If this video helped you, please consider clicking on the THANKS button above to support my channel 🙌 PLEASE NOTE: there is an editing mistake in this video - ALWAYS set the specified torque by twisting the handle BEFORE measuring the length from the head. Otherwise your measurement will be wrong :) thanks!
@@ClaudeSac Tbh hitting the thanks button wouldn't have occurred to me if he hadn't mentioned it - and I feel indebted for this invaluable and money-saving advice so it meant I could show my appreciation in some small way! With 5.7k likes, a small percentage of donations would really add up and encourage more advice like this. A few quid is a lot less than paying someone for the info, or recalibrating or replacing a tool!
Nice tip, I will be re-calibrating both of my wrenches. One tip I was given more years ago than I care to admit was to turn your torque wrench back to zero after use, relieving the tension on the spring. Cheers, Geoff
At work, we had our torque wrenches calibrated yearly. As an experiment, I bought a really cheap one and left it wound right up for three years, it passed calibration.
@@paulhawkins6415 "experts" say "don't keep your magazines loaded with ammo, as it will weaken the spring". Yet militaries around the world store full loaded magazines for who knows how long.
My magazine spring began to misfeed my H&K USP .45 in less than a year of being my always loaded bedside gun. Changed the spring, problem gone. @@savage22bolt32
You should measure the distance from the drive (where you hang your rope) AFTER you set the wrench to the appropriate weight because the handle moves in slightly toward the drive as you turn it. Also, make sure the wrench is perfectly level. Good tips, though. Thanks for sharing
These clicker type wrenches are typically calibrated for the force applied exactly at the middle of the grip (and it does matter, there are a few videos explaining and clearly demonstrating this), therefore that should be the point you hang your weights from and measure the distance to. Ideally, one should test different hanging positions on the handle with different weights at both ends of the wrench's torque range, find the position that gives the most accurate results throughout the torque range and then only apply force at that exact position during normal use. Whether it's going to be the middle of the handle or closer to either end of it really depends on each specific wrench model.
A good post and usefull vid .👍 Most cheap high street wrenches are way off and need calibrating. I Used to calibrate equipment as a tech support engineer both eletrical from fluke meters to torque wrenches Ultra light 6ft lbs too 500ft lb long bar. Good advice for a rough home setting. I'll just add to get it spot on you ideally need to check the lowest, the mid & the highest settings as the spring tension accuracy can vary hugely and may show that the tool is no longer accurate on all settings. Most common reason is because people dont reset the wrench back to its lowest setting after use and just leave it for months with the internal spring under constant load.
@rtg8point858 for the imperial the math is the weight ÷12 × the distance along the torque wrench.. if you go with 12 inches, the ÷ 12 × 12 nullifies itself, so the result is whatever weight you choose, that's what you set your torque wrench to.. no math involved at that point. Hope that explained it for you 😁👍🏻
Good tip! You could also extend the handle with a pipe, or make your own tool to hang those weights at specific distances every time you do this. Ie. a two foot pipe with notches for the string at 12 and 18 inches, choose your weights according to the specs on the wrench. Super simple calibration every time. You also don´t need so much weight if you extend the leverage, so that might be a thing too.
Great video. I'm going to try this out myself. One note: I think it is important for the torque wrench handle to be parallel to the ground. If it isn't parallel (or as nearly so as possible) then the effective length is different from the measured length thanks to vector trigonometry.
Yes sir you’re spot on! I think it’s important to be as accurate as we can, but also remember that even if things aren’t precision perfect - it will still be more than good enough for what we do :) you won’t snap bolts being a bit over nor will it cause an engine to fail being a bit under the specified torque. Thanks for sharing!
@@VintageEngineRepairs Just as a follow up, if you're within 10˚ of horizontal you'll be within 2% of accuracy, which is equivalent to +/- 4mm on your length measurement. Given your string is about 4mm in diameter, that's plenty of precision. If you get out to 20˚ you're still within 7% of the calculated value, but it starts to rapidly fall off in accuracy after that.
@@daveatutubeAs the purpose is to calibrate the torque wrench, you want to do what you can to achieve max accuracy, and that does not involve having the handle at an angle.
@@VintageEngineRepairs You did not mention it, but did you weigh the rope with the weights? For that 1 or 2 % accuracy, the rope may make a difference. Not moaning, just checking/mentioning. Also, could we all say pound-foot, like Newton-meter? That's moaning ;)
This is the best DIY demo I've found. The process is not that complicated, although for accuracy the right angle distance and mass need to be accurate. I've often wondered how much ambient temperature affects this clicker style of wrench. In the end, most of the time a variance of 5% is fine. Often it is a comparative tool, so even if it is out a little, all the bolts will have the same torque. These days we tend to go overboard with torque, although the margin for error in aluminum housings can be small.
Thanks for watching :) I agree, for what we all do 5% even 10% is not a problem. Heck you could be even further out and not have any issues. If it was on a a spaceship then it’s a different ball game. This gets you very close, easy to do at home and will be far more accurate than doing it by hand :) thanks for watching!
I agree that this is a clever way for diy calibration. Although not complete. Even though the style of torque wrench you show here is common, there are a lot of different ones. And the method of adjustment also differs. Some do have the screw you show now, but also a lock screw for instance. A lot of professional wrenches also feature an adjustable scale. Typically you adjust the screw you show in the video to set max torque, and adjust the scale for minium torque. Most cheaper wrenches have a fixed scale and I would recommend calibrating for the range you use, as it will be hard to get it right all along the scale. Most professional torque wrenches are supposed to be within a 3% margin along the full scale. Typical calibration is done at 0% 60% and 100% force. It will be hard to get it to within this spec with this diy solution. But it's definitely better than not checking it at all. The 3% margin is also ludicrous if you ask me, how you hold the wrench, how you apply force, is your bolt dry or lubed, etc will have more effect on the end result the a bit bigger margin on your wrench. Bear in mind that the electronic force gauges might also not be accurate. Especially cheap models can have quite some deviation. So you might want to check the force gauge with this method before using it to calibrate. In short, good method for approximate calibration with little expense. But not suitable for critical work. Just my 2 cents as someone in the tool business, including calibrations.
The wrench handle should be horizontal; maybe it's the camera angle that makes it look like it's pointed down, which would make it require a higher torque to click off.
One thing not accounted for with this method is the weight of the handle, which is small but not zero. In the big picture it's likely negligible. I suppose one could measure this with a simple experiment. Suspend the wrench with a string looped around the center of the head, then support the handle end with a scale. Multiply the measured scale weight by the right angle distance from scale contact point to string, and you've got baseline torque with no extra weight added.
Yeah I agree with you, it’s negligible, as mentioned before, for what we do, it’s not going to make a difference. Most torque wrenches come with, from memory, +/- 10% accuracy. Thanks for watching and commenting, it’s always good to hear other people’s opinions and ideas :)
Ah, but then you'd have to add or subtract the weight of the handle depending on whether you're pushing it up or pulling it down when you're actually using it. If the bolt is vertical and the handle is rotating horizontally then no correction would be needed.
Very cool, Tom! I knew a specific torque was dependant on weight and distance, so your procedure is brilliant. Those two figures and the conversions are all that's needed. Way to go!
When I was taught to use a torque wrench many year ago. We were told that the break in the knurling or the thin band of knurling was where your middle finger was supposed to be placed. The reason given was that this represented the calibrated distance from the drive head to achieve the most accurate torque. After watching your video, that make sense and would cause me to use the as a reference when calibrating. Either way, I really liked the video and thanks for the cool trick to add to my knowledge.
I don't think it matters where you hold it, the wrench still has the same accuracy just the force you need to apply will differ slightly but it will still click at the same nut torque force
@@stargazer7644 It does matter where you hold and calibrate the torque wrench. You are meant to apply the force at the groove that all of these torque wrenches have. They all have them for a reason. I know that may be unexpected because a torque is a torque after all, but these click-style torque wrenches complicate things somewhat. There are actually two torques in play here: one torque at the head of the torque wrench which is wrenching on some fastener, which is what we want to measure, and another torque at the "elbow" between the head and the handle. The torque wrench actually measure the torque at the elbow, which is where the clicker is, and we use that to stand in for the torque at the head. That works fine if we calibrate things right to give us the right numbers. However, the calibration assumes a particular ratio between the handle length and head length. To gain an intuition for this, imagine a particular torque wrench that has a particular torque dialed in. In your imagination, apply a torque at the groove and make the wrench click. Now, leaving everything else exactly the same, modify the wrench to lengthen the head and shorten the handle, but let's leave the total length the same as before. Let's say the handle is now half as long as it was, which means that the elbow will now be approximately half way along the wrench. Now, apply the same torque as before. Will it click? No, it won't because the lever arm to the elbow is half as long as it was before. You will have to apply twice the force to make it click now. That shows that the ratio between the two lengths does matter. Going back to the original torque wrench now, if you apply the force at a different place, you will be changing the ratio.
@@stargazer7644 The force from your hand should be applied at the same point that the calibration force was applied. You might as well use the groove that is put there for that purpose in every single click-style torque wrench. I know what you are saying. A torque is a torque. But that doesn't apply to click-style torque wrenches, as I explained above, because the "elbow" point, where the clicker is, is not at the same place as the "socket" point. The actual measurement point (the "elbow") is not exactly at the same place as the intended torque application point (the "socket"). For other styles of torque wrench such as a digital one or a deflecting beam one, then yes, it wouldn't matter where you hold it because the measurement point (the transducer in the digital one for instance) is at exactly the same place as the socket.
Minimum spec on my Torque Wrench was 20 FT Pounds. I didn't do much math and still calibrated it. I though to myself "Foot, pound" Therefor 1 Foot away from the head should required 20pounds of load is what is needed to click it at the 20Foot Pound setting. So i filled up a bucket with 20 pounds worth of water and i was able to perfectly calibrate it. *I was able to verify this theorie with a new one and it clicked right when i was laying down the handle of the bucket on it.
I dont want to explain the reason, but ... ... always calibrate with the force of the weight where the manufacturer marked ist at the handle. (If you can find a mark = It is the middle of the area where your hand will be !) (You see it here in the video) If you choose an other point of the force from the weight = Calibration is wrong. Additional information = Please no discussion ! There is a reason why simply choose a nice distance from the middle of the squere Socket adapter to a nice distance for an easy calculation ... ... will result a wrong calibration ! See other videos that explain the reason (=it is inside and we cant see it and our brain always refuse these reason. But it is true = middle of the grip zone where your hand will be (often good manufacturer mark these area). Discussion with these RUclips channels (or a maufacturer or these mechanical torque wrench with the easy inside construction. Remember there are Split beam torque wrench (= I never ask one of these manufacturer or saw a calibration RUclipsvideo that explain these physical rules for calibration. But I bet force of the weight at the middle of the handle).
Great video and so simple to do. I have been told by multiple tool shops that the smooth ring in the handle is the factory point where they test the torque wrench. Not sure if it is true but you might as well use it as a fixed point for future calibrations so you get the same point each time. You'll also notice that the ring is slightly closer the end of the grip, this is because when we pull on a handle at 90 degrees more of the force is concentrated towards the last 3 fingers (middle, ring and pinky) on our hand. This enables us to grip something very tightly while still being able to use our thumb and fore finger for other things. Try it out.
Yes, I noticed on your last click test by hand you probably without thinking positioned your hand right over where that band is on the handle. Cheers, great video
Yes, typically the handle is marked for this purpose. Not just for factory calibration, but also for recalibration. Different brands use different marks, but I would expect the clear ring to be the mark in this case.
when you turn the setting handle, you're shortening the length of the torque wrench - you need to compensate for that when positioning your string because the initial measure is now off - should reposition the string at the original measurement of 11" which would require confirming with your measure tape (would shift slightly towards the end of the wrench a bit). small detail.
Well done Tom, I'd recommend everyone test their wrench at minimum, mid and maximum range. Let's face it, most of us won't have a bunch of torque wrenches where each has a range that overlaps the others in their kit by 50%, I know I can't afford that many. Whatever torque I need to apply, it will always only fit inside the range of one of my wrenches, that might be near the extremes of range. Excellent video, cheers.
Just thought of my first torque wrench, it had a pointer and a scale on it, the pointer was a thin rod in parallel to the main wrench bar; the challenge was to try and read where the pointer was while exerting steady pressure on the wrench! Geoff
Brilliant. I’ve got three torque wrenches I’ve had for years. Always take care of my tools but wondered if they had started to lie to me over time. Never even knew about the calibration bolt. Perhaps I should RTFM! Thanks & subscribed.
Brilliant - at last i have found someone calibrating a smaller 3/8 drive torque wrench in metric newtons rather than lbs! And plain and simply explaining the formula! Brilliant job - thanks a lot
Awesome explanation! One of the best I've came across! 👏 About the point where to hang the weight, actually that bit without knurling is there to be the exact center of the handle 😉
Checked all my torque wrenches with this procedure and was astonished how close high (priced) quality wrenches and cheap ones were. Many thanks for this excellent explanation....
Great video for the home DIYer. It is also important to remember that these torque wrenches are more applicable when you're working with multiple bolts that all need to be torqued the same. I.e. car wheel lugs, or a pump head flange, etc. For a single bolt, especially in a sensitive application, these torque wrenches only bring you within a ballpark spec and probably not the best tool to use. But this calibration method is simple, quick and yields acceptable results, so thanks very much for sharing.
Thanks for watching and sharing, it’s a great method to set and keep your torque wrenches accurate for what we use them for. It’s not perfect with the small variables, but it’s more than accurate enough and offers anyone the ability to maintain theirs without any money spent.
I forget my school knowledge aswell. Smily = My teacher hitnot my head at the table and told remeber these for a lot of years. BUT = always calibrate(with the force of the weight) where the manufacturer mark at the middle area where your hand push. You cant find a mark = Where your hand push , these area, in the middle. Yes = difficult but your calibration will be fine for your presicion you need. At the low value and the max torque value the inside spring is not perfect. Choose the torque between both extrem values. Or if you prefer a standart use value for your work = choose these value. Big problem = Find a weight (or some) and it must fit for your torque. You got a good precision libra for checking the weights ?
I found that the non-knurled ring is exactly the calibration point on three various wrenches. Checked by a weighed bucked of sand at home, then on a NIST-traceable calibrator at work.
Extremely well spoken and coherent video. You should be cloned and used to teach mathematics, physics, chemistry, and technical report writing throughout every single learning institution.
I prefer using a small luggage or fish scale, cheap to buy and accurate enough for this. Then just keep it at the measured distance on the wrench handle while pulling handle at 90 degree until it clicks...read max "weight" on the display. Adjust wrench calibration accordingly. This keeps the force at 90 degree to handle, no contribution from handle's own weight (as in this example with handle adding small amount to turning downward force applied). And no need for any calculations nor pre-weighed dead weights.
After you set the torque, you've moved the spot you measured to, so dont you have to re measure from the socket drive because the spot on the handle you choose is now half inch or so up the bar??????
Hey, yeah that’s right, I did as you said, but the video was made up of multiple segments and it should have been put in first. Set the handle adjustment, measure and then hang. Thanks for watching and commenting!
If I were doing this, I’d just choose one of those grooves in your handle and then always use that. Find a way to measure the “proof weight” and the length as accurately as you can. Still, at the end of the day, the mechanism is only so accurate. You may get it perfectly calibrated, but then repeat the same torque application ten times and still get 1-2% difference in applied torque. Also, it’ll probably be different along the range of torques. It’d be interesting to get a digital torque gauge and then measure a bunch of settings to see how the variation looked along the range. Also, if you use the setup like in the video, you’d need to account for the weight of the torque wrench in addition to the proof mass. 😜
are you kidding me? sipping beer and wondering if i should throw away this tool that i sheared not one, but TWO M6x1.0 bolts off,...and i find your video. THANK HEAVEN ABOVE!!!!! you not only taught me, you enlightened me. Thanks for this tutorial! you got another follower!
Thanks. We just looked at the calibration tag on all our torque wrenches. I worked in Maint. for a BIG airline. But I use them on my vehicles too. Great video.
I see 2 major flaws in your method, 1st: when you twist the handle to adjust the torque setting, the spot you've chosen to hang the weight has moved, now closer to the drive than you've measured before. To mitigate this, choose a torque and adjust wrench beforehand then calculate and measure where to hang the weights along the handle. 2nd: when it clicks, the torque wrench isn't perfectly parallel to the ground, it has sagged, hence the force of the weights acting on it isn't perfectly perpendicular. To mitigate this, let the wrench rest higher so when you put on the weights, it will click at approximately parallel to the ground.
Excellent and practical information. Just what I need for home use. When working in Nuclear We always warmed the T wrench up at the required setting at the test bench before and after the wrench was used. After this, the wrench went to the lab for recalibration. It's not overkill if it's for nuclear. Usefull tip. If you have lube on the flat contacting surface of the nut or bolt head. This will increase the torque significantly more than lube on the threads only.
This is extremely important to maintain the wrench. As an engineer, I performe this task every few months to maintain tooling. While i have load cells , I have used this method in the field using a car tire which was almost just as effective as the load cell.
This is awesome!! I never thought of looking for this process and always though that because I’m a diyer I’ll just assume that my torque wrenches will be within the tolerance. Thanks for this nice visual explanation!
I made a torque wrench 45 years ago special for ali engine motorcycles, I calibrated it by hanging a bucket by the handle and pouring in measured quantity of water.
The last torque wrench i bought was calibrated so i checked it against my others by using a hex socket and an Allen socket with one held in the vice. Worked quite well.
That's a good DIY method. It took me a while to get inch/pounds torque wrench set properly as it wasn't assembled right and had 'fallen apart' during shipping (it was a Stanly, sold for parts, surplus store had about 10 or more on display) At the time I had access to a Snap-On torque calibration - tester so accuracy was well within the +/- % specification. Vast majority of spring ('clicker') torque wrenches are only accurate at centre scale (+/- 2%) and are often 10% at maximum or minimum readings, even expensive ones.
Interesting however, to be more precise, don't forget to remove the weight of the torque wrench at the level of the grip (or to take it into account when calculating the weight), because when the torque wrench is horizontal, its own weight contributes to the torque and it distorts the calibration ... it's not essential on 1/2" torque wrenches but much more on 1/4" PS: sorry for my poor level in English
Good demonstration of a very practical method. Remember that the wrench itself held horizontally will itself exert torque from self weight, i.e. the mass of the handle through its center of gravity. Probably a minor correction.
Spot on, though I think you meant to say set vertically will exert force? It will marginally but very minimal. You can do it horizontally with luggage scales if you prefer :) thanks for watching and commenting!
Woow, thanks! I didnt knew that it was this easy. I have a nice quality torque wrench stuffed away due to huge inaccuracy (25-28%) I Will now try and calibrate it! 😃😍
Thanks thisbis great. I ended up with a snap on torque wrench from a guy who gave me a mixed bag of tools. Mostly cheap stuff but boy was i shocked when i pulled out a snap on torque wrench. Been wanting to check it out.
An OUTSTANDING presentation, VER. This also highlights the necessity to properly grip the handle when setting the torque on a fastener. If you pull from the end of the handle, it will not be torqued enough due to the leverage increase.
Thanks for the kind words :) technically it doesn’t make any difference to the bolt, the torque will be the same, it’s just the force you need to apply will change depending on where you’re holding it. It will all still be the same torque on the bolt :) it’s only when calibrating the torque wrench that you need the specific location on the handle as the weight applied is constant. Thanks again!
I have a Snap-on torque wrench that i turned in to be calibrated... The Snap-on tool man gave it back to me 3 weeks later and said it was too old to calibrate and the parts to calibrate it are discontinued. Then he laughed at me. I found out who made these torque wrenches for Snap-on and bought the 3 common wrenches for the cost of 1 Snap-on wrench! I still have the one i wanted calibrated, i think I'll try this method. Thanks🏆
I never knew we could calibrate a Torque wrench or that it needed to be calibrated, thank you, this is so simple to do and works really well, luckily my two Torque wrenches were spot on, they are only a couple years old as my old ones went to some one that borrowed them and I forgot who by the time I needed to use one :), a tip for anyone that lends their tools have a white board or chalk board on your wall rack to write on to remember who borrowed what as it can get quite expensive as the two replacement torque wrenches were about four times more expensive than I paid for my originals.
My 30 year old Sykes-Pickavant medium torque wrench was spot on (to within 1Nm). My cheap Clarke torque wrench, only used for car wheel nuts, was giving 10% less torque than indicated. You get what you pay for.
Nice. I did a Google search for a mark on the handle intended for CAL point, but found this. It's essentially the same but working backward and using an average distance to find the mid point (CAL point). Cheers Chris stop her.
Great explanation. One thing to point out is that the accuracy of this method is dependent on the accuracy of the measurement of the weight used. What sets the calibration of the scale?
For ft-lb it's easier to just use 1 foot from the point of rotation to hang your weight. No math required. Great video to demystify calibrating or checking torque wrenches 👍
Good video - but note that the place to hang the weight is right on the line in the middle of the knurled grip - that is the reference line and also where the pressure should be when using the wrench (have the middle of your hand on this line).
To calibrate a torque wrench, you have to verify the whole range, not just a point or two. You have to check the full scale, the minimum indication and several points in between. Then you may have to make a compromise to bring the whole scale in tolerance. You can't do it this way.The torque wrench you show is a cheap one. The precision of these wrenches is not even along the range, especially at the low end. I have such a cheap torque wrench and I calibrated it professionally (I work in a lab and I do calibrations for living). The range was 60-200 Nm, the first portion of 60-100 was useless( +20% error), but the rest 100-200Nm I was able to tune it bellow 1%.Therefore I use it only for torques above 100 Nm. My advice is to buy a $50-100 device. A relatively good quality torque wrench has specified in the manual, the length of the arm, so you can calculate the torque if you use an extension, If you're a mechanic you really don't need a $1000 torque wrench, you work in a shop not in a lab. Anyways, if you want to play with it, why not. There are professional calibration labs out there and they do it for a reasonable price and also you get a AALA recognized certificate of calibration.
If your torque wrench is set right on metric scale ,it will automatically be correct if you use it on the FT LB scale or any other scale it may have . The adjuster adjusts the same spring for all measurement scales on the torque wrench .
@@maskedavenger2578 yes but metric and imperial measurements don’t align in torque wrenches. If it’s a metric wrench, the imperial will be in decimal points on the other side. Not helpful.
@@VintageEngineRepairs If the wrench has imperial scale one side & metric on the other ,if one scale is accurate ,the other one will be also. They both set the same spring ,so the NM correct scale setting will be equal in tightness to the equivalent imperial scale setting . Otherwise torque wrench manufactures wouldn’t supply their wrenches with two scale types on one torque wrench ,as one wouldn’t be accurate .
Excellent! simply explained and clear verbal info! i have a New,out of the box 1/4 inch torque wrench that i need to check for accuracy to be sure, I will now also check my 3/8 and my 1/2 inch ones to reassure !! ty so much!!
I did the calculation to determine the Newton Meters added by the weight of my wrench handle. It’s a pretty cheap and standard 1/2 drive wrench, total handle length about 18”, and it weighs just under 3 lbs and I did all the calculations in metric units. The distance from the center of the drive to the groove in my handle is about 37.2 cm. When the wrench is held horizontally, the weight is distributed such that there is .661 Kg downward at the groove from which I would also hang the additional weights as necessary. Using VER’s formula, with no extra weight on the wrench, the weight of the wrench produces 2.42 NM. If the wrench clicks at 100 NM, the force of the weight of the wrench produces 2.42 NM and the weight is producing 97.58 NM. It would be easy enough to test at various weights and adjust the indication accordingly. That might be smart if you’re torquing bolts on the space shuttle. If you are torquing your snow tires, you are probably close enough without bothering to do the adjustment for the weight of the handle. Basic torque wrenches are usually calibrated to within +/- 4%. Thank you VER, this is a nice and useful video. 😊 PS: yes screwing in the dial does change the length (arm) in the calculation but I doubt it’s significant.
Thanks for doing the calculations! Much appreciated :) glad the video helped and thank you for the super thanks! It’s all much appreciated. Warm regards, Tom.
An Allen key??? Have to check - YES, my wrenches do have those. Always wondered how calibration works - and, yes, I am blushing. Greatly. Many thanks mate, sooo valuable info this.
I had a friend who would take his units out to the tool truck and compare against a new torque wrench. He used a hex key and a socket to mate them for the test. I have done that myself a few times and never had to do a calibration on my 3 units in 50 years.
wow bro this is so much useful i'm so thankful i pass thru this, imagine calibration center ask for a huge amount of bill for that and now i can do it for free 😁
@@VintageEngineRepairs knowing that you can indeed adjust them gives me more confidence to spend less on things I will use only occasionally and not for my main job.
@@VintageEngineRepairs Worse than expected So I checked the 5-25 first and it was actually ok, though the handle scale is completely useless. With rotating the handle from 0 to the next 0 (Half a turn) it would go up 2.5 numbers, so they're not to scale. Chinese muck, but the numbers on the shaft are close enough. Moving on the the 20-250 one I have that I was confident in, that was actually the one that was out. When inputting 50lbft into the shaft reading, it was only delivering 29lbft. I adjusted the screw until it was completely loose, and this only upped it to 38lbft. In the end, I removed the pin and circlip and pulled the top out, looked inside, seen nothing wrong and re-greased it and now it's within spec, the adjustment screw is at a comfortable position about halfway through its range, and it's delivering 48lbft when the scale reads 50. I think I'll be completely stripping it down, cleaning it and rebuilding it with new grease following that. This got the ball rolling at least. Can't believe all the bolts I've obviously under tightened over the years.
It's good to check that the wrench is not WILDLY out of adjustment. This is a good method. If by moving the rope only 5 mm up and down the handle changes the torque, one must then assume ANY force applied by the human hand over the distance of the knurled handle will produce merely an APPROXIMATION of a theoretical value. This is why some bolts etc. do not require "tension", but angles of required rotation. "Tension" is the screw thread (a helix, which is actually a coiled INCLINED PLANE or WEDGE) converting a "Moment"; Force x distance, to tensile load on a bolt imparted to that bolt by the thread.
@@VintageEngineRepairs I'm sorry if I am "preaching to the converted" . I've also changed my initial response to yr video. Cheers from the Hunter Valley.
From my understanding, the part of the handle without the knurling, is the exact spot where you’re supposed to hang something or push down on when calibrating.
it's important to ensure that the handle is as close as possible to horizontal, if you don't, not only will your weight probably slip, but the measurement will also be wrong! for any wondering, the 9.81 figure is G, the gravitational constant, aka how many Newtons of force does a Kilogram of mass apply. 1Kg of mass weighs 9.81N on earth. the 12 figure is just the conversion of inches to feet. if you multiply feet by lbs you get ftlbs, if you multiply inches by lbs you'd have to divide by an extra 12 to get ftlbs
If you don't have any weights and also want to measure different torques easily, take a digital body scale which you place on the floor so that you can comfortably operate the handle of the torque wrench. Then you stand on the scale and press the handle as you always use it. By measuring the difference between the displayed weight and your own body weight, you can easily check the function of the torque wrench.
I measure from a point 1ft from the square drive cos I use ft-lbs.....I use a fisherman's fish weighing tool....I have tested that its accurate. I have a few cheaper ebay type wrenches....I find all a few ft-lbs out....I check each time I use one....I dont use them very often.
There are some small errors. 1. You need to weigh the rope too. And dont forget: the handle has weight too. Doing the calibration many times might help average out the errors. 2. Using heavier weights might also help, because the percentage of the handle weight will be so small, that it basically can be ignored. Doing these measurements close to the minimum torque might cause the handle to have a bigger impact on the calibration. 3. and thats be biggest error: the moment your wrench clicks the handle isn't level anymore. The final force that makes your wrench click isn't orthogonal to the handle. You have to have the wrench pointed slightly upwards so that the click happens when the handle is perfectly level. Please correct me if I'm wrong. But i have to admit: if you're calibrating a 200nm torque wrench you propably don't need that accuracy. But things might be different if you use a smaller wrench for things like 6-10nm. If you need such a wrench, you need it to be precise.
Thanks for watching! The rope doesn’t need to be weighed. The handle makes a small difference, but can be omitted if you use fishing scales and work horizontally!
A metroligy lab would calibrate that wrench in 2 or 3 different spectrums of the scale. Lower end, middle, and upper end of the scale. If it is continously used at a specific setting, they may also include that in their calibration. Note any equipment used to set/measure the calibration must also be calibrated. In this case the tape measure and weight set. If the tool was found to be out of calibration, in this case +/- 4%, any item torqued with it after the previous calibration would need to be recalled. With that said, prior to calibration, the current torque should be measured prior to any adjustments. Also note that the bolt that was torqued also had a +/- tolerance and would be taked into the account of any recall. The frequency of calibration would be based on how often the the tool is used. Ben Retired 30 year 3M Quality Technician
So the string should be hung from the-smooth line on the knurled handle. Measure the distance from the middle of the square head drive to the string which follows moving the string an inch down or up the handle will change the effective torque setting. The best practical weight to use is equal to half the max torque wrench setting, otherwise pick weights to correspond to torque settings you use most often. I've heard that a click torque wrench is most accurate on the upper three quarters of the range and most accurate at maximum. I think most people over torque bolts because they use the wrong size. If you go below 20% of the max torque value(don't pay attention to the min torque values for the wrench if it is not 20% or more of max.) you might not get a good tactile response and over torque the fastener. So make those calculations before using or buying a wrench.
Hey, it makes no difference where it’s hung, it’s based off leverage and weight. You can hang it at the end of the handle or half way up, so long as you add the correct weight.
Example: "Condition need to meet to actually measure the exact Nm in KG" Lifting a 2kg weight can generate a force equivalent to 20Nm under specific conditions: 1. Gravity: 2kg weight exerts 19.6N force (on Earth's surface). 2. Lever or distance: Apply this force over a distance (e.g., lever arm) to get torque. Torque (Nm) = Force x Distance (m) Example: - 19.6N (force) x 1.02m (distance) ≈ 20Nm (torque) So, lifting a 2kg weight can generate approximately 20Nm torque if: - You lift it vertically (gravity applies). - You apply the force over a suitable distance (around 1.02 meters).
Great method! I think it should be underlined how accurately you should measure the distance. If you want to be even 4% accurate with the measurement, you cannot go "about 11 inch" or you'll be off by more than 4% for sure. It might be a good idea to use metal wire for hanging the weight to be sure you're applying it exactly correct position.
I have seen on those particular style torque wrench, absolutely do not take them past zero it screws them up immediately on there calibration, not a big fan of them , I do use them for cheap cheater bars works great for that Ive found, good video very informative on how to I like it
Maybe the manufacturer has resolved some of there issues with these things, but Ive owned 3 and 2 got turned below zero and they got very bad out of spec and the third was not even close to being there straight out the box..... So the snap torque wrenches have left me with trust issues , I always double check them after use with my old trusty needle style wrench, so far with the higher quality snap wrench I haven't had any issues with it yet, but I still don't put the 100% trust in it and always double check it
@@RonnieRose-f5x ah interesting to hear! I have only owned 2 and they’re good quality “enthusiast” quality I suppose. Not cheap home owner but not professional quality!
I tried both ways (i.e., testing and doing the math measuring the distance at the minimum setting and at a selected torque setting prior to adding the weight) and the first/original explanation seems more accurate. If you set the torque setting before measuring, the math equation simply doesn't work. In short, in my view, the original comment made in the video was and is correct. Either way, you have superb communication skills and a equally great demeanor. You'd be an excellent Professor.
Aviation regulations require clicker wrenches to be calibrated every 12 months to be legal to use on aircraft. Beam type wrenches do not ever need to be calibrated per FAA regulations.
Questions/comments: 1. You confirmed the weight of the sugar bag, dumbell etc …..using “a scale”. How do you know THAT measuring device is accurate? 2. You tested the torque wrench at ONE place. A proper calibration would test it all the way up and down the range it is used at. (It could test great at 20 ft-lbs, but be hopelessly off at 40 ft-lbs.
Hey! Lots of great questions, all I can say is that it has given me very accurate and consistent results for a long time. Whenever I compare it to another torque wrench it’s spot on and after all, it’s just used for small engine repair, it’s not used by NASA :)
One issue, the spring inside is not linear, I.E., it may register too low on a light weight setting and register too high on a heavy weight setting. I believe the best practical area to calibrate is around the center of the range, and preferably around the torque where you most intend the tool
You forgot to reposition your weight point after changing the setting on the wrench, if you change the setting, your weight point moves with the handle since the handle extends/retracts so you need to get your measuring tape back out and look where your weight position is now.
If this video helped you, please consider clicking on the THANKS button above to support my channel 🙌 PLEASE NOTE: there is an editing mistake in this video - ALWAYS set the specified torque by twisting the handle BEFORE measuring the length from the head. Otherwise your measurement will be wrong :) thanks!
The like button will have to do.
Thank you 😊
@@ClaudeSac Tbh hitting the thanks button wouldn't have occurred to me if he hadn't mentioned it - and I feel indebted for this invaluable and money-saving advice so it meant I could show my appreciation in some small way! With 5.7k likes, a small percentage of donations would really add up and encourage more advice like this. A few quid is a lot less than paying someone for the info, or recalibrating or replacing a tool!
Thank you! I appreciate the donation very much! Glad you enjoyed the video!!
Sir, your a genius and I can't thank you enough ❤❤❤❤
Nice tip, I will be re-calibrating both of my wrenches.
One tip I was given more years ago than I care to admit was to turn your torque wrench back to zero after use, relieving the tension on the spring.
Cheers, Geoff
Spot on Geoff! Always take the tension off :) thanks for watching and sharing 👍
At work, we had our torque wrenches calibrated yearly. As an experiment, I bought a really cheap one and left it wound right up for three years, it passed calibration.
@@paulhawkins6415 interesting! Thanks for sharing!
@@paulhawkins6415 "experts" say "don't keep your magazines loaded with ammo, as it will weaken the spring". Yet militaries around the world store full loaded magazines for who knows how long.
My magazine spring began to misfeed my H&K USP .45 in less than a year of being my always loaded bedside gun. Changed the spring, problem gone. @@savage22bolt32
You should measure the distance from the drive (where you hang your rope) AFTER you set the wrench to the appropriate weight because the handle moves in slightly toward the drive as you turn it. Also, make sure the wrench is perfectly level. Good tips, though. Thanks for sharing
Yep, thanks for watching. 👍
I could not believe nobody mentioned this, until I found your comment 😂👍🏼
These clicker type wrenches are typically calibrated for the force applied exactly at the middle of the grip (and it does matter, there are a few videos explaining and clearly demonstrating this), therefore that should be the point you hang your weights from and measure the distance to. Ideally, one should test different hanging positions on the handle with different weights at both ends of the wrench's torque range, find the position that gives the most accurate results throughout the torque range and then only apply force at that exact position during normal use. Whether it's going to be the middle of the handle or closer to either end of it really depends on each specific wrench model.
Yep! I have learnt something new here! Thanks for sharing :)
Also you need to take wrench handle weight into account. So actually it is way easier to calibrate it with torque meter.
A good post and usefull vid .👍
Most cheap high street wrenches are way off and need calibrating.
I Used to calibrate equipment as a tech support engineer both eletrical from fluke meters to torque wrenches Ultra light 6ft lbs too 500ft lb long bar.
Good advice for a rough home setting.
I'll just add to get it spot on you ideally need to check the lowest, the mid & the highest settings as the spring tension accuracy can vary hugely and may show that the tool is no longer accurate on all settings.
Most common reason is because people dont reset the wrench back to its lowest setting after use and just leave it for months with the internal spring under constant load.
Thanks for sharing your experience, great stuff :) yes, checking the full range is certainly worth doing!
tip, if you can go 12 inches on ft. lbs, you can set the wrench to the same as the weight you are hanging.. no math involved :)
Explain this a little further, not quite following, thanks
@rtg8point858 for the imperial the math is the weight ÷12 × the distance along the torque wrench.. if you go with 12 inches, the ÷ 12 × 12 nullifies itself, so the result is whatever weight you choose, that's what you set your torque wrench to.. no math involved at that point. Hope that explained it for you 😁👍🏻
@@JaneRoseDrummer Ok. That's what I thought you were saying, just wanted to be sure. Thanks
Yeah that's what a foot pound is, 1 pound at 1 foot
Good tip! You could also extend the handle with a pipe, or make your own tool to hang those weights at specific distances every time you do this. Ie. a two foot pipe with notches for the string at 12 and 18 inches, choose your weights according to the specs on the wrench. Super simple calibration every time. You also don´t need so much weight if you extend the leverage, so that might be a thing too.
this is gold ! perfectly shown an explained on NM and FT-LB in a simple way..... no useless blablabla simple perfect !
Thank you! I really appreciate it :)
How to calibrate a torque wrench..... and how to make a clear, well explained practical video. Great work.
Thank you :)
Great video. I'm going to try this out myself. One note: I think it is important for the torque wrench handle to be parallel to the ground. If it isn't parallel (or as nearly so as possible) then the effective length is different from the measured length thanks to vector trigonometry.
Yes sir you’re spot on! I think it’s important to be as accurate as we can, but also remember that even if things aren’t precision perfect - it will still be more than good enough for what we do :) you won’t snap bolts being a bit over nor will it cause an engine to fail being a bit under the specified torque. Thanks for sharing!
@@VintageEngineRepairs Just as a follow up, if you're within 10˚ of horizontal you'll be within 2% of accuracy, which is equivalent to +/- 4mm on your length measurement. Given your string is about 4mm in diameter, that's plenty of precision.
If you get out to 20˚ you're still within 7% of the calculated value, but it starts to rapidly fall off in accuracy after that.
😯
whoooeeew
math does hit hard 😭
@@daveatutubeAs the purpose is to calibrate the torque wrench, you want to do what you can to achieve max accuracy, and that does not involve having the handle at an angle.
@@VintageEngineRepairs You did not mention it, but did you weigh the rope with the weights? For that 1 or 2 % accuracy, the rope may make a difference. Not moaning, just checking/mentioning. Also, could we all say pound-foot, like Newton-meter? That's moaning ;)
This is the best DIY demo I've found. The process is not that complicated, although for accuracy the right angle distance and mass need to be accurate. I've often wondered how much ambient temperature affects this clicker style of wrench. In the end, most of the time a variance of 5% is fine. Often it is a comparative tool, so even if it is out a little, all the bolts will have the same torque. These days we tend to go overboard with torque, although the margin for error in aluminum housings can be small.
Thanks for watching :) I agree, for what we all do 5% even 10% is not a problem. Heck you could be even further out and not have any issues. If it was on a a spaceship then it’s a different ball game. This gets you very close, easy to do at home and will be far more accurate than doing it by hand :) thanks for watching!
I agree that this is a clever way for diy calibration. Although not complete. Even though the style of torque wrench you show here is common, there are a lot of different ones. And the method of adjustment also differs. Some do have the screw you show now, but also a lock screw for instance. A lot of professional wrenches also feature an adjustable scale.
Typically you adjust the screw you show in the video to set max torque, and adjust the scale for minium torque. Most cheaper wrenches have a fixed scale and I would recommend calibrating for the range you use, as it will be hard to get it right all along the scale.
Most professional torque wrenches are supposed to be within a 3% margin along the full scale. Typical calibration is done at 0% 60% and 100% force. It will be hard to get it to within this spec with this diy solution. But it's definitely better than not checking it at all. The 3% margin is also ludicrous if you ask me, how you hold the wrench, how you apply force, is your bolt dry or lubed, etc will have more effect on the end result the a bit bigger margin on your wrench.
Bear in mind that the electronic force gauges might also not be accurate. Especially cheap models can have quite some deviation. So you might want to check the force gauge with this method before using it to calibrate.
In short, good method for approximate calibration with little expense. But not suitable for critical work.
Just my 2 cents as someone in the tool business, including calibrations.
The wrench handle should be horizontal; maybe it's the camera angle that makes it look like it's pointed down, which would make it require a higher torque to click off.
nice easy instructions .. 79 years old mechanic learning every day .
Every days a school day :) thanks for watching!
the day we stop learning is the day we stop living😊
One thing not accounted for with this method is the weight of the handle, which is small but not zero. In the big picture it's likely negligible. I suppose one could measure this with a simple experiment. Suspend the wrench with a string looped around the center of the head, then support the handle end with a scale. Multiply the measured scale weight by the right angle distance from scale contact point to string, and you've got baseline torque with no extra weight added.
Yeah I agree with you, it’s negligible, as mentioned before, for what we do, it’s not going to make a difference. Most torque wrenches come with, from memory, +/- 10% accuracy. Thanks for watching and commenting, it’s always good to hear other people’s opinions and ideas :)
To eliminate the weight effect, you could turn the torque wrench sideways and apply a known force from a fish scale.
Ah, but then you'd have to add or subtract the weight of the handle depending on whether you're pushing it up or pulling it down when you're actually using it. If the bolt is vertical and the handle is rotating horizontally then no correction would be needed.
Put the wrench in the vise horizontally and run the cord over a pulley or some other low friction device to turn its path from horizontal to vertical
@@michaelallen5505that's not true, you would be applying however much force is needed to reach the torque spec regardless
Very cool, Tom! I knew a specific torque was dependant on weight and distance, so your procedure is brilliant. Those two figures and the conversions are all that's needed. Way to go!
Thank you! I’m glad you enjoyed the video and found it helpful!
When I was taught to use a torque wrench many year ago. We were told that the break in the knurling or the thin band of knurling was where your middle finger was supposed to be placed. The reason given was that this represented the calibrated distance from the drive head to achieve the most accurate torque. After watching your video, that make sense and would cause me to use the as a reference when calibrating. Either way, I really liked the video and thanks for the cool trick to add to my knowledge.
Thanks for sharing and the kind words h
I don't think it matters where you hold it, the wrench still has the same accuracy just the force you need to apply will differ slightly but it will still click at the same nut torque force
@@stargazer7644 I use my digital torque wrench as a torque meter to test my other torque wrenches.
@@stargazer7644 It does matter where you hold and calibrate the torque wrench. You are meant to apply the force at the groove that all of these torque wrenches have. They all have them for a reason. I know that may be unexpected because a torque is a torque after all, but these click-style torque wrenches complicate things somewhat.
There are actually two torques in play here: one torque at the head of the torque wrench which is wrenching on some fastener, which is what we want to measure, and another torque at the "elbow" between the head and the handle. The torque wrench actually measure the torque at the elbow, which is where the clicker is, and we use that to stand in for the torque at the head. That works fine if we calibrate things right to give us the right numbers.
However, the calibration assumes a particular ratio between the handle length and head length.
To gain an intuition for this, imagine a particular torque wrench that has a particular torque dialed in. In your imagination, apply a torque at the groove and make the wrench click. Now, leaving everything else exactly the same, modify the wrench to lengthen the head and shorten the handle, but let's leave the total length the same as before. Let's say the handle is now half as long as it was, which means that the elbow will now be approximately half way along the wrench. Now, apply the same torque as before. Will it click? No, it won't because the lever arm to the elbow is half as long as it was before. You will have to apply twice the force to make it click now.
That shows that the ratio between the two lengths does matter. Going back to the original torque wrench now, if you apply the force at a different place, you will be changing the ratio.
@@stargazer7644 The force from your hand should be applied at the same point that the calibration force was applied. You might as well use the groove that is put there for that purpose in every single click-style torque wrench.
I know what you are saying. A torque is a torque. But that doesn't apply to click-style torque wrenches, as I explained above, because the "elbow" point, where the clicker is, is not at the same place as the "socket" point.
The actual measurement point (the "elbow") is not exactly at the same place as the intended torque application point (the "socket").
For other styles of torque wrench such as a digital one or a deflecting beam one, then yes, it wouldn't matter where you hold it because the measurement point (the transducer in the digital one for instance) is at exactly the same place as the socket.
Minimum spec on my Torque Wrench was 20 FT Pounds. I didn't do much math and still calibrated it. I though to myself "Foot, pound" Therefor 1 Foot away from the head should required 20pounds of load is what is needed to click it at the 20Foot Pound setting. So i filled up a bucket with 20 pounds worth of water and i was able to perfectly calibrate it. *I was able to verify this theorie with a new one and it clicked right when i was laying down the handle of the bucket on it.
Sweet as, good work :)
I dont want to explain the reason, but ...
... always calibrate with the force of the weight where the manufacturer marked ist at the handle.
(If you can find a mark = It is the middle of the area where your hand will be !)
(You see it here in the video)
If you choose an other point of the force from the weight = Calibration is wrong.
Additional information = Please no discussion !
There is a reason why simply choose a nice distance from the middle of the squere Socket adapter to a nice distance for an easy calculation ...
... will result a wrong calibration !
See other videos that explain the reason (=it is inside and we cant see it and our brain always refuse these reason. But it is true = middle of the grip zone where your hand will be (often good manufacturer mark these area).
Discussion with these RUclips channels (or a maufacturer or these mechanical torque wrench with the easy inside construction.
Remember there are Split beam torque wrench (= I never ask one of these manufacturer or saw a calibration RUclipsvideo that explain these physical rules for calibration. But I bet force of the weight at the middle of the handle).
@@callishandy8133 The breakout point being well short of the drive, is the first clue that you are absolutely correct!
Great video and so simple to do. I have been told by multiple tool shops that the smooth ring in the handle is the factory point where they test the torque wrench. Not sure if it is true but you might as well use it as a fixed point for future calibrations so you get the same point each time. You'll also notice that the ring is slightly closer the end of the grip, this is because when we pull on a handle at 90 degrees more of the force is concentrated towards the last 3 fingers (middle, ring and pinky) on our hand. This enables us to grip something very tightly while still being able to use our thumb and fore finger for other things. Try it out.
Thanks for sharing, much appreciated :) I’ll give it a go!
Yes, I noticed on your last click test by hand you probably without thinking positioned your hand right over where that band is on the handle. Cheers, great video
@@nigelthompson874 well spotted :)
Yes, typically the handle is marked for this purpose. Not just for factory calibration, but also for recalibration. Different brands use different marks, but I would expect the clear ring to be the mark in this case.
Thanks for this, I have been wanting to calibrate my 1/2 inch torque wrench for years, but never thought about a method like this.
Awesome! It’s really simple :) glad you enjoyed it!
when you turn the setting handle, you're shortening the length of the torque wrench - you need to compensate for that when positioning your string because the initial measure is now off - should reposition the string at the original measurement of 11" which would require confirming with your measure tape (would shift slightly towards the end of the wrench a bit). small detail.
Spot on! Yes I got the edit backwards, but you’re right! Measure after setting the torque :) thanks for sharing!
@@VintageEngineRepairs no worries - thanks for making such a good video on a somewhat 'mystery' topic most home mechanics would benefit from watching
Thank you for the kind words and correction :)
Well done Tom, I'd recommend everyone test their wrench at minimum, mid and maximum range. Let's face it, most of us won't have a bunch of torque wrenches where each has a range that overlaps the others in their kit by 50%, I know I can't afford that many. Whatever torque I need to apply, it will always only fit inside the range of one of my wrenches, that might be near the extremes of range. Excellent video, cheers.
Thanks for sharing and I agree! Glad you enjoyed the video :)
I used this method and my very old wrench was off by only a few pounds (maybe 5). I made the adjustment, and the whole process was very easy. Thanks.
Super pleased you put it into practise and had the expected success :) well done!
Just thought of my first torque wrench, it had a pointer and a scale on it, the pointer was a thin rod in parallel to the main wrench bar; the challenge was to try and read where the pointer was while exerting steady pressure on the wrench!
Geoff
Ah yes, a beam type torque wrench?
Brilliant. I’ve got three torque wrenches I’ve had for years. Always take care of my tools but wondered if they had started to lie to me over time. Never even knew about the calibration bolt. Perhaps I should RTFM! Thanks & subscribed.
Glad you enjoyed the video! Hope it helps calibrate yours :)
Brilliant - at last i have found someone calibrating a smaller 3/8 drive torque wrench in metric newtons rather than lbs!
And plain and simply explaining the formula!
Brilliant job - thanks a lot
Thanks! Glad you enjoyed it!
Awesome explanation!
One of the best I've came across! 👏
About the point where to hang the weight, actually that bit without knurling is there to be the exact center of the handle 😉
Awesome! Glad you enjoyed it :) thanks for sharing too 👍
Checked all my torque wrenches with this procedure and was astonished how close high (priced) quality wrenches and cheap ones were. Many thanks for this excellent explanation....
Glad you enjoyed it and found it helpful!
Great video for the home DIYer. It is also important to remember that these torque wrenches are more applicable when you're working with multiple bolts that all need to be torqued the same. I.e. car wheel lugs, or a pump head flange, etc. For a single bolt, especially in a sensitive application, these torque wrenches only bring you within a ballpark spec and probably not the best tool to use. But this calibration method is simple, quick and yields acceptable results, so thanks very much for sharing.
Thanks for watching and sharing, it’s a great method to set and keep your torque wrenches accurate for what we use them for. It’s not perfect with the small variables, but it’s more than accurate enough and offers anyone the ability to maintain theirs without any money spent.
Didn't realize these were so easily adjustable. Good to know, thanks!
You’re welcome! :)
I forget my school knowledge aswell.
Smily = My teacher hitnot my head at the table and told remeber these for a lot of years.
BUT = always calibrate(with the force of the weight) where the manufacturer mark at the middle area where your hand push.
You cant find a mark = Where your hand push , these area, in the middle.
Yes = difficult
but your calibration will be fine for your presicion you need.
At the low value and the max torque value the inside spring is not perfect. Choose the torque between both extrem values.
Or if you prefer a standart use value for your work = choose these value.
Big problem = Find a weight (or some)
and it must fit for your torque.
You got a good precision libra for checking the weights ?
I found that the non-knurled ring is exactly the calibration point on three various wrenches. Checked by a weighed bucked of sand at home, then on a NIST-traceable calibrator at work.
Thank you for sharing!! Much appreciated :)
I've always assumed that was what the ring was for - It's around the centre of effort when holding the handle. - Nice to have it confirmed.👍
I literally cannot “like” this instructional enough….this…this right here, is what I needed to see! Thanks man! You are a savior of my OCD…..
Haha that’s awesome, glad you enjoyed it!
always back off torque wrench when finished using relieving spring pressure
Spot on, couldn’t agree more!
Agree...
Wrong, leave a small amount of pressure, 5 ft lbs, so the spring isn't collapsed on itself.
I see leave 5 and zero...ok, lock it or keep unlocked
@@jeremywallace5961how does a spring collapse in on itself?
Extremely well spoken and coherent video. You should be cloned and used to teach mathematics, physics, chemistry, and technical report writing throughout every single learning institution.
Wow that is kind, thank you!!
I prefer using a small luggage or fish scale, cheap to buy and accurate enough for this. Then just keep it at the measured distance on the wrench handle while pulling handle at 90 degree until it clicks...read max "weight" on the display. Adjust wrench calibration accordingly. This keeps the force at 90 degree to handle, no contribution from handle's own weight (as in this example with handle adding small amount to turning downward force applied). And no need for any calculations nor pre-weighed dead weights.
That’s a great idea if you have the scale, yes! I don’t have that but it would be handy! Thanks for sharing :)
Thank you. I'm just a home mechanic/tinkerer so have never had my torque wrenches calibrated. Now I can do it myself! Thank you!
You’re very welcome :)
After you set the torque, you've moved the spot you measured to, so dont you have to re measure from the socket drive because the spot on the handle you choose is now half inch or so up the bar??????
Hey, yeah that’s right, I did as you said, but the video was made up of multiple segments and it should have been put in first. Set the handle adjustment, measure and then hang. Thanks for watching and commenting!
@@VintageEngineRepairsThis info should be pinned comment!😉
Brilliant thank you
Exactly what I was questioning!
If I were doing this, I’d just choose one of those grooves in your handle and then always use that. Find a way to measure the “proof weight” and the length as accurately as you can. Still, at the end of the day, the mechanism is only so accurate. You may get it perfectly calibrated, but then repeat the same torque application ten times and still get 1-2% difference in applied torque. Also, it’ll probably be different along the range of torques. It’d be interesting to get a digital torque gauge and then measure a bunch of settings to see how the variation looked along the range. Also, if you use the setup like in the video, you’d need to account for the weight of the torque wrench in addition to the proof mass. 😜
Not sure how I got this recomended but you are a legend mate, one of the simplest and well explained videos I've seen on the matter
Thank you!
Great Vid Tom, I would just add at 0:45 that the 9.81 is Newtons/Kg so that the units would cancel out and leave you with Newton Meters. Good Stuff!
Thanks Kenny! Much appreciated mate 👍👍
are you kidding me? sipping beer and wondering if i should throw away this tool that i sheared not one, but TWO M6x1.0 bolts off,...and i find your video. THANK HEAVEN ABOVE!!!!! you not only taught me, you enlightened me. Thanks for this tutorial! you got another follower!
Haha that’s awesome :) glad you find it helpful!
Kudos Tom. Liked & Subscribed: Clearly explained and demonstrated. From 'across the pond' John 14:6
Thanks Rodger mate :) much appreciated! I’m glad you enjoyed it!
Thanks. We just looked at the calibration tag on all our torque wrenches.
I worked in Maint. for a BIG airline.
But I use them on my vehicles too.
Great video.
Ah awesome! Thanks for sharing :)
I see 2 major flaws in your method, 1st: when you twist the handle to adjust the torque setting, the spot you've chosen to hang the weight has moved, now closer to the drive than you've measured before. To mitigate this, choose a torque and adjust wrench beforehand then calculate and measure where to hang the weights along the handle. 2nd: when it clicks, the torque wrench isn't perfectly parallel to the ground, it has sagged, hence the force of the weights acting on it isn't perfectly perpendicular. To mitigate this, let the wrench rest higher so when you put on the weights, it will click at approximately parallel to the ground.
Yep spot on, it was an editing error, I left a pinned comment covering this! I now do this horizontally with luggage scales :)
Should I factor in the weight of the torque wrench too?
I really was overthinking this process. It's as straightforward as it seemed when I first thought about how to do it!
Awesome glad you enjoyed it :)
Why not hang the weight on it and then turn the screw until it clicks. Then you know you're dead nuts the first time.
You put a lot of tension on the spring loading and twisting, but I do like that idea! Just not sure it’s going to be quicker.
What a great demonstration! I had no idea that you could do this, but it make perfect sense!
Glad you enjoyed it!
Fifth are we being silly 🥹
🤣
Excellent and practical information. Just what I need for home use. When working in Nuclear
We always warmed the T wrench up at the required setting at the test bench before and after the wrench was used. After this, the wrench went to the lab for recalibration. It's not overkill if it's for nuclear. Usefull tip. If you have lube on the flat contacting surface of the nut or bolt head. This will increase the torque significantly more than lube on the threads only.
Thanks for the kind words :) yep spot on, read the manual each time to see if the torque spec specifies dry of lubed bolt!
This is extremely important to maintain the wrench. As an engineer, I performe this task every few months to maintain tooling. While i have load cells , I have used this method in the field using a car tire which was almost just as effective as the load cell.
Awesome! Thanks for sharing :)
This is awesome!! I never thought of looking for this process and always though that because I’m a diyer I’ll just assume that my torque wrenches will be within the tolerance. Thanks for this nice visual explanation!
Awesome! Glad you enjoyed it :)
I made a torque wrench 45 years ago special for ali engine motorcycles, I calibrated it by hanging a bucket by the handle and pouring in measured quantity of water.
Nice :)
Thank you so much for this, I've been suspicious of the torque settings on my wrench for ages and this really helped me sort it out.
You’re welcome :)
The last torque wrench i bought was calibrated so i checked it against my others by using a hex socket and an Allen socket with one held in the vice. Worked quite well.
Awesome! :)
Can you try it with the method shown in the video?
I have a couple of torque wrenches that I've had for years and never had them calibrated, good to know it's an easy process to do myself. Thanks!
You’re welcome :)
That's a good DIY method.
It took me a while to get inch/pounds torque wrench set properly as it wasn't assembled right and had 'fallen apart' during shipping (it was a Stanly, sold for parts, surplus store had about 10 or more on display)
At the time I had access to a Snap-On torque calibration - tester so accuracy was well within the +/- % specification.
Vast majority of spring ('clicker') torque wrenches are only accurate at centre scale (+/- 2%) and are often 10% at maximum or minimum readings, even expensive ones.
Yep I couldn’t agree more with your last paragraph and I’m glad you enjoyed this video!
Thanks Brother. I have been using 2 wrenches together and " Clicking" from there. This is way more accurate.
THANKS Tom
Awesome mate ;) glad it helped!
Unless you know your first wrench is calibrated properly, you don't know if it's accurate.
Interesting however, to be more precise, don't forget to remove the weight of the torque wrench at the level of the grip (or to take it into account when calculating the weight), because when the torque wrench is horizontal, its own weight contributes to the torque and it distorts the calibration ... it's not essential on 1/2" torque wrenches but much more on 1/4"
PS: sorry for my poor level in English
Thanks for sharing 👍
Good demonstration of a very practical method. Remember that the wrench itself held horizontally will itself exert torque from self weight, i.e. the mass of the handle through its center of gravity. Probably a minor correction.
Spot on, though I think you meant to say set vertically will exert force? It will marginally but very minimal. You can do it horizontally with luggage scales if you prefer :) thanks for watching and commenting!
Woow, thanks! I didnt knew that it was this easy.
I have a nice quality torque wrench stuffed away due to huge inaccuracy (25-28%)
I Will now try and calibrate it! 😃😍
Awesome! Glad you enjoyed it!
Thanks thisbis great. I ended up with a snap on torque wrench from a guy who gave me a mixed bag of tools. Mostly cheap stuff but boy was i shocked when i pulled out a snap on torque wrench. Been wanting to check it out.
That’s awesome, great score!!
An OUTSTANDING presentation, VER. This also highlights the necessity to properly grip the handle when setting the torque on a fastener. If you pull from the end of the handle, it will not be torqued enough due to the leverage increase.
Thanks for the kind words :) technically it doesn’t make any difference to the bolt, the torque will be the same, it’s just the force you need to apply will change depending on where you’re holding it. It will all still be the same torque on the bolt :) it’s only when calibrating the torque wrench that you need the specific location on the handle as the weight applied is constant. Thanks again!
I have a Snap-on torque wrench that i turned in to be calibrated... The Snap-on tool man gave it back to me 3 weeks later and said it was too old to calibrate and the parts to calibrate it are discontinued. Then he laughed at me. I found out who made these torque wrenches for Snap-on and bought the 3 common wrenches for the cost of 1 Snap-on wrench! I still have the one i wanted calibrated, i think I'll try this method. Thanks🏆
Glad you got it sorted :) thanks for watching!
@@VintageEngineRepairs i just looked at my torque wrench and there's no calibration screw like you have
I never knew we could calibrate a Torque wrench or that it needed to be calibrated, thank you, this is so simple to do and works really well, luckily my two Torque wrenches were spot on, they are only a couple years old as my old ones went to some one that borrowed them and I forgot who by the time I needed to use one :), a tip for anyone that lends their tools have a white board or chalk board on your wall rack to write on to remember who borrowed what as it can get quite expensive as the two replacement torque wrenches were about four times more expensive than I paid for my originals.
Glad it helped!!
Excellent video. Very accurate, simple, and no fancy tools required!
Thank you!
My 30 year old Sykes-Pickavant medium torque wrench was spot on (to within 1Nm). My cheap Clarke torque wrench, only used for car wheel nuts, was giving 10% less torque than indicated. You get what you pay for.
Thanks for sharing!
Did this years ago. Can also use a wrench clamped to something like a work bench instead of a vice or horizontal bolt.
Absolutely :) thanks for watching!
Nice. I did a Google search for a mark on the handle intended for CAL point, but found this. It's essentially the same but working backward and using an average distance to find the mid point (CAL point). Cheers Chris stop her.
Interesting! Thanks for sharing :)
Great explanation. One thing to point out is that the accuracy of this method is dependent on the accuracy of the measurement of the weight used. What sets the calibration of the scale?
Hey thanks for the kind words, it’s accurate enough for my needs haha
Clear and concise Tom, thank you mate
You’re very welcome mate, thanks for watching! :)
For ft-lb it's easier to just use 1 foot from the point of rotation to hang your weight. No math required. Great video to demystify calibrating or checking torque wrenches 👍
Thanks for sharing :)
Could you simplify on how to do this? Sorry, I'm drawing a complete blank at the moment lol
Is your torque wrench in foot pounds or Newton meters?
@@VintageEngineRepairs foot pounds
How do you tackle dual unit wrenches?
Good video - but note that the place to hang the weight is right on the line in the middle of the knurled grip - that is the reference line and also where the pressure should be when using the wrench (have the middle of your hand on this line).
Thanks for sharing! Much appreciated :)
To calibrate a torque wrench, you have to verify the whole range, not just a point or two. You have to check the full scale, the minimum indication and several points in between. Then you may have to make a compromise to bring the whole scale in tolerance. You can't do it this way.The torque wrench you show is a cheap one. The precision of these wrenches is not even along the range, especially at the low end. I have such a cheap torque wrench and I calibrated it professionally (I work in a lab and I do calibrations for living). The range was 60-200 Nm, the first portion of 60-100 was useless( +20% error), but the rest 100-200Nm I was able to tune it bellow 1%.Therefore I use it only for torques above 100 Nm. My advice is to buy a $50-100 device. A relatively good quality torque wrench has specified in the manual, the length of the arm, so you can calculate the torque if you use an extension, If you're a mechanic you really don't need a $1000 torque wrench, you work in a shop not in a lab. Anyways, if you want to play with it, why not. There are professional calibration labs out there and they do it for a reasonable price and also you get a AALA recognized certificate of calibration.
Thanks for watching 👍
Thank you! Finally a clear, precise video on how to calibrate the torque wrench in Nm! I won't have to convert inches and pounds. Thank you good sir!
You’re very welcome!
If your torque wrench is set right on metric scale ,it will automatically be correct if you use it on the FT LB scale or any other scale it may have . The adjuster adjusts the same spring for all measurement scales on the torque wrench .
@@maskedavenger2578 yes but metric and imperial measurements don’t align in torque wrenches. If it’s a metric wrench, the imperial will be in decimal points on the other side. Not helpful.
@@VintageEngineRepairs If the wrench has imperial scale one side & metric on the other ,if one scale is accurate ,the other one will be also. They both set the same spring ,so the NM correct scale setting will be equal in tightness to the equivalent imperial scale setting . Otherwise torque wrench manufactures wouldn’t supply their wrenches with two scale types on one torque wrench ,as one wouldn’t be accurate .
@@maskedavenger2578Look at your torque wrench and you’ll understand what I’m referring to.
Excellent! simply explained and clear verbal info! i have a New,out of the box 1/4 inch torque wrench that i need to check for accuracy to be sure, I will now also check my 3/8 and my 1/2 inch ones to reassure !! ty so much!!
Awesome! You’re very welcome :)
I did the calculation to determine the Newton Meters added by the weight of my wrench handle.
It’s a pretty cheap and standard 1/2 drive wrench, total handle length about 18”, and it weighs just under 3 lbs and I did all the calculations in metric units. The distance from the center of the drive to the groove in my handle is about 37.2 cm. When the wrench is held horizontally, the weight is distributed such that there is .661 Kg downward at the groove from which I would also hang the additional weights as necessary. Using VER’s formula, with no extra weight on the wrench, the weight of the wrench produces 2.42 NM.
If the wrench clicks at 100 NM, the force of the weight of the wrench produces 2.42 NM and the weight is producing 97.58 NM. It would be easy enough to test at various weights and adjust the indication accordingly. That might be smart if you’re torquing bolts on the space shuttle. If you are torquing your snow tires, you are probably close enough without bothering to do the adjustment for the weight of the handle. Basic torque wrenches are usually calibrated to within +/- 4%.
Thank you VER, this is a nice and useful video. 😊
PS: yes screwing in the dial does change the length (arm) in the calculation but I doubt it’s significant.
Thanks for doing the calculations! Much appreciated :) glad the video helped and thank you for the super thanks! It’s all much appreciated. Warm regards, Tom.
An Allen key??? Have to check - YES, my wrenches do have those. Always wondered how calibration works - and, yes, I am blushing. Greatly. Many thanks mate, sooo valuable info this.
Glad you enjoyed it, yes Allen key or hex key, same thing :)
@@VintageEngineRepairs 😁
I'm off to my shed, with a couple of weights. Excellent explanation. Thanks.
Awesome :) enjoy!!
I had a friend who would take his units out to the tool truck and compare against a new torque wrench. He used a hex key and a socket to mate them for the test. I have done that myself a few times and never had to do a calibration on my 3 units in 50 years.
That’s interesting, thanks for sharing!
wow bro this is so much useful i'm so thankful i pass thru this,
imagine calibration center ask for a huge amount of bill for that and now i can do it for free 😁
Glad you enjoyed it and found it helpful!! :)
You earned my like. I was wondering how good a cheap torque wrench would be and found this video.
Thank you!
@@VintageEngineRepairs knowing that you can indeed adjust them gives me more confidence to spend less on things I will use only occasionally and not for my main job.
Excellent video and one I'm sure to review many times in the future. If there was one thing that could be improved, it would be the sound quality.
Thanks for sharing and the feedback!
Thanks for this. I have confidence in my 20-250 torque wrench, but I have a smaller 2-25 one I'm sure is overtorquing. Out to the shed I go!
Sweet :) how did you go?!
@@VintageEngineRepairs Worse than expected
So I checked the 5-25 first and it was actually ok, though the handle scale is completely useless. With rotating the handle from 0 to the next 0 (Half a turn) it would go up 2.5 numbers, so they're not to scale. Chinese muck, but the numbers on the shaft are close enough.
Moving on the the 20-250 one I have that I was confident in, that was actually the one that was out. When inputting 50lbft into the shaft reading, it was only delivering 29lbft. I adjusted the screw until it was completely loose, and this only upped it to 38lbft. In the end, I removed the pin and circlip and pulled the top out, looked inside, seen nothing wrong and re-greased it and now it's within spec, the adjustment screw is at a comfortable position about halfway through its range, and it's delivering 48lbft when the scale reads 50.
I think I'll be completely stripping it down, cleaning it and rebuilding it with new grease following that. This got the ball rolling at least. Can't believe all the bolts I've obviously under tightened over the years.
It's good to check that the wrench is not WILDLY out of adjustment. This is a good method.
If by moving the rope only 5 mm up and down the handle changes the torque, one must then assume ANY force applied by the human hand over the distance of the knurled handle will produce merely an APPROXIMATION of a theoretical value. This is why some bolts etc. do not require "tension", but angles of required rotation. "Tension" is the screw thread (a helix, which is actually a coiled INCLINED PLANE or WEDGE) converting a "Moment"; Force x distance, to tensile load on a bolt imparted to that bolt by the thread.
Thanks for sharing 👍
@@VintageEngineRepairs I'm sorry if I am "preaching to the converted" . I've also changed my initial response to yr video. Cheers from the Hunter Valley.
That's why the grip has a pivot axle. As long as the grip "floats" and is not allowed to contact the wrench, all force is applied at the pivot axle.
From my understanding, the part of the handle without the knurling, is the exact spot where you’re supposed to hang something or push down on when calibrating.
I have heard others say that too, thanks for watching!
it's important to ensure that the handle is as close as possible to horizontal, if you don't, not only will your weight probably slip, but the measurement will also be wrong!
for any wondering, the 9.81 figure is G, the gravitational constant, aka how many Newtons of force does a Kilogram of mass apply. 1Kg of mass weighs 9.81N on earth.
the 12 figure is just the conversion of inches to feet. if you multiply feet by lbs you get ftlbs, if you multiply inches by lbs you'd have to divide by an extra 12 to get ftlbs
Thanks for sharing 👍👍
This is the best video ive stumbled upon all year thanks!
Awesome! You’re very welcome :)
If you don't have any weights and also want to measure different torques easily, take a digital body scale which you place on the floor so that you can comfortably operate the handle of the torque wrench. Then you stand on the scale and press the handle as you always use it. By measuring the difference between the displayed weight and your own body weight, you can easily check the function of the torque wrench.
Thanks for sharing an alternative method!
I measure from a point 1ft from the square drive cos I use ft-lbs.....I use a fisherman's fish weighing tool....I have tested that its accurate.
I have a few cheaper ebay type wrenches....I find all a few ft-lbs out....I check each time I use one....I dont use them very often.
Nice :) sounds like you have a method that is quick and works well for you!
There are some small errors.
1. You need to weigh the rope too. And dont forget: the handle has weight too. Doing the calibration many times might help average out the errors.
2. Using heavier weights might also help, because the percentage of the handle weight will be so small, that it basically can be ignored. Doing these measurements close to the minimum torque might cause the handle to have a bigger impact on the calibration.
3. and thats be biggest error: the moment your wrench clicks the handle isn't level anymore. The final force that makes your wrench click isn't orthogonal to the handle.
You have to have the wrench pointed slightly upwards so that the click happens when the handle is perfectly level.
Please correct me if I'm wrong.
But i have to admit: if you're calibrating a 200nm torque wrench you propably don't need that accuracy. But things might be different if you use a smaller wrench for things like 6-10nm. If you need such a wrench, you need it to be precise.
Thanks for watching! The rope doesn’t need to be weighed. The handle makes a small difference, but can be omitted if you use fishing scales and work horizontally!
Thank you 😊
You are very clear and easy to follow.
Very much appreciated 👍
Ted.
You’re welcome! :)
A metroligy lab would calibrate that wrench in 2 or 3 different spectrums of the scale. Lower end, middle, and upper end of the scale. If it is continously used at a specific setting, they may also include that in their calibration.
Note any equipment used to set/measure the calibration must also be calibrated. In this case the tape measure and weight set.
If the tool was found to be out of calibration, in this case +/- 4%, any item torqued with it after the previous calibration would need to be recalled. With that said, prior to calibration, the current torque should be measured prior to any adjustments. Also note that the bolt that was torqued also had a +/- tolerance and would be taked into the account of any recall.
The frequency of calibration would be based on how often the the tool is used.
Ben
Retired 30 year 3M Quality Technician
Thanks for watching 👍
So the string should be hung from the-smooth line on the knurled handle. Measure the distance from the middle of the square head drive to the string which follows moving the string an inch down or up the handle will change the effective torque setting. The best practical weight to use is equal to half the max torque wrench setting, otherwise pick weights to correspond to torque settings you use most often. I've heard that a click torque wrench is most accurate on the upper three quarters of the range and most accurate at maximum. I think most people over torque bolts because they use the wrong size. If you go below 20% of the max torque value(don't pay attention to the min torque values for the wrench if it is not 20% or more of max.) you might not get a good tactile response and over torque the fastener. So make those calculations before using or buying a wrench.
Hey, it makes no difference where it’s hung, it’s based off leverage and weight. You can hang it at the end of the handle or half way up, so long as you add the correct weight.
Example: "Condition need to meet to actually measure the exact Nm in KG"
Lifting a 2kg weight can generate a force equivalent to 20Nm under specific conditions:
1. Gravity: 2kg weight exerts 19.6N force (on Earth's surface).
2. Lever or distance: Apply this force over a distance (e.g., lever arm) to get torque.
Torque (Nm) = Force x Distance (m)
Example:
- 19.6N (force) x 1.02m (distance) ≈ 20Nm (torque)
So, lifting a 2kg weight can generate approximately 20Nm torque if:
- You lift it vertically (gravity applies).
- You apply the force over a suitable distance (around 1.02 meters).
Thanks for watching and sharing
Great method! I think it should be underlined how accurately you should measure the distance. If you want to be even 4% accurate with the measurement, you cannot go "about 11 inch" or you'll be off by more than 4% for sure. It might be a good idea to use metal wire for hanging the weight to be sure you're applying it exactly correct position.
Good advise :) thanks for sharing!
Fantastic ,simple, straight forward . Thanks
You’re welcome :)
I have seen on those particular style torque wrench, absolutely do not take them past zero it screws them up immediately on there calibration, not a big fan of them , I do use them for cheap cheater bars works great for that Ive found, good video very informative on how to I like it
Interesting I have gone below zero without issue.
Maybe the manufacturer has resolved some of there issues with these things, but Ive owned 3 and 2 got turned below zero and they got very bad out of spec and the third was not even close to being there straight out the box..... So the snap torque wrenches have left me with trust issues , I always double check them after use with my old trusty needle style wrench, so far with the higher quality snap wrench I haven't had any issues with it yet, but I still don't put the 100% trust in it and always double check it
@@RonnieRose-f5x ah interesting to hear! I have only owned 2 and they’re good quality “enthusiast” quality I suppose. Not cheap home owner but not professional quality!
Fantastic video. Rushing home after work to do this
Haha cool :) you in Australia?
I tried both ways (i.e., testing and doing the math measuring the distance at the minimum setting and at a selected torque setting prior to adding the weight) and the first/original explanation seems more accurate. If you set the torque setting before measuring, the math equation simply doesn't work. In short, in my view, the original comment made in the video was and is correct. Either way, you have superb communication skills and a equally great demeanor. You'd be an excellent Professor.
Thank you for the kind words :)
Just couple your click wrench to a beam wrench. The beam wrench is ALWAYS accurate as a calibration reference.
Most people don’t have a beam and click
Aviation regulations require clicker wrenches to be calibrated every 12 months to be legal to use on aircraft. Beam type wrenches do not ever need to be calibrated per FAA regulations.
Questions/comments:
1. You confirmed the weight of the sugar bag, dumbell etc …..using “a scale”.
How do you know THAT measuring device is accurate?
2. You tested the torque wrench at ONE place. A proper calibration would test it all the way up and down the range it is used at. (It could test great at 20 ft-lbs, but be hopelessly off at 40 ft-lbs.
Hey! Lots of great questions, all I can say is that it has given me very accurate and consistent results for a long time. Whenever I compare it to another torque wrench it’s spot on and after all, it’s just used for small engine repair, it’s not used by NASA :)
Great video! One thing though...
"Bang-on" is a metric term, the inch torque wrench is what we call "dead nuts"
I don't make the rules 🤷♂️
🤣🤣 that did make me laugh out loud, thanks for that 😂👍
One issue, the spring inside is not linear, I.E., it may register too low on a light weight setting and register too high on a heavy weight setting.
I believe the best practical area to calibrate is around the center of the range, and preferably around the torque where you most intend the tool
Yep, where you intend to use it most
You forgot to reposition your weight point after changing the setting on the wrench, if you change the setting, your weight point moves with the handle since the handle extends/retracts so you need to get your measuring tape back out and look where your weight position is now.
Thanks for watching. Yep it was an editing mistake.
2:14 supposed to hang the weight at that line, that line is there to indicate the length used for calibration purposes
Thanks for sharing!