Torque Sticks! High Speed Video Helps Reveal the Truth 

*To be clear we did use a cordless high torque in testing as well **5:40**, and it's just as bad (30-50% over)* The separation of the lines is what you want to see like shown with air tools, it means the bar is taking up the impact force by twisting instead of transmitting down to your lugnut. The lines staying together during an impact blow means the bar is not working as it should to limit forces, like it appears to with cordless tools.

Some 20 years ago when I worked at a tire shop (this is the second video in 24 hours to make me nostalgic for those days...) our boss occasionally did a demonstration on how innacurate torque sticks are by running a lugnut on his car with a 100ft lb stick and hammering it for like 10 seconds. Then used the pointer style torque wrench to try to remove the overtorqued lug and pulled it until it pointed to 110 to 120 ft lbs to show you absolutely could over tighten lugs with the torque sticks. He'd wrap up by bringing one of the non-techs in and have them try to remove it (usually one of the gals at the front desk, someone who didn't work on vehicles) and told us to imagine our family member on the side of the highway trying to change a tire with over torqued lugnuts.

Taking down of old videos when better information is available is why you guys are amazing and respected

You guys and Project Farm are my go to channels when I need an unbiased and true review on a product. What y’all guys do is amazing, and I have a huge amount of respect for refusing sponsorships and donations in order to maintain your unbiased brand. Keep doing what you do TTC, and thank y’all for all of this in depth, FREE information

Like all spring systems, the torque stick will have a resonant frequency. If the return bounce from the nut-end coincides with the applied hammer-blow, there will be additive mixing, thus increasing the applied torque to the nut. Perhaps torque-sticks were only designed for air-tools that all share a common hammer rate.

Excellent video! Never would have thought about the differences between air and battery impacts and their effects on these sticks. Great thing to keep in mind.

At our shop in early 2010s we always dropped 20 pounds down on the torque sticks, e.g. if it was a car that called for 80 ft lbs we ran them down with the 60 stick, gets the wheels tight enough to drop the vehicle for final torquing without the chance of stressing the lug. It worked pretty well and cut about three to five minutes a vehicle.

Fantastic video. From an engineering/physics point of view, the key takeaway is the jerk (rate of change of acceleration) is different for the two tools and for the dyno vs no dyno. The electric tools have a different impulse due to their striking frequency. So in a duty cycle comparison - about the same power/torque over an average measurement, but with different jerk characteristics and slightly different physical transfer of torque. The difference with your torque tester is similar - the nut on bolt will have a stick/slip release to torque and then a big increase in torque when butted up to a jamming surface which is different to the fluid buffer in your system. The torque to force conversion through the fluid is acting like a dampener to the impulse of the hammer. The hysteresis of that is giving you a mechanical advantage.

For tire shops, these save a lot of time. The idea never was to get it "right" by just snapping on a torque stick, but for that torque stick to get just under where it needs to be in order for a torque wrench to finish the job without needing 20 more turns per lug.

Thank you for these tests! I am an automotive professor at a local college and I always am looking for visual ways to show students concepts - I will be adding this video to the required 'readings' for their first semesters!

I always use my thinnest torque bar (like 65 #FT) because then I know it's tight enough to put on the ground but probably not tighter than the torque spec that I will reach with a torque wrench.

we used to use torque sticks everyday and as the electrics started to come along torque sticks went away, I have always been told they don't work together and this is just proof, still good for the lube kids to prevent over torqueing. great video as usual.

Love your willingness to go back and correct a video and show everyone you may not have gotten it completely correct the first time.

Well crap, I use torque sticks with my cordless impact. Now I know why most of them click without moving when I use the torque wrench. Glad I watched this video!

Removing the other video for updated info is awesome. There's a lot of bullshit out there that has since been updated but not removed. Kudos to yall for that.

Really appreciate y'all not just updating us with this info but also removing the older, potentially misleading video. It takes a lot of commitment and integrity to produce and maintain good data like this

I bought a set of Snap-on torque sticks when they first came out. Wanting to make sure that they were accurate, I followed common sense and the included directions. The air pressure in the system should be consistent and verified to be adequate. The air impact gun should also have an internal regulator device (dial or knob usually) that will be used for repeatability/consistency. Set the air impact gun's regulator to the lowest setting that will allow the desired torque to be achieved with minimum overshoot. Use a calibrated torque wrench to verify that the lug nuts have reached the proper torque. Once you have done this process, you can be assured that the air impact with the torque stick will apply the needed torque within an acceptable +/- range from then on. The important part is that all the lug nuts will be set to the same torque, at whatever that +/- calibration is, which should be very close to the specification. Once you get used to the feel of how long to pull and release the trigger, it becomes very easy to get excellent accuracy and repeatability. The torque sticks made the slow, tedious job much quicker and effortless to do. I did suspect and confirm that they are only to be used with an air impact gun as mentioned and demonstrated in this video. The cordless/electric impacts are delivering a more constant rotation which does not allow sufficient torsion rebound to occur within the torque stick and the harmonic frequency intermittently "lines up" to make the torque stick act almost like a solid extension which obviously defeats it's intended design. I verified that there is no way to eliminate this tendency to anywhere near a satisfactory level to achieve accurate torque from lug nut to lug nut with a cordless/electric type impact gun. I just make sure to final torque all lug nuts with the air impact and leave it at that. Maybe one of the cordless/electric impact gun manufacturers will someday figure out how to make an accurate torque limiting gun with a built-in torque sensing system. Hopefully it will be affordable as well! That is a tall order in my opinion.

Ton of respect for the methodology. Honestly very few videos have relevant info for my life, but I'll take a big analytical inside scoop of how anything really works in practice. I hope you guys keep the method & branch out someday. You'd probably be good with this who quarter turn back to lock the chuck thing that went around recently

I can remember when we started using torque sticks back in the early nineties at the dealership, we were told by GM that they should only be used with single hammer style impacts and not twin hammer.

Here's my thought. The BPM of a cordless is higher which does not allow the torque stick to return to it's neutral position between blows. When it hasn't returned to neutral, it has a preload on it. The stick not returning to neutral means that it's preloaded. A preloaded stick acts more like a thicker torque stick in the way that it transmits more torque to the receiving end and less twist from each blow delivered. The more you twist the stick, which is a spring steel I imagine, the more torque it takes to twist it (until it's yield point anyway)which would allow the higher BPM impact to transmit more torque to the nut on the other end. In other words, when the stick is already twisted some, the impact can tighten more than the sticks rating which is done from the neutral position. The more you compress a spring, the harder it is to compress. I believe the same rule applies here. If the cordless impact BPM were slowed down and the stiuck was allowed to return to neutral, I tihnk the torque stick would be more effective. If you have a really low torque stick, try it on the 6727 on #1 and see if it limits the torque more effectively with the lower ipm. Or compare a high imp impact to a low ipm impact on the same torque stick. I'm no scientist, but that's what I think.

What a well designed experiment! Very nice work!

Those sticks and the steel tubes were great demonstrations of how these torque limiting extensions work.

I am so appreciative of this channel and the testing y’all do.

This is something I wish we saw more of. People actually taking down videos when they are found to be incorrect or incomplete and replacing them with more valid video.

Beautifully explained and tested. I don't see anyone doing it better. Thank you! Subscribed.

Great explanation and testing. Finally understood how they work

I just love the scientific terminology "sort of" and "kind of", way to go!

Thank you for full filling this! I made a case study over two years ago proving that cordless hits too fast awesome

If I had to guess I'd say its a combo of the anvil weight and the IPM. Using your rope and plate analogy it's like a halfway between the steady twist and smacking the plate (or like a machine gun constantly hammering the plate, giving almost zero time to twist back), not giving the material in the torque stick time to return from its partially sprung state.

Proper use of torque sticks is more than at what point they stop giving, Its also the feel in the gun that the operator has to get used to that tells them when to stop. You have to get used to feeling the slightest kickback, sort of like a wobbly feeling.

Excellent video! I've had a set of these torque sticks for many years, and have trusted them blindly for my home garage use. I've always done the final snugging with a traditional click wrench, though. They are great for speeding up a quick tire rotation while I do an oil/filter change. Just subscribed!

Very cool! Glad you came back and did this again!

That analogy is perfect. It makes it super easy to visualize.

Excellent video. This tells me that the old method I use of turning my impact way down for just snuging the lug nuts on before before using my impact is working well.

I've always used one ~20% or more lower than the torque target then followed up with a torque wrench. eg. use an 80ft/lb torque stick for 100ft/lb final torque. This way the lugs are tight enough and evenly torqued to lower the vehicle but not overly tightened.

Super cool video. I always use a wrench on my lugs because I'm just a home mechanic, but the physics of this is super interesting.

I just experienced overtorque using a 80 ft/lb stick and a cordless impact yesterday. Thanks for the explanation.

For lug nuts, I just use my impact on "low" until I feel the slightest resistance, then go for the torque wrench atchet. I had an air impact that on its "low" setting was almost spot-on 85 ft-lbs, so the torque wrench never made over 1\20th of a turn when I was done (I was a tech at the time).

Thoroughly enjoyed the video. I knew there was a reason I didn’t want to use a impact drill at work instead of the air gun. Both weigh the same but one is just nicer

The50'skid did a test with torque wrenches a while ago and used two different Milwaukee cordless impact guns. He found that the smaller gun was highly inaccurate when torquing bolts down, but for some reason the more powerful gun was almost dead on with the sticks.

great video ,I use a Makita impact or a air powered impact and torque wrench, it takes only a few minutes to check wheel torque, i use to do a few thousand wheels a year when i worked for New Flyer bus company, we'd install the wheels and use a 3/4" high powered impact and then 2 guys and a 1" drive torque wrench and found far too much error, employees lying about the job, so we eliminated that by using a gun by Hytorc ,dial in the spec you need ,get it done and paint mark each wheel nut record it the inspection book ,inspector signs it off , one person needed instead of two and the problem was solved , I gave away my torque sticks to my nephew 👍

The cordless doesn't let off to zero torque between hammers like an air gun does. That probably has the largest effect on the function.

1 - torque sticks are a gadget, snug up the bolt and use a torque wrench; 2- one should never press on with the impact after it snugs, that's a good way to over-torque or gall the threads.

Excellent video. In the hands it always felt like my Milwaukee was too much beans for a torque stick. I would use my air gun with a torque stick and send it without a torque wrench check after, or I'd snug them with the Milwaukee and torque wrench them tight after. It's nice to see science match feel.

I found this channel after I stripped my bolt by applying the correct torque spec on my bmw's oil nut thing. I never learned why but it's an entertaining channel

I'm curious as to if they keep their properties over time

I use them WITH my cordless impact for wheels only! Never over torqued any lug nuts with them, as long as you only give them a sec or two per nut and no more! Works every time and saves me a ton of time and hassle from having to torque things manually.

i wondered how they worked, thanks for the video !! i have used an electric impact, then checked/finished with torque wrench, and pretty close.....i havent tried with a cordless yet.

Very good video - part of the issue with cordless as you said is frequency - best is to use a really long extension (or bettwe yet several torque limiter in series) added to the torque limiter to help with frequency response.

I always like to think of it like I'm trying to put a very specific hole depth in drywall. I can't easily push the drywall (regular wrench), but I can punch the drywall (impact gun). Torque sticks are like using different thickness pillows to soften my punches a little allowing me to adjust how deep the hole goes.

Nice engineering lesson! Same is true on drive shafts on vehicles. Ever noticed that on high power vehicles the drive shaft is kept as short as possible? Subarus having equal lengths shafts drive nicer than unbalanced shafts? The Tesla Plaid not only gets rid of the differential in the read but also skips the losses of the traction control used to factually balance the loads. Summing up: Any extension will reduce torque so it it is critical use the torque wrench!

My assumption is that the hoses bulge slightly with each impact even if the fluid is incompressible. The solid backing of the welded setup lets it hit as designed.

Much respect for taking down the old video, even though it could still make some good money. 👍

That was a bit of information I did not have an excellent demonstration so that I could figure out why thank you very much

I admit up front I am not a mechanical engineer, but I think the answer regarding your 3D printed fixtures is simple once you see what I am referring to based on your explanation of how the torque sticks work. Thinking about your 3D printed 'wire' indicator versus your 'tube' indicator, I think the reason why it behaved the way it did is BECAUSE of your 3D printed support. From your video these torque sticks work over the entire length of the tube. Your wire indicator (while welded on the ends) had those supports in the middle of the tube which is where the limiting mechanism was happening, while your 'tube' indicator was self-supported the entire length with no supports in the middle. This also explains the behavior of your 'wire' indicator with the cordless test, as your 3D printed fixtures were then 'slipping' on the tube due to the higher impact rate (for the same reason the torque rod didn't work) I had wondered not only if they work but how they did, so your video was very informative! While your product reviews are great to watch and helpful if/when I ever need to replace a tool, these "How it Works" videos I think are even better as they show not just what/how somethign is working, but WHY it is working the way it does. Looking forward to your next video, whatever it is!

i bought master force torque sticks and used them on my truck. my wheel loosed and started to come off a couple weeks later. i tested masterforce 120ft/lbs stick against a snapon stick and found 43 ft/lbs light when torqued with a mac 1/2" air gun and checked with the digital snapon torque wrench.

I figured this concept out the cordless impacts on doing large truck ubolts. Using a 1 inch drive air impact you might get the nuts to a couple hundred foot pounds because of the way the gun hammers. But the speed of blows on the 1/2 Milwaukee high output 18v impact, the gun is hammering the nut again before the torsion in the long ubolts rebounds and I can consistently get at or close to 475 foot pounds then finish to final torque with a torque wrench. Such a time and back saver.

Outstanding work!!

your guys videos are so informative bro.

This is a good demo of modulus of elasticity in torsion/shear. Thr stick is acting like a spring, storing the enenergy between the driver and bolt. Open end conditions and the impulse of force change the behavior allowing more force to transfer through rather than be stored and transmitted back to the user.

Very interesting. This is why I love this channel

When I first saw the man hanging on the rope, I was like, "Oh no...this went dark, quickly..." Glad to know he is still hanging in there! This was a great representation of torque sticks! When these sticks first came out, the vast majority of the auto shops were using pneumatic impacts, so these were designed for use with those types of impact guns. And the designs of those impact guns were slow on changes. Even if power output slowly increased over the years, the bpms stayed relatively low (well, low compared to the electric impacts of today). Not enough to make a huge difference to invalidate the torque sticks over the years. Fast forward to today, where electric impacts are more common with a wide variance in power and speed. I suspect that the stick is not allowed enough time to spring back to the neutral position when used in conjunction with high power/high ipm electric impacts. So it gets hit again in a preloaded state, causing any further impacts to force the torque stick to be out of the normal working range. The same goes for lower power/speed impacts, not enough beans to twist it hard or far enough to reach the torque range desired. (But what do I know? I'm just a grease monkey! 🔧🐒) You demonstrated that with that high ipm impact driver very well! The high ipms of electric impacts (3100 ipm, for example) is well above that of pneumatic impacts (take the well-recognized IR 231, with the spec sheet showing 1,200 bpm). In other words, torque sticks are for pneumatic impacts, silly batteries!

Neat. The one big thing i'm taking away though, and correct me if i'm wrong, is that I should over-rate a torque stick when using an electric impact tool vs. a pneumatic one, to prevent over torquing lug nuts before final torque. Or I can stick with my current method of knowing that setting 2 on my 1/2" Ryobi will do about 60 ft-lb after 4 ugga duggas. :D

I always get such a weird look when I bust out my torque sticks for tightening head bolts, now I've got a video to back myself up that I'm doing it right

I like that you used a bar and a rod to show the flex. It would be interesting to see a segmented rod. Just cut that rod in pieces and use more supports to line it up. Curious if it’s a twist or a wave.

7:48 when I worked for Penske servicing semi trucks we relied EXCLUSIVELY on torque sticks and a 1" air impact for lug nuts. We just flat out did not have a torque wrench for those nuts. granted they go up to 500lb/ft and it's not gonna cause a wheel-off if you only hit 495 on one, but still. And hell half the time I didn't bother switching to them. I found during my days as a Goodyear CTSC tire slinger that 8 ugga duggas from a 1" air impact was pretty much right on the money. 7 too few, 9 too many. So I usually just ran 'em down 8 ugga duggas and called it.

I personally like torque sticks. They seem to work well with my ingersoll impact. Comes down to what are you comfortable with it leaving the shop with. If a wheel comes off it’s on you

I think you might be seeing some effects from the hydraulic fluid in your results. it takes some amount of time and force for fluid to flow, however small and it could be effectively damping the tightening movement of the nut. a 1/2-13 nut moves axially a bit more than 2 tenths per degree of rotation. Another factor could be the spring force of the container. as that hammer blow transmits into the fluid it probably sends a nice spike of pressure which is going to flex anything it's pressing against. that's the fun of testing, though. factors that are almost always negligible become a huge deal if you aren't sure how much they contribute to the results.

It would be awesome if they had some form of usage scale. Like you said electric impacts hit faster, so a value of not to “exceed x hits per second” or something. But I imagine that would also require the tool to have a “like” value

I discovered this system about 40 years ago. It was a rare tool at the time. A Swedish company (Momento) specializing in sockets produced torque sockets. They weren't extensions back then. I don't know if they were the inventors of the system, but it really worked well and with enough precision to not have any problems when tightening the wheels. I had a problem once, but it was my fault. By replacing the alloy rims for the winter with sheet steel rims, the screws, which had part of the thread a little rusty, falsified the measurement and the tightening was not sufficient. Apart from that, I could always ensure easy disassembly for my customers in the event of a puncture, without risking losing their wheel. I have often demonstrated this to curious or worried clients. :-)

Brilliant presentation. Having observed the effects for years, it’s really cool to get a better understanding of how and why it’s happening

Nice science. I have one of Snap-on's 1/2" cordless. It has its own form of torque limit. three settings 100, 200, max I set it to 100 when using torque sticks. Works well and under torques them as long as I don't hit them longer than zipping them on. Like you said, zip um on and your good.

If you're using torque sticks to torque lug nuts like suggested in the video, zipping lug nuts down and then torqueing to spec, I'd suggest just using a little 1/4" impact driver, zip em down snug, then torque. That's what I do, I drive my cars hard with sticky tires, I don't use hub rings, and I have zero problems. In fact I believe it is better to snug each lug before torquing as it helps the wheel center and seat with the taper lug nuts vs running each one straight down to 100ft/lbs.

I've found that if I'm torquing my wheels on my F150 to 150ft-lbs it's best to use the 130 or 140ft-lbs torque stick then finish the torque by hand with a torque wrench to limit the work required by hand. I too noticed the 150ft-lbs torque stick on my Milwaukee impact driver over torqued the lug nuts

This was an excellent video. Very informative. 👍👍

Can you guys look at some fix-it sticks torque limiting drivers? Both fixed and adjustable. Thanks! And keep pushing Milwaukee on their sketchy 1/2" redesign. You guys rock.

I was a certified automotive technician for 20 years and I found that the torque stick isn’t so much about getting the exact correct torque, it’s more about getting all the lug nuts the same torque and not over-torqued. It also makes a difference whether you hit the sticks with the same amount of impacts per lug nut. If you hold the impact down for 5 seconds on one lug nut and 10 seconds on the other the torque won’t be the same. It makes a huge difference in warped rotors and damaging threads on lug studs. I always use a torque stick unless I’m on the side of the road in a pinch and don’t have one.

Excellent video. Thank you. Answered my question can i use torque stick with a battery powered impact. No

I have a dewalt 1/2 inch impact (forgive me for not having the model number memorized lol), but I use torque sticks on the number 2 settings. It's pretty close to the target torque level with the ones I use at least.

We have a Tame hydraulic torque wrench at work. The specific one we use has three torque settings, as the specific item being torqued has three stages of torque. One day (recently), a coworker decided to use the "loosen" function to torque the nuts in question. The nuts have a maximum torque of 2400 lb-ft. The "loosen" function (break away torque) of the wrench can create a maximum of 3800 lb-ft. He almost destroyed the engine by continuing to torque on the "loosen" setting. And before anyone says "it should only work in one direction", consider the possibility of reverse threads.

The "torque sticks" are springs as you pointed out (torsion bars). Springs have a resonant frequency,which is why the pulses per second affects how well they work. Too many pulse per second and the spring can't dissipate the absorbed energy by returning to it's unloaded state.

I have big trucks at home. And use a onekey milwaukee impact with a 80 ft lb torque stick.. i find the lugs are within 10 foot pounds.. the onekey impact I can dial down the mid torque to a reasonable amount of power. I still check the lugs with a decent torque wrench.

I would liken it to using a breaker bar to loosen a nut. If you hit the end of a 24" breaker bar with a hammer to attempt to shock a nut loose, a lot of the energy from a hammer blow will be used as work to flex the breaker bar. If you hold tension on the breaker bar, then hit it with the hammer, you are more likely to move the nut because the breaker bar won't absorb as much of the energy into flexing because it is already tensioned and can't move as far as unloaded when the same force is applied. The cordless impacts are like a tensioned breaker bar because of the high IPM. The high IPM essentially holds tension on the stick which allows torque to me transmitted to the nut instead of absorbed by the torque stick twisting, which happens on traditional pneumatic impacts that don't hit as fast.

I think driving a nail into a springy board could be a more relatable analogy for most people. A stick with a higher resonance frequency might be better for cordless tools.

Thanks for an informative and interesting video! 🌞

Its a great demonstration, if you were to do something similar in the future the split tube would show the rotation flex better if it was solid for the majority of the extension, the current setup is halving the effect by being in the middle. Love the channel and the content. keep up the great work guys

It's nice to know that extensions on an electric impact driver rob less force than l expected. I've got a few hex to socket adapters that have a six inch extension on, and l always thought those really cut down on the power transmitted, but l guess this is why l never really noticed any weakness in practice

Excellent video! I’ve always enjoyed your videos but this one demonstrates high credibility. Taking down a revenue producing video that might have incomplete info is very honorable. Thanks for all of your excellent tool tests.

Well that saves me from getting torque sticks for my 1/2 cordless driver. Thanks for saving me money.

Could you test torque stick accuract with different impact guns? Cause some guns have different blows per min, wondering how that would factor into the equation

I have also noticed with torque sticks they work better on pneumatic then Cordless always over torques on a Cordless tool with torque sticks @Torque Test Channel

Great vid, I wonder if in like 2-3 years we’ll get another with an even faster camera revealing more visual data

Excellent explainer! I got it straight away

I've been thinking about buying them and I use a cordless impact, so thanks for saving me $.

In factory assembly of all types of machines, the electric drivers (hand and robotic) have precise torque settings. Old school assembly uses Philips screws, which are designed to slip out at the correct torque, reducing build time.

More impacts per unit of time would not give the stick enough time to fully rebound, so it ends up preloaded before the next impact, ultimately increasing the average torque. Makes a lot of sense. Thanks for the vid.

Excellent analysis and reporting! One question, since the electric impacts will continue to torque the nut at a given value of torque stick due to impacts per second, would going down to the next smaller rated stick give results that would not be in danger of over-torquing the nut?

These videos are so helpful. I love the analysis on why torque sticks don't work with cordless wrenches. Makes sense and it's very valuable information. Thanks for all the hard work you do. It's greatly appreciated!

A company I work for decades ago had a Skidmore Willhelm bolt tension tester as a demonstration tool in the field. I used that instrument many times. If I were torque a nut on a bolt to the prescribed torque setting and then loosen that nut and re-torque it again, and the clamping force would be reduced even though the nut was torqued to the specified amount. The conclusion was you should not reuse a nut. In this particular demonstration a new nut and threaded fastener would be mandatory. Even oil from your skin touching the fastener threads affect the torque or clamping force.

Confirmed, when the world goes slow-mo, you hear epic music play in the background.