with its use. The initial breaking loose is probably the initial crushing of the solidified Loctite. This also why torqued and untorqued joints have the same break loose torque. Also, Loctite acts as a lubricant. This means if you torque to the same amount as a dry joint, you are getting higher preload in the joint. This will be throwing your test off a bit.
I found it fascinating, that when working on newer vehicles, sometimes replacement of a component requires new hardware replacement. Usually the nuts/bolts are simply ordered as a kit.
Sometimes the composition of the bolts, maybe are made of magnesium, aluminum, etc (some material that now makes it torque to yield, or stretch bolts).
When you get this new bag of hardware, i found it fascinating that the manufacturer preapplies loctite to the threads of these new bolts/nuts.
Purpose of this post, is to dig into applying any version of loctite, BUT, ALLOWING THE PRODUCT TO FULLY DRY FIRST (probably a 24hr downtime), THEN ASSEMBLE. I would love to hear some feedback regarding this.
Manufacturers don't like to apply liquids and glues on the assy line. Of course, if they're using threaded inserts with a locking feature, the replacement bolts don't do much better than the original one.
@@tubergonz for example, bmw. I remember their parts department had a display on their parts department counter. It demonstrated the weight savings of opting to use magnesium bolts and fasteners, over the traditional steel. The weight difference was obvious. Don't really think it's fair to say, that's why they started applying thread locker, due to the tensile strength just isn't enough to simply torque the magnesium or steel bolt to the same value. The magnesium stuff probably has a lower torque spec, which necessitates the need for the thread lock application.
@@sidewayzmike I'm going to have to look further into magnesium fasteners. It's kinda funny but aircraft seats don't use them much at all. I guess its cost.
How about trying loctite primer first using the same test method?
Any comments on using Nyloc nuts in conjunction with Loctite? Seems like that would just be an extra layer of security.
🟥 did the bolts and nuts have any protective coating from the manufacturer? If so, was it removed?
Zinc.
Actually cleaning them before the test would have improved the experiment... cutting oil residue from manufacturing might still be there
@@aldoloveri3493 Mass-produced bolts aren't cut. To make threads they're rolled between grooved plates while still red hot, then zinc plated.
@@aldoloveri3493 I agree
Try that all again but Use brake cleaner or a similar cleaning solvent to clean the threads first.
WOW 😮 nice work! Good science
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Благодаря! Thank you!
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Different purpose mate. Torque is to hold the part and protect the bolt / stud and nut. Thread lock is to prevent it coming undone.
Locktite plus lock washer plus nylon lock nut. Then spot weld....
Then peen over the thread end for a truly Professional job that will last long enough for the cheque to clear.
Nice! At first, I considered this to be pure geekery, but no; this stuff matters.
Perhaps the problem is that Loctite has some flexibility to it so even the torqued nut you start to break it free before the threadlocker holds it back.
I learned something, thanks
Clean the nut and bolt in acetone before adding loctite. I have NEVER been able to remove a bolt that has red loctite without heat from a propane torch. And I didn't use zinc plated bolt or nut either.
Thread locking compounds are fine when you do not want stuff to fall apart.
They are an absolute Cnut when someone (like me) tries to work on your car, and it is literally glued together and won’t come apart. Ever.
I had to replace the engine torque bar (bottom middle engine mount) on a 2016 Ford S-max, the rubber bit had failed. . . .
I had to remove the subframe from the car, and use induction heating to heat up the threads in the subframe to melt the excessive amount of thread-lock.
The bolt was going to snap.
20 seconds of heat, and it came out with no effort.
Then I had to re-tap the subframe to remove the thread lock.
It was not a case of ‘we do not want it to fall apart’ as a case of ‘we do not want it to ever be taken apart, buy a new car.”
Ho braddah, yeah i think youre right about loctite filling the gaps. Its more like a nylock. Rust also works. Anything to fill the gap in the threads. Check out nordlock washers if you wanna get fasteners locked up. Nothing like them. You'll think ever bolts gonna snap during disassembly. Dig in to bolts stretch and yield %. When you factor stretch, the long the fastener, the more turns it takes till the tension is removed, you may find loctite to be more effective, as its crystals bind in the threads more. Try bolt with a long spacer tube, like 3" long bolts, so you need like 1/2 a turn or more before the tension is removed. Fastening can be a deep dive into materials science.
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Cool test. Now try it with the primer. Loctite doesn't love zinc plated hardware.
Interesting! Now visit the possibility that the lesser force required to loosen the torqued samples are not due to squeeze out of the threadlocker but rather due to mechanical forces already pushing the nut/fastener towards the loose side. When you press something on a surface there's an opposing force generated which would aid the loosening of a hypothetical nut on a thread. Just a theory.
P.S. I don't see how you'd squeeze out threadlocker from threads that are not compressing while you torque the nut. Even so, the same amount of threadlocker would remain in the next set of threads and, ultimately, squeezed out paste would be visible at the edges (which every time I apply threadlocker, it's definitely not there). Maybe if you put more we'd be able to see it.
Did you ever try allowing the loctite to dry on the threads before running your nut down the thread and torquing to setting?
Maybe try different dry times too 🤔🤷🏻♂️
Thanks! Loctite threadlocker cures in the absence of air, so I would need to figure a way to remove the air. Maybe wrap in plastic wrap?
Here's a video on different cure times... th-cam.com/video/Xmkc4mDVw3w/w-d-xo.html
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Thread Locker is not about torque. It's about keeping the fastener from loosening.
Similar to what nylon lock nuts or lock washers do. But more reliable.
Cross thread works every time
I thought red says needs heat to remove.
Does it matter in real life how much prevailing or breakaway torque locktite provides when the nut hasn't been torqued? Who uses it in that matter? Maybe something that is shipped while loosely assembled and the final torque is applied later? I've seen loosely assembled fasteners come apart due to sympathetic vibrations during shipping.
Thanks. I don’t think it matters much. In my opinion, Testing loose or untorqued nuts removes a variable and simplifies the testing process. It also gives higher results that look more impressive. 😎
there are applications with sliding or rotating mechanisms where a nut is not intended to be torqued.
when you torque the nut, it squeezes out the Loctite, so you have less glue between the threads. anyway you need to torque it to the correct specs to begin with
Have been using a drop of rtv as thread lock for years
Removing a small amount of the thread peaks on both the bolts and nuts.
This should afford more space for thread locker.
Bolt ( seized ? ) by ANY Loctite™ ... heat it up ( you MAY have to use a blowlamp ! ) ... instant release😝 ! and this works for all other companies , liquid " thread lockers " ..( tried - n - tested ) .... DAVE™🛑
When you add two chains in a row it doesn't double the strength.
Excellent video and excellent detective work! Your results seem compelling. However I'm struggling to understand why "squeeze out" reduces the strength of Loctite so dramatically. One would think that when the metal faces are pressed together, there would still be a very thin layer of glue remaining. Why doesn't that thin layer provide bonding strength?? I believe many other adhesives bond just fine when cured under pressure. Why not Loctite?
Thanks!
Squeeze out by applying too much clamping pressure also affects wood glues. Maybe I should add that to my list of video ideas. 👍😎
Best Anaerobic curing : Reactive metals like iron, steel, copper, or brass are ideal, basically a catalyst. Narrow bond gaps, clean surfaces, temp 68f to 86f, oxygen or lack there of. Non optimium is opposite of this.
Zinc is more reactive than iron/steel, which is why it's a coating or sacrificial anode, to oxidize before the iron can.
I've seen several comments and the video itself state that a lack of oxygen is required for an anaerobic thread locking compound to cure. I believe that is incorrect. The "anaerobic" bit doesn't mean the reaction needs a LACK of oxygen. It only means the reaction doesn't NEED oxygen.
For reference, 11 foot pounds is very low.
With grade 8 bolts, just a 1/4-20 gets 14 foot pounds, and that's barely enough to flex your wrist.
Have you tried this with Loctite primer?
Thanks! I tested Loctite primer, but not with this particular test. Here's the other test... th-cam.com/video/iz9qhPx0Hr0/w-d-xo.html
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Not a huge fan of the stuff.
I use 3m yellow weatherstrip adhesive and it has about the same strength as blue 241, and won't cause issues where ive seen it corrode fasteners.
Of course the red is needed for the strength ,but most applications the 3m works great.
Thread locking compounds will not work properly with out its Cleaner/primer that is required with it. Loctite 7649 is needed to make it work properly.
Thanks! The primer has its place… Loctite PRIMER?! Most DIYers Have No Idea
th-cam.com/video/iz9qhPx0Hr0/w-d-xo.html
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As soon as I saw the specs im the beginning my theory was surface area is bigger on a loose nut. I cannot however see how the formula is relevant in any way
Required loosening torque = max(A,B)
simple, enough force to break the TL already surpassed the break of the torque
once the TL broke, that force was still applied, so it broke the torque
At the end of the video, I think you have the graphics and the text combination reversed. 65% should be shown in combination with the tightened threads.
Hammer some flats onto the bolt thread then run the nuts onto the flats.
JB weld the rest and test that.
Weld the end of the bolt or stud to retain anything that could fall off.
Welding will work. Stop playing with bs in tubes. Mig weld.
You could also wrap wire around the treads to retain the nuts..
My theory was that the harder metal on metal surfaces vibrate more thus it gets loose faster.
I thought the loctite acted as a lubricant - negating the torquing affect.
I thought so too. Here's a test I did... th-cam.com/video/SLBx09En_P0/w-d-xo.html
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@HacksbyDad Good test, and the Nord-Lock video and chart confirming your results is a nice touch! Surprising that wet locktite has more friction than steel on steel. Perhaps there is an additive with this in mind.
Thanks!
Thread locker is not a glue. It fills gaps between threads therefore prevents cross axial movement nut to bolt under dynamic load. Gluing is a side effect😊
Thanks! Threadlocker by definition is an anaerobic "adhesive." In addition to filling the gaps, it also adheres to and grabs the surfaces to minimize movement. The breakaway torque is a simple way to measure the adhesive strength of the threadlocker. I'm working on a new vibration test to put various threadlockers, lock washers, and lock nuts through their paces.
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@@HacksbyDad NAS vibration test? Have made some. You'll be surprised too
@@andreystepanov8643 Yup! You read my mind! A DIY NAS vibration test. The Junker test doesn't seem as realistic. Here's my first version of the DIY NAS test... th-cam.com/video/lwtUWB2TIYA/w-d-xo.html
th-cam.com/video/4H-HOHZ3chA/w-d-xo.html
The rig is too cumbersome. My next rig will be more light-weight.
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@@HacksbyDad You have done it already)
Junker test shows different results. Each connection requires its own fixing solution
@@andreystepanov8643 👍😎