Lmao got a physics professor to Ghost you after making an interesting observation! That's why I love this channel, and also the straight forward approach to letting people know what tools actually do, vs their advertised specs! Thank you for your Content!

Something I noticed from your graphs: The super heavy lead socket seemed to not hit its peak in your short duration tests. It started out slow, which makes sense. It's a lot of mass to get spinning. But it also never hit that plateau that you see from all the other sockets. It's slow to get spinning, but that also means that once it is spinning, it's also carrying more momentum and slower to STOP spinning as well. I'm curious what it would do in a longer test.

What matters is moment of inertia, which is mass x radius squared. This is why your hollow socket performed well - it probably had the same moment of inertia of some of the far 'less heavy' solid versions you tried. The mass at the larger radius has a very big effect on moment of inertia, where the mass you saver by making it hollow has a relatively small effect. It's also why the IR one performed less well with it's flywheel cut off. You probably didn't reduce it's mass by much (30%?), but enormously reduced it's moment of inertia. You only have a limited amount of energy from each impact from the wrench to accelerate the socket. This is why 'heavier' (i.e.a higher moment of inertia) isn't always better. Imagine a socket with an insanely high moment of inertia. The impacts from the wrench will be so small relative t o it that it'll not move at all. This is why the whole front wheel doesn't turn when trying to undo a stuck wheel nut with an impact wrench - the energy from each wrench impact is almost totally insignificant because the moment of inertia of the whole wheel is enormously high relative to what the wrench is designed to turn. There will be an optimum moment of inertia of the socket for each impact wrench running at a particular pressure, where the energy it has from each impact to accelerate the socket is transferred most efficiently to the socket (and then 'dumped' into the nut or bolt. The highest readings you for will be where the moment of inertia of your socket most closely matched this optimum value for that wrench and air pressure (mechanical impedance matching).

06:23 - The welds along the washers will be flexing, reducing torque transmission and losing energy to heat in the flexing motion. The other designs use a single body which massively reduces flexing. The flywheel one may be using resonance to store energy and release it in between hammer blows. It may perform differently on different impact wrenches, providing little gain on one but more gain on another. Total guess.

From the results it would seem like that the more outwards the mass is, the better it is. So maybe you could try to weld together a souped up flywheel design and give it a go? Also, perhaps a good way to test the effects of rigidity vs. outboard mass would be to use pipes of same weight but differing sizes and wall diameters.

Mechanical engineer here, the goal of these attachments is to achieve better dynamic frequency responses out of the tool. The resonant frequencies are difficult to pinpoint and just about every condition influences if you can perform at a resonant frequency. If your attachment makes the tool perform at a natural, resonant frequency, you will see force multiplication on the output. I think there’s a MythBusters episode about this.

I think the flywheel acts as a resonating element (constructive interference). If so, then it only works well on some tools where the forces, masses and spring constants are in harmony.

This channel is informative, uses clear communication, and delivers it with a humorous, entertaining voice-over. Well done!

Every time I watch a video on this channel, I have the same thought: between your obvious intellect, the creative and entertaining ways in which you test various products and theories, and the ease with which you articulate the results, Astro hit a grand slam when they hired you. I sincerely hope they realize that.

Have you considered making a "flywheel extension" (a short anvil extention with a flywheel welded on it) so the weighted flywheel could be added and removed using any socket? Would be a handy tool to have if it worked the same

My gut instinct says it is the difference between regular inertia, like when you throw something, versus rotational inertia, like when you spin something, since an equally weighted socket with more mass at the outside would have more rotational inertia. Regardless of how anyone feels about the matter, there are absolutely some things that you can do to test the theory and narrow down what is causing the particular behavior of the IR Powersocket. What you could do is make 3 more home made sockets as a test. 1: a homemade powersocket, which is a regular socket with a ring at the base. 2: welding a ring at the bolt end instead of the drive end. 3: a powersocket with a much larger ring. Having a much larger diameter ring would absolutely confirm or deny the rotational inertia theory. Testing with a ring at the front versua the back will test if the effect is stiffness related. Perhaps the most power loss in a socket is at the interface between the impact drive adapter and the square hole of the socket and having extra mass/inertia at the base of the socket helps counteract that?

The way to solve this (I think...), is to make a hollow socket with different diameters but same weights (or at least very close). I wonder if at some point there would be diminishing returns as you go wider, or maybe not if you can keep the same weight somehow.

A couple of thoughts: -Firstly I think it’s most useful to think about this problem in terms of angular inertia. E.g a weight put further out contributes more to inertia to the socket than the same weight close to the center line. - In those terms it looks possible that all of the sockets that perform well kind of cluster in the same region. Either having little weight far away from the body like the hollow socket or a fair bit of weight concentrated close the the center like the Lyle. -This suggests that there’s an optimum amount of angular inertia for a socket to have -If this is the case then we can explain the lead and heavy washer sockets low performance by them being further from this optimum amount. -But then why does this optimum exist? -I can only hazard a guess but we already know that increasing the hammer mass of an impact improves its performance. -But we’re not increasing the mass of the hammer you say. True but the socket is the hammer from the perspective of the bolt. -That would explain why increasing the weight of the socket improves performance. But we also need to explain why there’s an upper limit where performance drops off. - If we again think of the socket-anvil-hammer system as the hammer from the bolts perspective perhaps the super heavy socket prevents the system from reaching its maximum speed during the split second that it’s being accelerated by the impact before it in turn impacts the socket. This all suggests a couple more experiments. - Does relocating the weight of the socket to further from the centre also improve performance as my tiny knowledge of physics suggests? -Does my guess that it’s the weight of the entire socket anvil hammer system hold up. If we move an oz from the hammer to to socket what happens? -If we force the issue and remove all slop from the socket anvil joint by say welding the socket on does the impact perform the same? Awesome video as always

I would love to see you test a homebrew socket with and even wider flywheel design. A ridiculously wide, yet similar mass experiment to see if equal or even less mass at a further distance from center increases the moment of inertia.

Spring tension might be a factor. Metal used in bolts and tool steel isn't 100% rigid, if it was, it would sheer off or fracture under torsional load. The flywheel design might be using that spring tension to keep the socket from "flexing" as much when the impact hammer releases it's energy into the socket.The metal wants to spin the opposite way that you twisted it because of spring tension in the metal. Theoretically, you could reduce that from happening with a flywheel.

Love the curiosity here and the determination to confirm things and not just accept manufacturer’s claims! Love the experiment with molten lead socket and “modifying” the IR socket!

I have every Lisle socket they sell and use them many places were you can fit them on chassis and suspension bolts when you need them they are cheap and work great

In a way the heavier sockets help facilitate a form mechanical impedance matching, similar to how a horn amplifies sound. Mark Rober had an excellent demonstration of mechanical impedance matching in his video on the worlds largest horn where he demonstrates the effect on a block of jello. Also the drum might be more efficient due to the moment on inertia for a ring/tube being greater than a disk/cylinder, allowing for a more efficient use of a given mass. You could test it by having to sockets of the same weight but make one hollow.

I had to get a weighted 17mm for my honda crankshaft. It wouldn't budge with a normal impact socket but as soon as I put the weighted socket on it and gave it the beans, came right off. Super useful socket.

Excellent video presentation, you were able to lead us to the conclusion without spelling it out and confirming what your findings suggested with a reputable source. It’s interesting that these impacts are so powerful that you are actually losing power from the sockets flexing as this video shows, and also might explain why the effect could be lesser with larger sockets, because they are larger and more rigid and aren’t being delivered the same power per volume of steel, so there is less lost energy in vibration.

Very nice start. Gotta identify all the variables to the extent you can. Fitment to anvil, fitment to bolt, eccentricity of mass, internal rigidity, thermal properties during stress; those occur to me but there are surely more.

Maybe some sort harmonic thing happening? Everything is a spring after all. Those webs in the IR socket may be flexing under impact and the rebound is imparting more energy into the blow.

The answer comes not from a static analysis like the Physics prof did, but by a harmonic analysis of the tool. It is the flexible/spring characteristics combining with the outer mass that do several things. In the first stage, the flywheel resists the blow, but stores the energy. In the second stage, the socket hits the bolt head and the flywheel returns the energy to increase the overall torque. In the next stage the flywheel actually stores some energy at the end of the impact. Next stage, that energy anti-rotates the socket between blows. This backwards rotation makes it easier during the next cycle to store energy in the flywheel because the socket gets a tiny bit of free turning before it hits the bolt and experiences resistance from that. Ultimately, the ideal design would have far away mass combined with a golden amount of flexibility connecting it to the socket.

Thanks for doing this - exploring why some things work and some don't 👍 The only sockets that conformed to what I thought were the lead socket and ultra heavy ones. Great channel !

Engineer here, my guess is that the free play between socket and nut is critical here - after each impact, the socket is bouncing back and getting a "run up" for the next impact. If so, the extra rotational inertia lets you build up more kinetic energy during this tiny run up window, much like a heavier hammer does inside drive. There could also be a natural frequency tubing element here, getting the socket to bounce back and forth in time with the impacts to help amplify. The high speed footage will hopefully show this. I'd like to see some tests between sockets that have very snug fits vs ones with some slip to see if this helps or hinders.

It would be interesting to see the weighted sockets on the high speed camera. The heavy mass ones, might not show much. I would think the Ingersoll Rand Flywheel design and hollow design might show some interesting things. I would think the flywheel would whip helping the internal weights. I would also think the weight of the socket would be limited by the hammer mechanism of the impact. I’m just a HVACR Tech and ex Farmer, that’s my non engineer opinion. Really appreciate your channel and testing.

I appreciate how the questions you bring up are the exact questions that pop into my head while viewing your video. Those same questions are answered as best as possible a few seconds later or in a future video. Alot of diy's, professional, scientific, etc...youtubers, just gloss over or completely ignore obvious questions their results bring up. Amazing video. U da best.

Got home from work and was super happy to see a new video from you guys, especially since I've been waiting for a test like this and plan on buying the Lisle 19mm. Also, I just bought at 4am a Ridgid R86012 with charger and battery for $150 (black Friday deal) due to your amazing videos and still might have to pickup the R86211 HT used at some point. Thanks for all the amazing content!

It makes some sense to me. While it does take more energy to get a heavier socket moving, as long as you have that energy to get it moving it then has more momentum and will apply a higher torque before coming to a stop. Hence why the more powerful wrenches benefit more from the weighted sockets, and why going too heavy is detrimental when you don't have the energy to get it moving at a decent pace. I would imagine that the lead lined socket with something like a 1" impact behind it would perform even better. Things get complicated when you're dealing with impact forces and not continuous ones. Also the reason why the hollow socket performed well despite being light, like the IR socket it places that weight further from the axis of rotation which increases the torque and momentum that it was.

I bought the OEM 6 piece set of crank sockets. They work great, would like for you to test them they are only $99 set. My opinion it rigid because it’s thicker and won’t stretch or flex and adds a little weight which helps up to a point

These are not new (weighted sockets and bits), but your data collection and testing is! I don't wrench every day, but when I do it's helping with 5,000 lb dies with hex bolts with millions of injection cycles on them. Usually, just in an attempt to restore a moulding surface or to replace components. I find AirCats don't do it sometimes without significant heating (which is foul as all heck) so a torque assistive device such as these would likely help. As for the IR (I am not an enginerd but I play one at work) the toroid was attached with 3 spokes. The spokes could act as a delay or offset disconnecting the input torque from the output. Applying the spinning mass outward from the centre of applied rotation might be a torque "run up" with each impulse. The IR socket body just acts as a normal socket without the ring on spokes. I don't know. The hollow socket seems, to my mind, doing the same thing in a round about way. The mass is lower but applied further away from the axis of rotation. Man, this is all so much fun and interesting! (The stacked washers appear to be end welded with a few beads, so one would assume a lot of energy loss is happening there between the lack of connection of the washer's masses) l have to make one of these on Monday. Thanks TTC!

The reason the lead socket didn't work is because lead is a damper material and doesn't transfer impact force effectively. There has to be a balance of torsion and rebound speed along with mass. Those are the physics behind the IR socket, the bigger the diameter, the faster the rotational inertia resulting in more force with a smaller mass. Lisle uses the heavier mass at a smaller diameter approach. I have several variations of these sockets myself both retail and shop made and can confirm they do work. Great video as always 👍

Great video concept and execution! Don't be too fussed about the prof ghosting you, but it would be nice to get some other views from physicists on the matter.

I think the harmonics of the socket might be a really big influence, I'm wondering if the test results would be different with a different impact that has a different hammer mass and/or different BPM?

As the Ingersoll Rand PowerSocket is struck by the hammer tool, it is caused to oscillate at an ultrasonic/sonic frequency, which is briefly transferred to the bolt/nut, inducing a ultrasonic/sonic hammering effect at the interface of the thread/friction surface, thus overcoming the static resistance points. This effect is similar to the Ultrasonic/Sonic Jackhammer Researched, developed and produced by NASA (NPO-20856). An ultrasonic/sonic jackhammer (USJ) is the latest in a series of related devices, the first of which were reported in “Ultrasonic/Sonic Drill/Corers With Integrated Sensors” (NPO-20856), NASA Tech Briefs, Vol. 25, No. 1 (January 2003), page 38. Each of these devices cuts into a brittle material by means of hammering and chiselling actions of a tool bit excited with a combination of ultrasonic and sonic vibrations. A small-scale prototype of the USJ has been demonstrated. A fully developed, full-scale version of the USJ would be used for cutting through concrete, rocks, hard asphalt, and other materials to which conventional pneumatic jackhammers are applied, but the USJ would offer several advantages over conventional pneumatic jackhammers. Search for NASA (NPO-20856) for more information and white papers.

Like @allupro said in a previous comment, I believe the further out the weight acting on the pivot point (bolt head), acts as a lever applying torque in the forced direction. They all start out similar to the regular deep socket, but once directional momentum is achieved and the outward most mass is accelerated to the nominal force that the gun can apply, the weight (with its momentum) is applying more torque as a lever effect. The hollow socket reduces mass to achieve the momentum required for the torque, but also has the majority of its mass further from the fulcrum.

I would be curious to see how precise the fit of the socket on the anvil and the bolt would affect it, I feel like I have noticed a difference between different brands before I wonder if it's because one brand fits better

I'd love to see one of those hollow sockets filled with lead shot. I'd be curious to see if the dampening effect would hold the socket against the hex more consistently. Most of the power loss I've seen from impact sockets is from the socket bouncing backwards and the impact impulse being partially lost from the air gap created by that bouncing.

Mechanical engineer here. You don't tune a rotating object by just adding mass, you tune it by adding rotational inertia, which is a combination of mass and distance from the axis of rotation. Adding the same amount of mass, but further from the axis of rotation, adds more rotational inertia (while adding the same mass). Hollow fesign (and the flywheel design) maximise rotational onertia to mass ratio. It may also be a case of tuning for vibration effects, but someone already commented on that nicely.

I would really want to se a continuum of this tests since the lead socket did have a pretty steep slope at the end of the test so might overtake the other sockets in a 30s test or something

Wonder if the tightness of fit between the wrench and the socket (and extensions) as well as the socket to nut have just as big of an impact as the weight.

great video! love the science; keep up the great work guys!

Awesome video guys... I've always been curious about how much of an advantage weighted sockets offer. Interesting findings with the mass distribution too. Thank you very much!👍🏼 - DB Welding Services - England -

Perhaps the lead absorbed the energy? Maybe a hollow with a heavy flywheel made of strong stiff metal would be ideal?

Do you think a heavier battery transfers more rotational force to the fastener as well. We usually attribute all the gains of a larger battery to the added pixies. Would be interesting if you added weight to a Powerstack.

Super interesting topic. Thank you for sharing this with us. 🙏

Fantastic. 👍 Please keep up the great work. Very interesting 👌

There is a logical solution from physics standpoint. The stiffness of the socket increases the capability as it flexes less as you might think about torsion reducing sticks that only goes so far and start flexing. The mass might improve things but as for why the heavy spacer stack and lead version did not succeed is based on the fact that those have a low torsional rigidity. On the lead the lead is so soft that it flexes itself and the spacers were only strip welded which gives flex also. This is why the hollow large diameter pipe was a good one as the pipe is very rigid. The flywheel one shoud be very hard steel and delivers impact very well.

Awesome video. Thanks for sharing.

Strain-gauge analysis on an oscilloscope will show that a normal socket delivers a pronounced spike which is readily absorbed by the target material, whereas the modified socket delivers a continuum of stored energy which goes out of phase with the rebound of the target and thus results in a much higher total energy transfer over time. It's quite simple, really.

Great demonstration!

Haha, I can't say what is happening, but as soon as you summarized the prof, my immediate thought was "No, he's wrong, cut the flywheel off the IR and prove him wrong!" I was very gratified to see that almost immediately.

I broke 2 HF 1/2" impact extentions, removing Honda crank bolts. I have the Lysle weighted socket and then bought a new Earthquake impact gun. In the end, I built a long socket by cutting a deep impact socket in half and welding pipe in between. So it's one piece long enough to get past the fender, set on a jackstand, and use a breaker bar with my jack handle as a cheater. I bought 2 HF breaker bars, thinking one might fail. In the end, it worked. I later tested tightening a bolt with an estimated 500 ft/lbs (my 230lbs and a 30" cheater). My Earthquake could not remove it. So I bought the Hercules mid torque. It was just barely able to remove it. If I added a pipe wrench on the socket and leaned on it while using the gun, it was removed easily. My shop made pipe socket wasn't better at delivering torque except that I did not break like the extension. I may make an extension with a hex on it and try a large wrench combined with my impact. ps. Why are Honda bolts so tight?

One useful thing to test is how much the rigidity of the connection between the wrench and the socket affects the applied impact. I.e. if the socket is shrunk-fit onto the torque wrench, then they essentially act like one piece and you only have impact transfer from the socket into the bolt. But if the square drive is loose, then you have to transfer the impact from wrench to socket, and then from socket to bolt; so that means you have to impedance match the "moment of Inertia" twice, and you have two occasions to lose energy. The looser the connection - the more slack it has to take out before it acts like one piece. Now I reckon, that with a really tight socket (welded, shrink-fit), you wouldn't need any extra weights on the socket, and the extra weights should only hurt. (I'm using simplified phraseology here, obviously it's about dynamic moment of inertia and not weights)

The shot tword the end of the guy using the socket on a lug nut gave me an idea, try making a flywheel type mass out of a short 1 inch extension. I know there would be losses because reasons, but it would be usable on many different sockets. You could also play with weight diameters and see the difference.

good for you sharing this new information!

I love this channel seems to always touch home with me my son and I just got the Lile socket getting ready to remove damper on his daughters Honda hope it works

In collisions, the most energy is transferred from mass one to mass two when they are both of equal mass, maybe something similar is happening here- when the hammer/anvil is of equal moment of inertia to to the socket, energy is most efficiently transferred.? There's at least 4 bodies at play, so it might no be quite so elegant.

What an awesome video, I love investigations like this, so much fun!

Fantastic video as always! Interested to see where this goes. Maybe the flywheel added to rigidity somehow? (I'm only a high chair physicist at best)

Cool testing for sure!

God bless you for your merit. I loved all of this. Your questioning intrigue and plain spokeness without being high & mighty. Just seeking an answer. And your willingness to question those answers you received. In real world examples. This was a great video. I thank you so much for sharing.

Learning about tuned mass and such. High speed cameras and impact wrenches are a great combo.

Great testing! It’s super interesting. I’d recommend for you to get a lathe and make the diameter of the sockets you need 😇

In my 400 level FEA class in engineering one of the effects we looked at is the multiplication of force caused by the fact that forces applied to a part travel through the part and can reflect back(think pressure waves). So if you manage to set up a reflected wave properly it can multiply the final output force at least on occasion, and you end up landing some heavier blows even if it isn't on every blow from the impact. The lead socket was probably VERY good at dampening vibrations in itself, the best performing sockets probably ring the longest when struck (good luck holding the solid boy from lisle in a way that allows it to ring though) The design of the IR might be based on trying to get vibrations to reliably reflect around to and from the mass ring through the spokes.

This all makes perfect sense from the perspective of the physics. If the Prof ghosted you, he probably just got busy. This is all about efficiency... basically, you are trying to convert kinetic energy to force to do work. The TLDR version, the mix of extra rigidity, additional mass, and importantly, the additional mass that is placed far out from the point of rotation, all culminate to make the tool more efficient as it isn't losing energy bouncing around and can conserve its angular momentum better, but since the distance over which your socket is being accelerated is so short, too much mass will cost you too much momentum to be beneficial. The total amount of kinetic energy available is determined by the motor in the impact wrench. The job of the hammers and the gearing in the impact wrench is to convert that kinetic energy into force with which you can do work. There are a LOT of factors determining how efficient this process is, but we can break down what's going on here by looking at the equation for work, and conservation of angular momentum. W=F*D, and given that force=mass x acceleration, we can re-write that as W=M*A*D Conservation of angular momentum is a physical property of a spinning system such that its spin remains constant unless it is acted upon by an external torque. Angular momentum is determined by an object's mass, its velocity, and how far the mass extends out from the point of rotation. Lol.. ok I planned on explaining this in detail, but I am totally procrastinating my actual work in the process, so I'm going to cut this short. By having more mass farther out on the socket you reduce the amount of negative acceleration and loss of momentum the socket experiences when it impacts the bolt (the bolt is applying a negative torque to the socket). the net result is a smoother conversion of the kinetic energy to motion in the direction of the drive.. (think what happens when a mosquito hits a windshield.. you apply equal force to each other, but he feels a ridiculous amount of acceleration, and you feel practically none so your velocity and therefore your momentum is conserved). so ya.. more mass further out helps conserve angular momentum and reduces the degree of negative acceleration felt by the socket so less energy is wasted by the socket bouncing off the bolt with each impact. But remember, as with everything, there will be a sweet spot... KE=1/2*M*V^2, and P=M*V, so velocity is important, and if you have too much mass you won't be able to provide enough acceleration with a given amount of force to impart sufficient momentum over the tiny distances you have to work with in this situation. that's the condensed version.. hope it makes sense. cost you too much momentum to be beneficial. l mean

I had a similar theory about air hammer bits too; a heavier, denser tool will stay more deformed and almost spring loaded between hammer blows of the tool

Wow thats some serious work there!

Thanks. Very interesting and I could use that homemade one when I take off my leaf springs on my Jeep YJ soon. ;)

I tihnk it's the inertia on the outer ring of the flywheel socket that gives it the extra oomph. The weight is concentrated farther out, giving that mass a larger radius, which gives it more acceleration, which gives it more energy. It takes more energy to slow it down, so when the bolt tries to stop it the socket form turning, the extra flywheel energy is applied to the nut. I suspect what you can't see, is that it takes more energy to accelerate that socket because this socket and the regular socket both accelerate very quickly. It's like using a hammer on a fan clutch removal tool, the bigger the hammer, the more force applied. The longer the arm (so long as it does not twist and absorb the energy), the more force applied to the fan clutch hub. The hollow tube having more rigidity makes sense because more energy is transmitted to the nut and not a twisting twisting socket. Listle wins with rigidity, Ingersoll wins with extra energy. So the most ideal should be a hollow socket with a flywheel mounted on it where the anvil comes into the socket. You would need to draw a line and watch the socket with a high speed camera in order to see if the socket is actually twisting. If you put too much weight on a hollow socket, it will twist, the most weight you could add without it yielding would give the best results. Only other variable I could think of is too much weight could bog down the impact and absorb too much energy, but that's something you would have to test too. Great video! And the guy who made that hollow socket is freakin' smart!

Wow great video man. the best most Interesting content on the stuff 👍

Moving the mass farther out from the socket seemed to be the best method as the heavy condensed ones fell off compared to the hollow more weight outside and IR with flywheel.

As many others have stated, the mass isnt as important as the moment of intertia. My theory is that the moment of inertia needs to be tuned to the impact mechanism. You might gain some more info by attaching scales to your impact sockets and watching them in high speed video, plot the rotational position, velocity, acceleration etc. I wonder if permanantly attaching the socket to the anvil would help too. Last thing, if you want maximum mass tungstem is the material to use. You can buy tungsten wire on mcmaster, which you can then wrap around your outer tube. Then braze it in place. maximum mass concentrated far out. also a good way to increment the mass.

My stab at this is harmonics/resonance. The inners of that impact gun revolves with a certain speed under a certain load. The speed in combination with the weight of the anvil and rigidity of these parts will ideally translate into the impacts that is relayed from the gun to the nut without delay and energy loss. In most cases the natural frequency of the main components (determined by mass, stiffness, shape etc) mismatch, and there will be a lot of rattling around and wasting of oomph. In ideal cases their frequencies will match (could be first, second or third order and so on ) and the impacts will travel from the gun to the screw head in a cleaner way. There are also several unknown factors as play between the parts that could affect the result.

I feel the hollow socket is near a sweet spot in which the weight (and placement of said weight) allows the socket to reach optimal momentum (therefore delivering more kinetic energy) while simultaneously optimizing the centrifugal force applied to the socket and therefore the torque applied to the bolt. Here's a link to how to calculate it. (I posted this like 2 hours ago with the link but my comment keeps getting taken down? Maybe because of the link? You can find the calculator at omincalculator. Im sure you'll find it) I'll continue researching it more as well! Also, thank you for all your great content. Your clarity, humor, and rigor is more IMPACTFUL than you realize.

I've used the Lisle and was blown away at how well it worked on those stubborn F-series Honda crank bolts. I figured it was partly the increased mass, but also some increased rigidity allowing better torque transmission. Absolutely bitchin' that Astro's making a hollow socket, good work! Now find somebody to manufacture your gas-powered impact!

Thank you for this video - this has been puzzling to me up until I watched your video I believe that also harmonic vibration is at play here from the Impact Wrench . Henceforth some type of small harmonic balancer/damper or dampener may be the solution . The Rattler brand performance harmonic balancer is composed of internal rollers that absorb or displace resonance with variable rpm . Using an impact is WOT (wide open throttle) so a design with a rubber elastomer sandwiched in your hollow socket design may be on the right track .

As an engineer with a practical understanding of sockets/metal components I think there’s a good bit of resonance in the designs. If the impact shockwave starts at the drive end of the socket it can store energy into the flywheel, the bolt end of the socket starts to apply force, and at the same time the shockwave stored in the flywheel travels down the socket and hits the bolt at the right time to deliver more force. Too much weight and dampening, as is the case with the heavy, soft lead socket, would back this theory up, as would the high spring rate of the large hollow tube welded to the socket.

Tbh as a physicist it is fairly straightforward and I don't know why the professor was overthinking it. The heavy mass further from the center causes a higher moment at the time of impact. While each hammer blow doesn't move the socket much, it does move it. So the more mass it has further from the center the better. The heavy sockets have mass distributed from the center to the edge giving a lower moment, while your hollow one is both heavy and has the mass concentrated far away from the axis of rotation. Take a steel bar and spin around with it , versus a steel tube with a weight. You will see the effect very obviously.

Yeah it appears that centrifugal force meaning the force moving to the outside has the advantage...good stuff... which is why the IR socket makes a lot of sense to me.. and the hollow socket... using all of the weight outside of the center mass... Astro tools could make it a little Slimmer with more weight on the outside it's like throwing weight out while it's spinning and the spinning increases

Stiffness seems to be important. That's why the pipe sockets worked so well compared to the washer and lead ones. The lack of stiffness in those sockets will probably dampen the hammer blows.

I've found through hands on experience using many designs of those sockets on many stubborn crank bolts that it has something to do with the sockets ability to not bounce back between impact blows. Heavy alone helps keep it from counter rotation. Flywheel designs move the helpful weight from the center to act as leverage. Making that small weight be more useful than being on the socket wall. Your hollow design multiplied that by being light and even bigger in diameter (leverage). More power is transferred because it's not having to overcome extreme weight but the amount of weight used to hold pressure on the fastener between impact blows has leverage. I suggest a video with a deep socket with a bolt head welded to it. See how far it get. Then add a wrench to it with incremental notches to add weight to. Impact to limit Then add the wrench. Then weight to the first notch to limit. Move out till you run out of wrench.

I suspect what's best is the outside weight not being rigid to the socket. A little flex in the material means the outside weight can provide a 2nd intermediate blow. More or less doubling IPM.

The professor is correct on all points. Your last question has to do with the springiness of the long bolt on your test set up(and crankshafts)where the additional mass is able to counteract the lower force of a weighted socket in overcoming the bolt bouncing back on every hit. It's explained in the Ingersoll weighted socket patent.

In all 57 years as a mechanic --- when I ran into over-tight bolts or lug nuts, I always used a heavy walled, deep, six point, 1/2" drive socket and I noticed one interesting thing: If I wrapped my hand firmly around the socket as it was being driven by the air gun, it always took those tough nuts off a lot easier than when I didn't warp my hand around the socket and turn it slightly the wrong way. I could feel the socket hesitating and being held in a backlash position until the next hit of the hammers in the gun would send the next shock/impact down the shaft. I always thought that allowing a little space in the hex of the bolt/nut and the hex of the socket, allowed the socket to accelerate a bit just before it ran into the hex of the bolt/nut and THAT was where the mechanical advantage was --- by me allowing the slop or lash in the socket to be held open with my hand --- and let the socked hit with a little more velocity. Another thing --- if I squeezed the socket too hard, the effect was lost until I released it a little bit .... mebbee .... just sayin' ...... I'd like to see you make a hollow adapter to use between the gun and the socket - just to see if you get any improvement too.

The thing about professors is that they mainly operate in the theoretical. I'm just a lowly mechanical engineer but I think you have a couple things going on here. The point about rigidity is definitely true but most likely negligable. As long as a large amount of energy isn't being lost to deformation (i.e., the whole thing is made of steel and not, say, lead...) then it probably isn't a factor in these tests. I imagine the flanks of the nut are deforming more than the sockets typically do. As far as your observations, you are probably seeing a mix of flywheel effect optimization, and what I guess I might call good harmonic matching. The hollow socket cleans up because it has the right amount of mass and puts it in the right place. The heavier sockets probably don't work well because the impact can't accelerate them to top speed in the small space that they rotate in (the fixed impulse from the hammer doesn't deliver enough energy). The lighter hollow socket is being rotated to a higher speed, and the energy is being put into mass located farther from it's axis. Given two sockets of equivalent mass, one with a much higher moment of inertia around it's axis is going to be able to deliver more impulse to the nut. This kind of ties into my other theory about the harmonic matching. I imagine at some point the mass is optimal for the hammer speed and force which allows it to sort of bounce off the hammer with perfect timing and absorb the energy more efficiently. I would put this firmly in the speculative category because I simply don't know enough to be confident, but it seems right in my head. Anyways, big fan of where you're taking this channel and I would love to see more of this type of testing.

What is at work here are several factors combining to work together. #1 is a combination of flex and flywheel momentum causing a 'double whammy', especially with the IR flywheel socket. It is the opposite of what happens with a harmonic damper on the front of an engine, because instead of the flywheel being connected by rubber, it is connected with semi-flexible spokes of steel. When the impact from the gun hits, it sends both a shockwave and rotary kintetic energy through the steel. Some of that energy is also potential energy being stored by the flexing of the steel in the socket, then as the flex hits the flywheel, it sends the energy on through the socket and eventually hits the end of the socket which turns into kinetic energy at the lug nut. The timing of the potential energy release hits in a way that magnifies the blow rather than dampen it. This also explains why the I.R socket doesnt work as good on hammers with faster bpm or lighter blows, because the timing of the flexing of the material doesnt match the bpm of the gun. It is similar to using resonant frequencies to multiply forces and why anything large made out of metal has to have its resonant frequencies either dampened or mitigated in some way. Bridges, cars, etc. In automotive, cars are so quiet now and dont crack sheet metal as much because much effort has been given to address NVH (Noise, vibration, and harshness). Your lead filled socket didnt work because lead has a vibration dampening property to it- instead of transferring energy to the other side of the socket, it flexes and converts that vibrational energy into heat. Simply having flywheel mass doesnt work without the spring of proper steel. The large diameter, lighter weight socket work well because they transfer the impact torque more efficiently than a heavy skinny socket. It is the opposite effect of using a torque limiting extension. The futher from the axis of rotaion you get, the less force is applied to the steel socket wall, therefore less flex and more direct impact hit. There may be some harmonics helping the equation as well, as there is more surface area to resonate a shock wave.

I have weighted lisle sockets, they work great. Never had a crank bolt not come off using it.

There is one factor that wasn't mentioned in the video: from what the bolt is mounted to right back to the person holding the impact driver, elastic deformation is at play. (If you bend a bar and, after letting go, it goes right back to the original shape, that is *elastic* deformation. If it stays bent afterwards, that is *plastic* deformation.) As each impulse of torque is applied, there are complicated (elastic) shifts in the physical structure of everything involved. What I'm seeing is that, while adding mass to the socket decreases the 'forward' rotation for a given impulse from the impact driver, that mass also decreases the 'backward' rotation as the elastic deformation in the nut/bolt/mount tries to return to its original shape, against the mass of the socket. (If you look at the final angle of the lead-filled socket, you'll see that, while it is low compared to the other sockets, it isn't leveling off like they are. This *REALLY* should have continued on for twenty seconds at least.) What's more, we aren't talking about continuous force, but pulsed force, with a time gap between impulses. That is important because it explains why the socket with the spoked flywheel works so much better than without it, as there would be a significant amount of elastic deformation within the relatively thin spokes, so the flywheel itself won't be completely synced with the socket, extending the forward momentum to some degree during the time gap. (The length of the gap, itself, would have to play a part in the efficiency of the system as a whole.) I think that the following to changes should be made to the experiment: 1. Longer tests. 2a. Testing different spoke thicknesses/lengths/etc. 2b. Testing different flywheel masses/radii/hardnesses/etc. Does that sound reasonable?

It would be interesting to see if it's something to do the material use meaning the lead ones which are softer materials actually absorbing some of the blow if you made some that were the same weight out of actual Steel does that change anything

Armchair physicist here, weighing in. Where the actual physicist seems to have made an error is in assuming that the gun always applies the same force. But that’s not the case at all, especially with air guns, the motor is not using all of the energy in the line to spin up the socket. A heavier socket can be spun up just as fast up to the point of bogging the motor. This results in more energy being stored in heavier flywheels up until the weight that causes the motor to spin slower between impacts. I think the optimal solution is identifying the maximum weight the gun can spin without bogging at all and then positioning that weight as far out as possible to give the largest amount of torque at the moment of impact (distance squared). That’s why the hollow socket did better than heavier solid sockets, the hollow socket and the powersocket positions most of the added weight very far out without adding so much weight that the gun can’t overcome the inertia fast enough to store the same amount of force in the flywheel in the time between impacts.

I think it's all about finding the right resonant frequency that most closely matches the tool itself , and this subject is touchy for most physicist because everything is frequency even matter and throws just of everything you've learned in high school text books out the window. But if you think of the ir socket with the flywheel before you cut it, I'd be willing to bet if you hit it just right you get a certain amount of ding much like a tunning fork and same with the hollow socket. Maybe those two are closest to the actual resonant frequency of the tool itself. To test my hypothesis one could actually use the blows per minute to come up with a hz value, whatever that may be, then in turn create a socket that will resonate well with that hz value. Think of energy much like a tunning fork. I think Mr Tesla was right when he think in terms of energy, frequency and vibration.

@Torque Test Channel I might be thinking of this the wrong way but here we go. The flywheel socket has its mass farther out from the center. So it is easier to move when the impact happens. Theoretically then the same weight even farther out from the center would hit even harder. Your hollow socket had more mass that the flywheel but it was about the same distance from the center. If you had too much weight closer to the center then it is harder to get moving i.e. the two heavier sockets you used. The amount of force the impact has when hitting was less. An object at rest has the tendency to stay at rest and vice versa. There would be a spot where the flywheel will be too far out/too much weight and you would see diminishing return on the action. But it would be neat to see where the sweet spot is on weight vs. distance.

It’s a combination of leverage and mass. There is a sweet spot for work being done depending upon the torque of the power supply, like putting weights in the back of a truck in winter to gain traction. If you put too much weight on then the engine will not be able to perform as well as the work it has to do to move the weight outweighs the gain of traction. The reason hollow sockets work better than solid sockets is because you aren’t gaining weight but adding leverage. Like trying to lift a stone with a 1ft wood beam vs a 5ft wood beam. Just like a flywheel, the father away the mass is from the point of rotation, the greater the amount of energy it is able to hold at an equal weight. Essentially, because the socket is lighter the electric motor is able to do more “work” to the socket, thus gaining more energy to release with a higher leverage to release upon impact.

Great videos as always. I always wonder how do you guys record the torque number on a computer to be able to make the graphs. Seems like your gauge doesnt connect to a computer. Would love to know how that is done. Thanks

I have a physics undergrad so I will throw my suggestion in the ring. Fundamentally I agree with the physics professor, rigidity is key to transferring impact forces. Too bad you didn't test that in further detail, but can be done by just adding extensions. In theory extensions should decrease the torque. However, I think there are 2 factors at play here. One is rigidity, and that is what gives the Lisle socket its benefit. Second is resonance. Imagine you have an outer cylinder attached to the socket on an angular spring, so the outer mass can shift left and right relative to the socket. Then when you make an impact, the spring winds up (the outer mass rotates less than the inner socker) and then when you make a second impact, now you spring swings the outer cylinder at the same time as the impact wrench is swinging the socket. Now you have the additive torque of the impact from the impact wrench and the outer mass (Flywheel) swinging. However, because this is a resonance phenomenon, the spring constant and the angular inertia of the flywheel have to have the vibrational frequency match the frequency of the impacts. This is the equivalent of swinging your feet up and down on a regular children's swing. If you do it at the natural pendulum frequency of the swing, you end up swinging higher. In this case this is a rotational equivalence. I think that this is also the reason why the IR socket doesn't attach the flywheel to the socket all the way around but just at 3 points. They selected the strength of attachment to match the frequency of an impact gun (likely theirs). So again, two effects in place, one is is stiffening the socket itself and second is adding a secondary impact from the flywheel and as long as that secondary impact is in resonance with the impact wrench itself there is an overall additive effect. If they are not in resonance then the flywheel effect becomes irrelevant (think about swinging you feet randomly on a swing, it won't get you anywhere). That is the reason why the home made sockets gave various results, they weren't in resonance and had various impacts on socket stiffening. There are many ways to test these effects separately so if you want to explore further ping me and I am happy to suggest some specific experiments to do.

It's actually quite simple. The socket is still, it takes a certain amount of force to make it move....the heavier the socket the more energy is robbed to get it moving. With the hollow socket you found the sweet spot at least for the weights you tried. Once the energy remaining in the socket is transferred to the bolt, minus the energy needed to get it moving, that is your result. It's like a supercharger on a car, your engine loses hps the bigger (or more accurately the power needed to rotate it) the supercharger is, then you add in the gains of the supercharger. If the supercharger robs more power than it yields, it becomes superfluous just like big leady!

First saw these when I worked in auto salvage and I remember saying "The mass is in the wrong area. If F=MA and A=0 then changing M shouldn't matter since anything times zero is not. You would want the added Mass in the hammer since that's where the acceleration is coming from." and getting the old deer in the headlights look. It might help carry the force longer but it should also slow down the acceleration since the hammer now has to move a larger mass with the same force. I do have a University of KZfaq degree in Physics here so I would check my maths. Based off my sample of one random socket that was at work one day, I wouldn't waste any time on these.

I would like to put in a layman's terms. In the flywheel and the hollowed style sockets have a tiny bit of flexibility between the main body/core and the outter wall area. That flexibility causes the outer wall to slightly lag behind the core. When the core stops, the outer wall still has energy to still move in the direction of travel. So there is extra force going to applied to the core. Here is another thought on the matter. Depending on the impacts per minutes or seconds, that will affect things too. If you can find a combination of impacts and the right flexibility setup, you could increase the force. One way to test this idea out is take an adjustable speed controlled impact driver and the same socket and see what the results are by varying the speed one setting at a time.

I mean it might have something to do with the amount of inertia vs the amount of mass. The hollow tube would have more rotational inertia because the mass is further from where it rotates, but would not need as much additional mass to achieve this inertia. There could be several other things at play here but this would make sense. Also there is necessarily some clearance between all of the parts involved, so maybe this plays a role with the amount of momentum it builds up before it transfers torque to the bolt.