@@richardcloudbase and what exactly does gravity have to do with it?! exactly... nothing at all in this case ;) and his calculation is right. to be more precise: 30,59148639047619kg at an length of 42cm
Putting aside almost everyone elses comments about calibrating the scales and what scales to use and what colour socks you should be wearing etc, it is a very useful video in that you are showing the basic principle of adjusting a torque wrench. I didn't realise that they were adjustable as I have never given it a thought. I will be checking mine now. thank you.
You can eliminate the imprecision of the spring scale by using the water vessel directly on the torque wrench. Hang the vessel on the wrench and add water using a measuring cylinder in precise quantities. I used a similar set up to set the dynamic torque value when preloading the input bearing on a differential. 2:11 btw. This adjustment is merely a zero. To fully calibrate a scale there needs to be a span adjustment too. to compensate for nonlinearity in the mechanism. This is why I recommend using the weight of water directly
@@Yaroslav_Tselovanskyi More precise, but there are inherent problems with scales that hanging a weight off the wrench eliminates. One is that angle of force will always be the same on a horizontal wrench handle with a weight ,but pulling a balance depends on how good your eye is. All cheap scales are nonlinear , even electronic ones. A good compromise is using a precision scale to weigh the test weights (water) you calibrate the wrench with.
@@paulg3336 I don't see the electronic scale precision to be the issue here at all, even the cheapest electronic scales (like the 50kg one I own) have the error of just 10g, it's nothing for this kind of task, it's literally a margin of error even when you use water or whatever.
@@Axbear yeah, but those valve springs don’t have to be as precise as the spring in a torque wrench. Are torque wrench manufacturers etching the instructions to store at minimum setting just to annoy their customers?
If you’re going to make a video about torque wrenches, make sure you always leave a tip by saying always take the tension off the spring in there before you put it back on a shelf for any period of time. Any spring left under tension will diminish in storage. Never adjust a torque wrench to like 240 ft/lbs, do a bearing and then stick it back in the tool box to store without taking all the tension off.
@@markmcgoveran6811 I'd never buy a torque wrench through a place like a pawn shop. This video was indeed very helpful but if that spring has been abused and neglected, I don't know. They're not an arm and a leg through Amazon and it's brand new out of the box.
@@kirkthiets2771 I'm very happy for you that you live such a wonderful life. I've been a lot of places where it was a couple hundred miles round-trip to go buy a torque wrench.
We never took the tension off, but it wasn't anything accurate. Just small stuff like cruise ship engines/power plant engines. And still every yearly calibration they were in spec
Welll... you learn something new everyday, i was today old when i learned you have to calibrate a torque wrench. The more you know the better, knowledge is everything!
Until seeing this video I was content with knowing bolts at least were tightened equally. Now I must see if it is in fact accurate. Thank you sir. Great video
with the formula applied for the length of the arm (Arnold chose 42cm in this case) the result is equally accurate as when calculated for the groove in the handle; it would just read higher on the scales than 30kg as the arm is then shorter than 42cm, the shorter the arm the more force is required, but the force on the center (the moment of clicking) does not change.
@@ronb4178 Constantly amazed at the re-invention of the wheel. Take a tool that is designed to be used a certain way; and throw away the rules and how the tool is constructed; and do it 'your way' or "I want to use it this way." And we're stating this with a Measuring, Calibrating tool - which has a specific place, a specific point - and only One point/place to be evenly pulled from. Bryan Hau - is totally correct. And I am aware - that for example - the FAA coming in on a Mechanic using a torque wrench - are not going to accept anything - except pulling the wrench from where it was designed and manufactured to be pulled. And you get to do a bunch of insane calculations if the nut hasn't easy access and your using a crows foot or some such - but those tools have described methods of angle and measurement calculations to be determined with the wrench. However - all of that - is ALWAYS determined still with pulling the wrench in an even pull - at the point where the wrench was designed to be pulled.
I could be wrong, but I failry sure the smooth groove in the knurling of the handle is actually the calibration point for your spring scale, rather than the tip end of the handle.
Schwarzenegger? No one better to discuss torque. Thanks for this video. Always figured my inaccurate torque wrench was better than my guesstimation. Now I'll sleep better.
1st ! After half a century of working on bicycles - cars - engines, and making mistakes, I also have learned "The Feel" like as are used on cylinder heads which absolutely require precise torques, and indeed precise sequences of applied torques. Awesome video that exalts the superior Metric system - 1cc oh H2O = 1gm of weight - thus it is VERY easy to remember too!
some head bolts are tight + some amount of turn. I recently ran into this with a modern axle nut where you brought it snug and then turned it 3/4 a turn more. The turn method gives a particular amount 'more' based on the ratio of the threads and some people swear by that. Of course it all depends on where you started with the 'snug' bit.
notice the torque wrench was adjusted fairly high when you 1st showed it. Instructions with all my torque wenches say to back off setting to lowest (10ft #) for storage.
Allrighty folks, since this video got a lot of comments, I'd like to thank you all for watching. I'll make a Part 2 to adress some questions and do a follow-up. The math I used is: Nm = force x armlength , 126 = Force x 42 , so force = 126nm / 0,42m = 300N, = 30kg. ( 1kg=10N) Please note that this video is intended for home mechanics who want to check if their torque wrench is in spec. If you do customer work, you might want to get an expensive torque wrench and have it regularly calibrated. If any torque wrench manufacturer is watching this and feels the need to send a home mechanic on a budget a nifty torque wrench, please contact me!
@@momanskiakabiffbuz6004 Started commenting and I can see that I got the same result 30.59kg since this 9.8066 comes from gravity....... and then i started thinking if this test will make any difference if you are making it in vertical or horizontally. I have always done it so I hang preweighted weights to the tool and calculate the tool nm to whatever weight I have. But if you hang something then would you have to account the quite a small but still existing weight of handle of the tool? But how would you even calculate it since its unevenly distributed across whole handle length. Another thing worthy of note is that tool should be "heated", meaning before using/measuring it should be cranked 10-15x time make the grease in there a bit warmer and thus result more repeatable. Also i have seen quite a few wrenches where it can read one value , but will be shockingly off at the other end. So it should be done on multiple weights to be sure that tool is good.
@@arva1kes it's not the matter if the force is horizontally or vertically applied, the problem is that you use a measuring device for mass. And when you want to calculate force which is a product of mass*acceleration you have to consider 9.8m/s2 as acceleration factor Sorry for the bad English btw hope you understand something 😅
@@arva1kes To measure the force the weight of the wrench is adding to the test weights, you can hold the square drive in the vise and let the handle rest on a electronic kitchen scale. making sure that everything is within the free play that the ratchet introduces ,so that the vise is not adding to or subtracting from weight of the wrench.
Nice video Arnold. I would say this … a lot of people like to comment on other peoples videos about things they should have done or not. People kind of miss the purpose of the video , which is showing other a DIY process. Personally wanted to say thank you for taking the time to share this DIY process. Good job.
hi juniorclassic have you become a flat earther yet? If not I suggest watch a 13 part series called _What on earth happened_ by Ewaranon to learn that the earth is not a globe. I got it in my about tab.
It is painfully obvious that you and the video’s creator have absolutely no understanding of the concepts of calibration . See my post. The operator is not even applying the force at the center mark. This video should have a disclaimer saying performed by a utterly untrained hack. This is why legitimate calibration labs put tampering seals on tool calibration adjustments.
@@lauraradigan4114 it’s more sad to have hater comments thing’s like this. Every one knows you tube is an open platform where many DIY people go to get an idea of things. I can assure that I know about calibration. But my initial comment on this video was just giving this person a complement. For the creativity. I could have said the same things you toss, trashed back at me for supporting a you tube fellow. I do have an engineering degree as well a BS in microbiology. And in microbiology we need to assure equipment is properly calibrated. But instead of downing this person I opted to give him a complement. And that is all what I wanted to do because the first thing other see is the one bad thing that person made. So that being said. Why won’t you make a calibration video so you can show other the correct way. Perhaps Arnold can also learn something new.
@@juniorclassicvwbugs924 Also juniorclassic if you want to watch a flat versus globe debate I suggest watch a video on Modern-Day Debate called _FE DEBATE: Austin @WitsitGetsIt & @flatearthtests9708 Vs @MrSensible & @culturecatz_
This is correct. It does matter on click type torque wrenches where your hand (or force in this instance) is positioned on the handle. The groove is actually there for a purpose. It is the location where the users hand should be centered to get an accurate torque value. Positioning the point of applied force to the bottom end of the wrench lowers the torque delivered at the socket attachment point. If you choke up on this type of torque wrench more torque is applied at the socket attachment point. Here's a good video that demonstrates this: ruclips.net/video/Fwfnf06dl84/видео.html
Then applying force to the torque arm, always make sure the load you are applying is perpendicular (and stays perpendicular as it winds up) to the torque arm, or you won't be torqing with the load you're measuring. Also, make sure it's on plane for the same reason.
Great video; many people probably don't bother verifying the calibration at any point in a torque wrench's life. Also, the ball bearings in a mechanical torque wrench are critical to accuracy; they can develop flat spots that can throw off the calibration and give inconsistent values. Sometimes, but not always, repacking the grease can clear inconsistent accuracy. At any rate, check the accuracy at several click points in a given arc. 1) Never ASSUME that the calibration is spot on. 2) Check it at high end, low end, and mid range. 3) If it gets dropped, cycle it through its range three times.
Glad someone else noticed this, I was going to comment the same. Having the scale at the furthest point changes the leverage force. With how little he had to adjust it, it was probably accurate before the adjustments
Not necessarily true because it depends on the distance the force is applied from the pivot. For example, if you can apply the force at the 1 metre point and you are applying the specified force for the setting on the dial, that may be correct. The breakout force of the mechanism may be compensated for any length handle, so you have to calculate the force for the distance from the pivot.
@@chrisbode7173 Sorry but that's not correct. The mechanism works independently of the point of application of the force. The handle or whatever you want to call it is metal tube - it doesn't care or feel where you apply the force. Of course, if you apply the force at a point other than on the defined hand-hold, you would need to apply more force if nearer the pivot, or less force if further away. Try it and see. You could even extend the length of the handle with a piece of tubing of you like and that will reduce the force needed, but the breaking mechanism will still operate at exactly the same torque setting. There's no mathS required - the calibration of the mechanism does all the work.
@@125brat you're correct. I made the mistake, indeed the wrench does the work for you as you write here above. Doesn't matter from what position and with what force. Sorrry.
remember if you measure at 12" a point then is lbs for lbs. But if you have a longer torque wrench, you need to divide by 12 in the calculation to be exact ft .lbs@@Carnold_YT
This is more likely to help many DIY'ers screw up the calibration of their torque wrench. Torque is based on the amount of force at a specific distance from the pivot. Without measuring the distance from pivot to scale placement, you will screw up the calibration.
Here in Glasgow I put my cycle into a cycling shop and had various problems with the pedal stem slipping off and being buggered. One day whilst my cycle was in the shop an engineer phoned me to tell be his wrench was calibrated against another and found to be off by quite a bit.
I have exactly the same model of torque wrench, after 3 years of very infrequent use of this wrench came out the result of 27 kg of the required 30 kg. I think it is pretty good for 3 years without calibration. Now at least I know how to get down to calibration ;)
One thing to note: almost all scales are most accurate at their mid range, so they should be checked against multiple masses (the water). You would also want to use a scale that is smaller in range, since most mechanical scales are not accurate at the low and high sections.
@@lperea21 There are two things. First thing, the handle of the wrench should be 1m, which is not, but you can always compensate by measuring the water. 50Nm is roughly 5kg with 1m handle. Fun part is when you have to make the wrench "stiffer", and then loosen the adjustment, so it'll snap on the 50Nm mark. So, make a longer handle from a pipe, or some calculus with water, but I think it's more precise with that scale. Then you can actually see, what weight made it "snap".
A lot of almosts. Too many for my money, including mid range. All that matters is WHAT YOU HAVE. Maybe someone has a good scale, good fresh calibration showing it's deviance from true across it's entire scale. Take these lessons for what they're worth.
Thank you for this video. I always thought that as long as my lug nuts were consistent with each other that would be keep my rotors from warping. Being able to check my Harbour Freight wrench for accuracy is great.
Most people don't know this but most things don't have to be at some super exact torque spec. There is a range and if something is in that range then it's fine. If there are multiple bolts then it's usually important that they are the same torque. So if you're within the torque range and all of your bolts in an area are tightened very equally at the same torque then it's usually okay. So if a torque wrench is off by like 1.5 lbs at a 60lb torque spec then it usually doesn't matter. Actually most things have a larger tolerable range than that. If you're building a thousand horsepower engine then you should invest in an expensive, accurate, calibrated torque wrench though. Or if you're doing aerospace stuff.
Extremely helpful Arnold, had an old one like this for years and years but one time my young son got his hands on it and suddenly it was in pieces, I reassembled it but was never happy so just purchased a new digital one, had I seen your video sooner I could’ve saved a $150, so now armed with this new info it’s time to play with my old torque wrench😃, thanks for sharing Arnold.👍
As a sanity check, I've checked my adjustable torque wrench against a deflecting beam one coupling the drives together. I wouldn't calibrate my wrench this way, but have checked it for drift this way. It works great.
I really enjoyed this video, thank you!Another method for calibrating anything (torque wrenches today) is to compare two or better still three other wrenches. If you haven't got more than one perhaps borrow one and compare them and particularly if all three actuate the same that's pretty good test. You can also use the method of setting to an angle, clamp square drive in the vice, set up all wrenches to the same setting and with the angular unit note the angles that each wrench clicks. If they all break at the same angle you have three pretty good wrenches, if not you can self calibrate or get them checked by a calibration service. Especially good makes of mechanical ones are expensive to replace and worth the cost if in good condition. This method has proven to be pretty good over the years as I on several occasions had access to a proper test facility so was able to double check results.
I've thought about this too. I have a chinesium Click stop torque wrench and have wondered about accuracy. I don't have a scale so will use five gallons H20 to see if close. Also must allow for +/- Lbs. on wrench setting. Thanks for posting.
changing your grip affects the amount of torque you're applying at the head of the torque wrench, but it doesn't change the actual amount of force that has to be applied at the head to make it click. It changes the amount of force that has to be applied to the handle to make it click, but it still clicks based on the amount of torque being applied to the head/fastener regardless of how you're gripping it. so you can grip it at any spot and get the same results if you're just going by the click
It does change the reading (on the scale) of course. For instance ft-lbs is the amount of fource you would be pulling on the handle at a ft from the actual tip. So it does matter how far away the scale is on the handle, but i think you already understood that lol.
I guess another useful bit of info when doing the calibration is keeping the spring scale or water bottle etc. perpendicular to the torque wrench! Good tutorial. 😎
When refurbishing the steering gear on my '67 F100 I needed a 7-10 inch-lb. torque wrench so I made one using a wooden dowel and a 1/2" carriage bolt with the head cut off to drive the socket. The tricky part is getting the value of a known weight to hang off the handle. (I think it was a 3/8" carriage bolt)
I make a straight coupler, 1/4”, 3/8”, or 1/2” from two old sockets welded together. Annually, I couple my beam style torque wrenches to my click style clamped gently in the vice. I do three checks using a setting at the lower third of the scale, the center of the scale and the upper third. If the wrench clicks within 3% of the set torque across the board - good to go. If it doesn’t, I adjust the tension and retest until it passes. If it fails to adjust, it’s time for a new wrench. Beam style torque wrenches are non-adjustable and as long as they are not over torqued and bent/deformed, they are accurate in both directions.
This is exactly what I was going to post. Beam wrenches are always accurate, just not very user friendly in places where you can 't see the sale. So you always use them for calibration. One thing I haven't seen mentioned here is that accuracy is always a percentage of full scale. So a 100 lb ft wrench of + or - 2% means + or - 2 lb ft. If you have it set for 20 that's still 2 lb variance so 10% at that setting. Which is why you want to use a 25 lb ft wrench if you're trying to set 15-20 as a 100 can be waaay off.
Thank you so much for posting this! My old torque wrench has been unused for a few years and never calibrated since new. I need to replace head gaskets on my vehicle, and I was considering buying a new torque wrench. This just saved me a bundle! Thanks again!! BTW my wrench is identical to yours, except graduated in lb.ft., purchased at Princess Auto in Canada.
Excellent to know. I used to work in mechanical measurement within precise Engineering. I never calibrated a torque wrench, somebody else always did them regularly! I used to calibrate mics tho.
Excellent video! I have a couple of cheap torque wrenches myself with varying torque range values and I will definitely use this technique to check and calibrate them if needed. An average of +/- 5% of error is more than enough for your average backyard mechanic.
Great video. Although you missed some of the best bits. How did you calculate that 30 kg? At least a link to how to the calculation would have been handy. How did you get the lock not off the handle. It was magically gone. I would not have thought of doing this. Thanks for sharing
Davo's Shed, the torque wrench is set at 126 Nm. From Newton to kg, you have to divide by 9,81. That makes 12,8 kgm. Divide this value by the distance in meters from pivot point to where you apply the pulling force. In the video that is 42 cm, thus 0,42 m. 12,8 divided by 0,42 makes 30,6 kg.. To make it easier for yourself, put some painter's tape on the handle, make a mark at 42,8 cm and apply 30 kg of pulling force. Is more accurate.
@@chrisbode7173 very interesting! That 9.8 is curious. Sounds like the good old metric system has something to do with that being acceleration due to gravity. I better did out my old torque wrench. If I remember correctly mines not adjustable, it’s just the bending force on the handle. It’s an oldie not a goodie. :)
@@DavoShed Correct, 9,81 m/s2 is the acceleration due to gravity. I've worked with torque wrenches based on the bending force of the handle. They give a better understanding of the torque phenomenon. Great!
I took a Herber Fraught $19.95 1/2" torque wrench to the calibration place here in town and paid my $60. It wasn't perfect or LINEAR by the scale, but it was with-in I think 8% across the board, which for a "clicker" (and automotive use) is "close enough" if you aren't building race engines. The WAY YOU use it will make MORE than an 8% difference. Like "just tighten and go" or "lube fastener, tighten, loosen, re-tighten to spec'd torque" or "tighten to spec, let sit an hour(2-4) loosen, re-torque" or whatever the procedure you are SUPPOSED to use. The $5500+ electronic wrenches are supposed to be calibrated (about a grand) YEARLY. If you're working on jet turbines or turbosuperchargers, you NEED that precision.
I found working on motorbikes where you get a steel bolt into a aluminum hole to be very careful as an oily well used bolt will easily strip the alu threads sticking to the recomended torque value..feel is everything . I think torque values are often given for a `dry `bolt also so reduce a bit if oiled .
That is correct, most workshop manuals don't state whether or not a bolt should be oiled. But applying a coat of oil will definitely affect the clamping force of the bolt (or nut). Especially with lightweight alloys, you should be careful. I personally like use my normal ratchet and tighten the bolts by feel in that case.
I thought this was a great video, thanks... I'll probably have to watch it a 100 times more before I really attempt it but it seemed very logical . Again thanks
Two effects occur. One is that the rigidity modulus changes. For most materials this means they get less springy as heat rises. In the case of a torque wrench the actual torque drops compared to the displayed value on the handle scale. Second is parts of the wrench physically expand as the heat rises and this also has the same effect as above.
Bedankt voor de tip. Ik wist eigenlijk niet dat je zo'n sleutel zelf kon kalibreren. Voor een gelijkaardige momentsleutel heb ik in het verleden een omrekentabel gemaakt. 'Die waarde' instellen om 'dat moment' te krijgen, maar zo'n herkalibratie is natuurlijk minder gedoe tijdens gebruik.
Good video, very clever I recently watched a video saying for spring-loaded torque wrenches in order to be absolutely accurate. They have to be “warmed up” first which means work them from 0 to maximum in steps of 10% and then back down the other way to put some heat in the spring and some heat in the grease internally that’s clearly for high precision engine jobs and stuff like that.
for many years I used a deflection (beam) wrench. I figured that it was accurate if you could see the indicator, but with the way my eyes are now, it is tricky changing glasses.
I use your method on my cheapo one but my ancient airfitter's King Dick elbow torque wrench the only way is to replace the inner tension spring to calibrate and this thing is old old old but its pretty accurate still all these years on, very heavy too but cumbersome in you have to remove the end cap, use a spanner to wind the adjustor in and out, replace cap to see if its set correctly and so on as it is designed to be used all day long at certain torques. Apparently from what I have been told your airfitter or plane mechanic would have several setup and taped with different torque ratings on his trolley, then end of day the things unwound til next day when they would be wound back up to different torques, the elbow ensures perfect torque application thus you get very precise settings.
Having a beam style torque wrench is ideal for checking any other (affordable) torque wrenches. I mostly use it for lug nuts to ensure everyghing is tightened evenly.
I thought the line between the knurls on the handle, marks the position where the torque wrench is calibrated. I wonder how much difference it would make, putting the scale on the very end of the handle (like you did), and on the calibration line.
You can apply the test force anywhere along the handle as long as you compensate for the position in your calculations. It's easiest if you select the distance to match the units you are using i.e. 1 ft from the pivot if using ft-lbs or 1 m if using kg-m. It's ok to extend the handle with a lightweight rigid tube
@@paulg3336 they are designed center of handle for calibration. It will click at the same torgue with the force applied nearly anywhere after the pivot as the tube is stiff enough to react the forces without deflecting an appreciable amount. For calibration purposes, the center of applied force is assumed to be the center of the handle.
@@deanelewis5043 That is where you apply the force when you use the wrench. To test the wrench: *You can apply the test force anywhere along the handle as long as you compensate for the position in your calculations.* Read what I wrote The test force can be any weight at a suitable distance from the pivot to achieve the test torque
I use a harbor Freight digital torque adapter and a socket that fits my lug nuts on the car. Set the adapter to hold a reading and use it on one of the lug nuts that in on my car's wheels with a torque wrench. When the torque wrench clicks I look at the reading on the digital adapter to see how close it is to the set point on the torque wrench.
Great work. I would have wanted to see a bit more accurate calibration method but water in plastic container but I guess that's good enough for the scale used here.
And with the accuracy of the torque wrench in mind, I don't expect accuracy up to 1 nm, but I wanted to make sure that my wrench is in spec in the range I use most. Part 2 is coming soon!
I did use a calibrated torqwrench connected to (check) the other cheap torqwrench ,mij offset was 0,03 percent verry happy ,most car workshops own a calibrated one and a checkup is easy to fix ,most mechanic are willing help to test yours (for free ?)
Hi, I wanted to do two tests after calibrating it: my key is small, 5 -25 nm, I set a weight of 2.6 kg at 20 cm that clicked at 5 nm and calibrate it. I wanted to do a new test with 4.6 kg at 20 cm result 9.1 nm but it doesn't click. I calibrate at 9.1 nm by loosening the spring tension but when I try the 5 nm again with the 2.6 kg from before it clicks much sooner. I recorded from the bottom dial. I don't have the same calibration for the various measurements.
I learned that it is important to 'work' a torque wrench before using it, or before calibrating it. It is basically a warming-up procedure: set the wrench to a low setting and 'tighten' a bolt, and let it click a few times. Then you raise the setting of the wrench and repeat it a couple of times. Once it is worked, you can start using or calibrating it. You should first test it across the range (from 5, 10, 15, 20 and 25 Nm) and then see where it deviates. I kept adjusting on low and high settings until I got an overall acceptable result. In this video I tried to adjust the torque wrench to be accurature in the range that I needed. Thanks for watching!
@@Carnold_YT and yet, you pull at the end of the grip on the black part. If you pulled at the narrow blank part, the force would probably be spot on. Addition: I know all this is better than nothing (hopefully) and on a principle basis, but calibrating something at 5kg, and then use it at 30kg, is not exactly by the book either. But again, I understand the accessibility of a 5 liter can (I have several in the shed). Other than that, great video! I've never checked my torque wrench, but perhaps I should. PS. Keep up the good work with the Lexus - one of my dream cars!
I used the good old formula: Torque = force x length of arm. Maybe you find this online calculator helpful: www.omnicalculator.com/physics/torque Thanks for watching!
Could not see which way you were turning the inside but i now have the jist of it, i did not know you could calibrate them yourself I just assumed you could trust from the factory or do you have to do this every so often?
I check mine every time I do large maintenance. I don't expect it to be accurate over the entire range, but I want to make sure that it is accurate in the range I need for the task. That is what I check often.
Force needs to be applied in the center of the hand grip. The handle pivots in front of the ratcheting head so the calculation from “center of the socket” to end of the handle is not correct.
Turing the adjuster clockwise will increase the pressure on the click spring. This is what you do if the wrench clicks too early. If the wrench clicks too late (when it is overtightening), you have to loosen the set screw.
Great video! I looked up the math and found that 1 newton meter [N·m] = 0.1019716212978 kilogram-force meter [kgf·m]. So 126 N·m * 0.1019716212978 = 12.852 kgf·m. And since the distance from the applied force to the point of rotation is 42 cm or 0.42 m, 12.852 kgf·m / 0.42 m = 30.6 kg. So now I see how you arrived at 30kg of force. One question - When your torque wrench was clicking at 25 kg, did you adjust the calibration clockwise or counter-clockwise to dial in the torque closer to 30 kg? As a Canadian in my 50s I use a real mixture of imperial and metric. No question that metric is the superior system, though I still tend to think in terms of foot pounds because that's what my Dad passed on to me. 🙂
When the torque wrench clicked too early, I increased the pre-load on the spring, so it requires more force to click. To increase the pre-load, I turned the adjuster in (clockwise). I only took 3/4 of a turn to correct the pre-load. I can relate to your story on mixed standards, I used to be a technical writer that's used to the metric system, but I have written many workshop manuals for the US and Canadian market. The conversions weren't the hardest part, I am so used to use a comma (,) as a decimal point, that I always needed to remind myself to use a point (.) instead. Anyways, thanks for watching!
I concur. Try going through the CMHC wood-frame builders handbook, you have to constantly convert everything from odd-ball mm sizes to 2x4 or whatever. I am not sure who in Ottawa thinks I head into Home Depot to buy a 1219mm x 2438mm sheet of anything. !
I talked to a guy once who pointed out that the romans split the inch into 16ths and that 12ths were superior because you could more easily divide them. This in turn points out the problem with the metric system which is fractions are hard when all you can divide evenly are 1, 2, 5, and 10. Now... if you live in a metric world do you still buy a dozen eggs or are there only 10 in the carton :)
in my opinion you should apply a scale hutch on the middle of grooved place because right nowyou use it differently than normal. your hand should have grip around a center of hand position not far away in the end. so maybe originally near 30 was good.
@@deepcangler they work on force needed to slip mechanical part tensioned by spring. Because this is measure in Nm usually it's mean that force attached to the arm it's correlated another force in fixed arm and fixed slip, resistance. So if you change length of the arm with the same force you change torque. So if you calibrate torque you should apply force the same place. Later after calibration it's not important when you put force as soon you exceeded torque it clik or slip. But with calibration it's one of the most important...
Nice job and great instructional video!...but I prefer to call such tools a Torque Gauge! because every wrench is a torque wrench, because it applies torque, but a Torque Gauge measures it (or in the case of the click type, even limits it). Cheers from my garage to yours!
My dad worked on aircraft in the 50s and 60s then testbeds in the 70s. I need to use a torque wrench but somehow his arm is amazingly precise he knows exactly what 100nm feels like to within 5nm. On top of that, he ended up in technical publications where the torque settings were decided and its a mixture of finger in the wind mixed with measuring what an engineer thought felt was right. The exception was torque to yield but thats a completely different thing. He still maimtains you only need a torque wrench to get consistency for people who don't understand what they are doing. I can't feel 100nm from 200nm. Obviously 200 is twice but when you cant get square on something or your arm at a funny angle I just can do it... he still can.
Thanks for sharing that story James. I completely agree with your dad, I've been a technical writer for over 20 years now and determining torque values for workshop manuals is often done by what experienced mechanics feel what is right. If we needed a torque value, we just measured the breakout torque and went with that. As I said in the start of this video: I like to work by feel an in my opinion any good mechanic can do that. On safety critical components, high torque connections and in the aerospace industry, it is a whole different story. That's where the calibrated and certified stuff comes in. But then again, in my day job I see a lot of overtightened bolts that just snapped off because the recently calibrated (they're always recently calibrated when stuff happens) beeped when the set torque value was long exceeded.
Your Father had the 'calibrated arm', as we used to say in the Aircraft sector. The old German torque of 'Guden' Tite' was the other expression we would jokingly use.
On aircraft (there is no Parking Garage in the sky) - it is ILLEGAL for a mechanic to tighten a nut or bolt which has a called out torque - and not to use a certified Torque Wrench. You must sign documents attesting to your work when finished. Crud - the FAA will fine a mechanic - if they come to a shop or Airline; and find an individual working on an Aircraft without the Documents and drawings stating what to do and how to do it - at his location and readily available.
If I don't have a fancy spring scale to pull on would a cheap digital luggage scale work and possibly be more accurate across its range than your water calibrated spring scale?
@@Carnold_YT it certainly wouldn't look as good as yours does in the video. I'm going to test an over 50yo snapon dial torque wrench or as the dial reads 'torq meter"
The math I used is: Nm = force x arm length , 126 = Force x 42 , so force = 126nm / 0,42m = 300N, = 30kg. ( 1kg=10N)
What planet do you live on? On my planet gravity is 9.81 m/s2 :)
@@richardcloudbase and what exactly does gravity have to do with it?! exactly... nothing at all in this case ;) and his calculation is right. to be more precise: 30,59148639047619kg at an length of 42cm
@@richardcloudbase so is g a constant on your planet?
@@martinkrabowski2057 1kg = 9.81N not 10. That’s what he meant. So the more accurate measurement should be 30.58103975535168
The math I use is: pay more for a better torque wrench.
Putting aside almost everyone elses comments about calibrating the scales and what scales to use and what colour socks you should be wearing etc, it is a very useful video in that you are showing the basic principle of adjusting a torque wrench. I didn't realise that they were adjustable as I have never given it a thought. I will be checking mine now. thank you.
BEST comment!
It would have been good to use lbs
Why?
True. But which colour you recommend for the socks?😂
You can eliminate the imprecision of the spring scale by using the water vessel directly on the torque wrench.
Hang the vessel on the wrench and add water using a measuring cylinder in precise quantities.
I used a similar set up to set the dynamic torque value when preloading the input bearing on a differential.
2:11 btw. This adjustment is merely a zero. To fully calibrate a scale there needs to be a span adjustment too. to compensate for nonlinearity in the mechanism.
This is why I recommend using the weight of water directly
Very true 👍
No shit sherlock
or use electronic scales
@@Yaroslav_Tselovanskyi More precise, but there are inherent problems with scales that hanging a weight off the wrench eliminates.
One is that angle of force will always be the same on a horizontal wrench handle with a weight ,but pulling a balance depends on how good your eye is.
All cheap scales are nonlinear , even electronic ones.
A good compromise is using a precision scale to weigh the test weights (water) you calibrate the wrench with.
@@paulg3336 I don't see the electronic scale precision to be the issue here at all, even the cheapest electronic scales (like the 50kg one I own) have the error of just 10g, it's nothing for this kind of task, it's literally a margin of error even when you use water or whatever.
Always leave a wind up torque wrench in an unwound state!
🙈
You mean at minimum torque setting? If so, yes.
It’s a myth. The spring will not take any harm to be left in tension. Think of all the valve springs in million of cars.😊
@@Axbear Valve springs are not under much tension. Coilover springs are known to soften over time
@@Axbear yeah, but those valve springs don’t have to be as precise as the spring in a torque wrench. Are torque wrench manufacturers etching the instructions to store at minimum setting just to annoy their customers?
If you’re going to make a video about torque wrenches, make sure you always leave a tip by saying always take the tension off the spring in there before you put it back on a shelf for any period of time. Any spring left under tension will diminish in storage.
Never adjust a torque wrench to like 240 ft/lbs, do a bearing and then stick it back in the tool box to store without taking all the tension off.
Quite right and that should be mentioned in the tools instructions
@@bsimpson6204 it would be great if you would mention it because the guy might have a torque wrench and he got used.
@@markmcgoveran6811 I'd never buy a torque wrench through a place like a pawn shop. This video was indeed very helpful but if that spring has been abused and neglected, I don't know. They're not an arm and a leg through Amazon and it's brand new out of the box.
@@kirkthiets2771 I'm very happy for you that you live such a wonderful life. I've been a lot of places where it was a couple hundred miles round-trip to go buy a torque wrench.
We never took the tension off, but it wasn't anything accurate. Just small stuff like cruise ship engines/power plant engines. And still every yearly calibration they were in spec
Unfortunately as an aircraft mechanic I cannot self calibrate as I have too provide a certificate. This is superb for diy mechanics . Kudos to you
Thanks for watching Roger!
Welll... you learn something new everyday, i was today old when i learned you have to calibrate a torque wrench. The more you know the better, knowledge is everything!
Until seeing this video I was content with knowing bolts at least were tightened equally. Now I must see if it is in fact accurate. Thank you sir. Great video
It’s my understanding that the force needs to be applied to the center of the knurled handle. That may be the purpose of the groove in it.
Absolutely and correct.
with the formula applied for the length of the arm (Arnold chose 42cm in this case) the result is equally accurate as when calculated for the groove in the handle; it would just read higher on the scales than 30kg as the arm is then shorter than 42cm, the shorter the arm the more force is required, but the force on the center (the moment of clicking) does not change.
@@ronb4178 Constantly amazed at the re-invention of the wheel. Take a tool that is designed to be used a certain way; and throw away the rules and how the tool is constructed; and do it 'your way' or "I want to use it this way." And we're stating this with a Measuring, Calibrating tool - which has a specific place, a specific point - and only One point/place to be evenly pulled from. Bryan Hau - is totally correct. And I am aware - that for example - the FAA coming in on a Mechanic using a torque wrench - are not going to accept anything - except pulling the wrench from where it was designed and manufactured to be pulled. And you get to do a bunch of insane calculations if the nut hasn't easy access and your using a crows foot or some such - but those tools have described methods of angle and measurement calculations to be determined with the wrench. However - all of that - is ALWAYS determined still with pulling the wrench in an even pull - at the point where the wrench was designed to be pulled.
@@daves7775 Ok mate, enjoy your day now.
People have too much time@@daves7775
That's enough internet for today.
I could be wrong, but I failry sure the smooth groove in the knurling of the handle is actually the calibration point for your spring scale, rather than the tip end of the handle.
Exactly. This video is all wrong!
Schwarzenegger? No one better to discuss torque. Thanks for this video. Always figured my inaccurate torque wrench was better than my guesstimation. Now I'll sleep better.
Arnie is not a Dutchman, clever cloggs. 😉
That is exactly the type of torque wrench I have, so for me this instruction was perfect!
1st ! After half a century of working on bicycles - cars - engines, and making mistakes, I also have learned "The Feel" like as are used on cylinder heads which absolutely require precise torques, and indeed precise sequences of applied torques. Awesome video that exalts the superior Metric system - 1cc oh H2O = 1gm of weight - thus it is VERY easy to remember too!
What was your math formula.?
1cc of PURE WATER not tap or any mineral
some head bolts are tight + some amount of turn. I recently ran into this with a modern axle nut where you brought it snug and then turned it 3/4 a turn more. The turn method gives a particular amount 'more' based on the ratio of the threads and some people swear by that. Of course it all depends on where you started with the 'snug' bit.
Or, in old money, 1pt water = 1lb and a quarter. Easy to remember 'coz it rhymes!
@@dolvaran in Britain it depends on which gallon and which pound. In the US 'a pint is a pound the world around' is reasonably accurate for water.
notice the torque wrench was adjusted fairly high when you 1st showed it. Instructions with all my torque wenches say to back off setting to lowest (10ft #) for storage.
Allrighty folks, since this video got a lot of comments, I'd like to thank you all for watching. I'll make a Part 2 to adress some questions and do a follow-up. The math I used is: Nm = force x armlength , 126 = Force x 42 , so force = 126nm / 0,42m = 300N, = 30kg. ( 1kg=10N)
Please note that this video is intended for home mechanics who want to check if their torque wrench is in spec. If you do customer work, you might want to get an expensive torque wrench and have it regularly calibrated. If any torque wrench manufacturer is watching this and feels the need to send a home mechanic on a budget a nifty torque wrench, please contact me!
126 Nm not 136 Nm ;)
1kg is 9.81 N so 300n is 30.6 kg
@@momanskiakabiffbuz6004 Started commenting and I can see that I got the same result 30.59kg since this 9.8066 comes from gravity....... and then i started thinking if this test will make any difference if you are making it in vertical or horizontally. I have always done it so I hang preweighted weights to the tool and calculate the tool nm to whatever weight I have. But if you hang something then would you have to account the quite a small but still existing weight of handle of the tool? But how would you even calculate it since its unevenly distributed across whole handle length. Another thing worthy of note is that tool should be "heated", meaning before using/measuring it should be cranked 10-15x time make the grease in there a bit warmer and thus result more repeatable. Also i have seen quite a few wrenches where it can read one value , but will be shockingly off at the other end. So it should be done on multiple weights to be sure that tool is good.
@@arva1kes it's not the matter if the force is horizontally or vertically applied, the problem is that you use a measuring device for mass. And when you want to calculate force which is a product of mass*acceleration you have to consider 9.8m/s2 as acceleration factor
Sorry for the bad English btw hope you understand something 😅
@@arva1kes To measure the force the weight of the wrench is adding to the test weights, you can hold the square drive in the vise and let the handle rest on a electronic kitchen scale. making sure that everything is within the free play that the ratchet introduces ,so that the vise is not adding to or subtracting from weight of the wrench.
Nice video Arnold. I would say this … a lot of people like to comment on other peoples videos about things they should have done or not. People kind of miss the purpose of the video , which is showing other a DIY process. Personally wanted to say thank you for taking the time to share this DIY process. Good job.
hi juniorclassic have you become a flat earther yet? If not I suggest watch a 13 part series called _What on earth happened_ by Ewaranon to learn that the earth is not a globe. I got it in my about tab.
It is painfully obvious that you and the video’s creator have absolutely no understanding of the concepts of calibration . See my post. The operator is not even applying the force at the center mark. This video should have a disclaimer saying performed by a utterly untrained hack. This is why legitimate calibration labs put tampering seals on tool calibration adjustments.
@@lauraradigan4114 it’s more sad to have hater comments thing’s like this. Every one knows you tube is an open platform where many DIY people go to get an idea of things. I can assure that I know about calibration. But my initial comment on this video was just giving this person a complement. For the creativity. I could have said the same things you toss, trashed back at me for supporting a you tube fellow. I do have an engineering degree as well a BS in microbiology. And in microbiology we need to assure equipment is properly calibrated. But instead of downing this person I opted to give him a complement. And that is all what I wanted to do because the first thing other see is the one bad thing that person made. So that being said. Why won’t you make a calibration video so you can show other the correct way. Perhaps Arnold can also learn something new.
@@juniorclassicvwbugs924 Also juniorclassic if you want to watch a flat versus globe debate I suggest watch a video on Modern-Day Debate called _FE DEBATE: Austin @WitsitGetsIt & @flatearthtests9708 Vs @MrSensible & @culturecatz_
I think you should be pulling in the groove on the middle of the handle
This is correct. It does matter on click type torque wrenches where your hand (or force in this instance) is positioned on the handle. The groove is actually there for a purpose. It is the location where the users hand should be centered to get an accurate torque value. Positioning the point of applied force to the bottom end of the wrench lowers the torque delivered at the socket attachment point. If you choke up on this type of torque wrench more torque is applied at the socket attachment point. Here's a good video that demonstrates this: ruclips.net/video/Fwfnf06dl84/видео.html
Then applying force to the torque arm, always make sure the load you are applying is perpendicular (and stays perpendicular as it winds up) to the torque arm, or you won't be torqing with the load you're measuring. Also, make sure it's on plane for the same reason.
Arnold, very reasonable accuracy for this job! Thanks for the video.
Thanks for watching Karel!
Great video; many people probably don't bother verifying the calibration at any point in a torque wrench's life. Also, the ball bearings in a mechanical torque wrench are critical to accuracy; they can develop flat spots that can throw off the calibration and give inconsistent values. Sometimes, but not always, repacking the grease can clear inconsistent accuracy. At any rate, check the accuracy at several click points in a given arc.
1) Never ASSUME that the calibration is spot on. 2) Check it at high end, low end, and mid range. 3) If it gets dropped, cycle it through its range three times.
Thanks for that useful information. Now I can check the accuracy of my torque wrench without fancy equipment.
Measurement of the arm and scale force must be applied to the middle section of the handle grip. In your case, the smooth band in the grip.
Exactly. The correct distance to use is from center of drive to that ring in the center of the handle. That changes his math a bit.
Glad someone else noticed this, I was going to comment the same. Having the scale at the furthest point changes the leverage force. With how little he had to adjust it, it was probably accurate before the adjustments
Not necessarily true because it depends on the distance the force is applied from the pivot. For example, if you can apply the force at the 1 metre point and you are applying the specified force for the setting on the dial, that may be correct. The breakout force of the mechanism may be compensated for any length handle, so you have to calculate the force for the distance from the pivot.
@@chrisbode7173 Sorry but that's not correct. The mechanism works independently of the point of application of the force. The handle or whatever you want to call it is metal tube - it doesn't care or feel where you apply the force. Of course, if you apply the force at a point other than on the defined hand-hold, you would need to apply more force if nearer the pivot, or less force if further away. Try it and see. You could even extend the length of the handle with a piece of tubing of you like and that will reduce the force needed, but the breaking mechanism will still operate at exactly the same torque setting.
There's no mathS required - the calibration of the mechanism does all the work.
@@125brat you're correct. I made the mistake, indeed the wrench does the work for you as you write here above. Doesn't matter from what position and with what force. Sorrry.
i would do it different, put the torque wrench on the vise vertically and it would be easier to hang the weight and make it click.
That's a much better idea indeed!
remember if you measure at 12" a point then is lbs for lbs. But if you have a longer torque wrench, you need to divide by 12 in the calculation to be exact ft .lbs@@Carnold_YT
It is great to see this done! Even with using analog devices like that, this is easy and will help many DIY'ers! Thank you.
Nothing is as precise as an analog device. I get more feeling for the measurements when it’s analog. You only need to read it right.
This is more likely to help many DIY'ers screw up the calibration of their torque wrench. Torque is based on the amount of force at a specific distance from the pivot. Without measuring the distance from pivot to scale placement, you will screw up the calibration.
@@matterofrights2344 agreed
If you're going to calibrate it this way, might as well throw away the clicker type and use a beam torque wrench, it'll be just as accurate.😆😅🤣😂
Interesting! I have a similar torque wrench, purchased in 1984 new for $25. I guess I should probably calibrate it. 🤪
Here in Glasgow I put my cycle into a cycling shop and had various problems with the pedal stem slipping off and being buggered. One day whilst my cycle was in the shop an engineer phoned me to tell be his wrench was calibrated against another and found to be off by quite a bit.
I have exactly the same model of torque wrench, after 3 years of very infrequent use of this wrench came out the result of 27 kg of the required 30 kg. I think it is pretty good for 3 years without calibration. Now at least I know how to get down to calibration ;)
did you apply the force on the center part of the handle and not the end
One thing to note: almost all scales are most accurate at their mid range, so they should be checked against multiple masses (the water). You would also want to use a scale that is smaller in range, since most mechanical scales are not accurate at the low and high sections.
Thanks, that's good to know!
Why not bypass the scale and mount wrench horizontally so the water jug can pull directly down? Seems like less pieces to throw off the calibration
@@lperea21 There are two things. First thing, the handle of the wrench should be 1m, which is not, but you can always compensate by measuring the water.
50Nm is roughly 5kg with 1m handle.
Fun part is when you have to make the wrench "stiffer", and then loosen the adjustment, so it'll snap on the 50Nm mark.
So, make a longer handle from a pipe, or some calculus with water, but I think it's more precise with that scale. Then you can actually see, what weight made it "snap".
Same goes to torque wrench itself.
A lot of almosts. Too many for my money, including mid range. All that matters is WHAT YOU HAVE. Maybe someone has a good scale, good fresh calibration showing it's deviance from true across it's entire scale. Take these lessons for what they're worth.
Thank you for this video. I always thought that as long as my lug nuts were consistent with each other that would be keep my rotors from warping. Being able to check my Harbour Freight wrench for accuracy is great.
Thanks for the important tip! I need to check my torque wrench out soon. I knew the calibration could be adjusted, but I didn't know how!
You're welcome and thanks for watching!
@@Carnold_YT You have a premium video. Great topic, great camera work, lighting & audio. Keep it going!
This was mega helpful and answered a question that was lingering in my mind. Thank you!
I think you would benefit on using a bow scale, since it locks in the peak weight, you could use that to help dial the torque wrench easier.
Most people don't know this but most things don't have to be at some super exact torque spec. There is a range and if something is in that range then it's fine. If there are multiple bolts then it's usually important that they are the same torque. So if you're within the torque range and all of your bolts in an area are tightened very equally at the same torque then it's usually okay. So if a torque wrench is off by like 1.5 lbs at a 60lb torque spec then it usually doesn't matter. Actually most things have a larger tolerable range than that.
If you're building a thousand horsepower engine then you should invest in an expensive, accurate, calibrated torque wrench though. Or if you're doing aerospace stuff.
Extremely helpful Arnold, had an old one like this for years and years but one time my young son got his hands on it and suddenly it was in pieces, I reassembled it but was never happy so just purchased a new digital one, had I seen your video sooner I could’ve saved a $150, so now armed with this new info it’s time to play with my old torque wrench😃, thanks for sharing Arnold.👍
As a sanity check, I've checked my adjustable torque wrench against a deflecting beam one coupling the drives together. I wouldn't calibrate my wrench this way, but have checked it for drift this way. It works great.
I really enjoyed this video, thank you!Another method for calibrating anything (torque wrenches today) is to compare two or better still three other wrenches. If you haven't got more than one perhaps borrow one and compare them and particularly if all three actuate the same that's pretty good test. You can also use the method of setting to an angle, clamp square drive in the vice, set up all wrenches to the same setting and with the angular unit note the angles that each wrench clicks. If they all break at the same angle you have three pretty good wrenches, if not you can self calibrate or get them checked by a calibration service. Especially good makes of mechanical ones are expensive to replace and worth the cost if in good condition. This method has proven to be pretty good over the years as I on several occasions had access to a proper test facility so was able to double check results.
Thanks for your comment and insightful tips!
I've thought about this too. I have a chinesium Click stop torque wrench and have wondered about accuracy. I don't have a scale so will use five gallons H20 to see if close. Also must allow for +/- Lbs. on wrench setting. Thanks for posting.
Thanks for watching William!
changing your grip affects the amount of torque you're applying at the head of the torque wrench, but it doesn't change the actual amount of force that has to be applied at the head to make it click. It changes the amount of force that has to be applied to the handle to make it click, but it still clicks based on the amount of torque being applied to the head/fastener regardless of how you're gripping it. so you can grip it at any spot and get the same results if you're just going by the click
It does change the reading (on the scale) of course. For instance ft-lbs is the amount of fource you would be pulling on the handle at a ft from the actual tip. So it does matter how far away the scale is on the handle, but i think you already understood that lol.
I guess another useful bit of info when doing the calibration is keeping the spring scale or water bottle etc. perpendicular to the torque wrench! Good tutorial. 😎
If you're going to calibrate it this way, might as well throw away the clicker type and use a beam torque wrench, it'll be just as accurate.😆😅🤣😂
Thank you very much for information, I didn't know this. I have one for more then 30 years for checking the wheel nuts. Good info.
Thank for watching!
When refurbishing the steering gear on my '67 F100 I needed a 7-10 inch-lb. torque wrench so I made one using a wooden dowel and a 1/2" carriage bolt with the head cut off to drive the socket. The tricky part is getting the value of a known weight to hang off the handle. (I think it was a 3/8" carriage bolt)
Smart thinking, if it works, it works!
I make a straight coupler, 1/4”, 3/8”, or 1/2” from two old sockets welded together. Annually, I couple my beam style torque wrenches to my click style clamped gently in the vice. I do three checks using a setting at the lower third of the scale, the center of the scale and the upper third. If the wrench clicks within 3% of the set torque across the board - good to go. If it doesn’t, I adjust the tension and retest until it passes. If it fails to adjust, it’s time for a new wrench. Beam style torque wrenches are non-adjustable and as long as they are not over torqued and bent/deformed, they are accurate in both directions.
Yes, beam style torque wrenches are super reliable, that's for sure!
This is exactly what I was going to post. Beam wrenches are always accurate, just not very user friendly in places where you can 't see the sale. So you always use them for calibration. One thing I haven't seen mentioned here is that accuracy is always a percentage of full scale. So a 100 lb ft wrench of + or - 2% means + or - 2 lb ft. If you have it set for 20 that's still 2 lb variance so 10% at that setting. Which is why you want to use a 25 lb ft wrench if you're trying to set 15-20 as a 100 can be waaay off.
Thank you so much for posting this! My old torque wrench has been unused for a few years and never calibrated since new. I need to replace head gaskets on my vehicle, and I was considering buying a new torque wrench. This just saved me a bundle! Thanks again!! BTW my wrench is identical to yours, except graduated in lb.ft., purchased at Princess Auto in Canada.
Are you shure? Normwise there are two tableaus... 180degrees around ☝️😉
Probably has newton metres as well.
Very nice to have a video showing how to calibrate these things. Thank you!
Thank you for watching!
Excellent to know. I used to work in mechanical measurement within precise Engineering. I never calibrated a torque wrench, somebody else always did them regularly! I used to calibrate mics tho.
Thank you for sharing. Very useful advice.
very helpful video. I had no idea that you could diy the calibration. now it makes sense
Nicely done! The principles of adjustment are pretty simple and you showed a straightforward way to accomplish your goal.
He accomplished something, but it wasn't accuracy,😆😅🤣😂
Excellent video! I have a couple of cheap torque wrenches myself with varying torque range values and I will definitely use this technique to check and calibrate them if needed. An average of +/- 5% of error is more than enough for your average backyard mechanic.
Great video.
Although you missed some of the best bits.
How did you calculate that 30 kg? At least a link to how to the calculation would have been handy.
How did you get the lock not off the handle. It was magically gone.
I would not have thought of doing this. Thanks for sharing
Davo's Shed, the torque wrench is set at 126 Nm. From Newton to kg, you have to divide by 9,81. That makes 12,8 kgm. Divide this value by the distance in meters from pivot point to where you apply the pulling force. In the video that is 42 cm, thus 0,42 m. 12,8 divided by 0,42 makes 30,6 kg.. To make it easier for yourself, put some painter's tape on the handle, make a mark at 42,8 cm and apply 30 kg of pulling force. Is more accurate.
@@chrisbode7173 very interesting!
That 9.8 is curious. Sounds like the good old metric system has something to do with that being acceleration due to gravity.
I better did out my old torque wrench. If I remember correctly mines not adjustable, it’s just the bending force on the handle.
It’s an oldie not a goodie. :)
@@DavoShed Correct, 9,81 m/s2 is the acceleration due to gravity. I've worked with torque wrenches based on the bending force of the handle. They give a better understanding of the torque phenomenon. Great!
thank you sir... this is very helpful for me because we have the same cheap torque wrench. God bless you sir
i think yu should do your tests at the middle of the handle (where the line is),not the very tip.Very good video though :)
Good information Thank You. It is always nice to know the true value of the torque wrench you are using.
Thanks for watching, I hope it was helpful!
I took a Herber Fraught $19.95 1/2" torque wrench to the calibration place here in town and paid my $60. It wasn't perfect or LINEAR by the scale, but it was with-in I think 8% across the board, which for a "clicker" (and automotive use) is "close enough" if you aren't building race engines. The WAY YOU use it will make MORE than an 8% difference. Like "just tighten and go" or "lube fastener, tighten, loosen, re-tighten to spec'd torque" or "tighten to spec, let sit an hour(2-4) loosen, re-torque" or whatever the procedure you are SUPPOSED to use. The $5500+ electronic wrenches are supposed to be calibrated (about a grand) YEARLY. If you're working on jet turbines or turbosuperchargers, you NEED that precision.
I found working on motorbikes where you get a steel bolt into a aluminum hole to be very careful as an oily well used bolt will easily strip the alu threads sticking to the recomended torque value..feel is everything . I think torque values are often given for a `dry `bolt also so reduce a bit if oiled .
That is correct, most workshop manuals don't state whether or not a bolt should be oiled. But applying a coat of oil will definitely affect the clamping force of the bolt (or nut). Especially with lightweight alloys, you should be careful. I personally like use my normal ratchet and tighten the bolts by feel in that case.
Wheel nut specs should typically be for dry threads, not for lubricated ones, except they add the info it's for lubricated threads
Its not often. ITS FOR DRY BOLTS unless specified otherwise. Never lube bolts, discard rusty ones and use new ones.
I thought this was a great video, thanks... I'll probably have to watch it a 100 times more before I really attempt it but it seemed very logical . Again thanks
I wonder how ambient temperature affects torque adjustment for these mechanical wrenches.
Two effects occur. One is that the rigidity modulus changes. For most materials this means they get less springy as heat rises. In the case of a torque wrench the actual torque drops compared to the displayed value on the handle scale.
Second is parts of the wrench physically expand as the heat rises and this also has the same effect as above.
Bedankt voor de tip. Ik wist eigenlijk niet dat je zo'n sleutel zelf kon kalibreren.
Voor een gelijkaardige momentsleutel heb ik in het verleden een omrekentabel gemaakt. 'Die waarde' instellen om 'dat moment' te krijgen, maar zo'n herkalibratie is natuurlijk minder gedoe tijdens gebruik.
I use another tq wr and a 15 mm 12 pt socket for 1/2 dr .
Which way do you turn to add or remove pounds of torque. clock wise = ?
Good video, very clever
I recently watched a video saying for spring-loaded torque wrenches in order to be absolutely accurate. They have to be “warmed up” first which means work them from 0 to maximum in steps of 10% and then back down the other way to put some heat in the spring and some heat in the grease internally
that’s clearly for high precision engine jobs and stuff like that.
for many years I used a deflection (beam) wrench. I figured that it was accurate if you could see the indicator, but with the way my eyes are now, it is tricky changing glasses.
@@TheFirstGhirn yes I’ve got two Warren and Brown deflection beam. Torque wrenches only way to go
Have been known to hold calibration for decades
Good video, what is the formula for leverage
I added the formula in the pinned comment. Thanks for watching!
@@Carnold_YT But you forgot to pin the comment.
I use your method on my cheapo one but my ancient airfitter's King Dick elbow torque wrench the only way is to replace the inner tension spring to calibrate and this thing is old old old but its pretty accurate still all these years on, very heavy too but cumbersome in you have to remove the end cap, use a spanner to wind the adjustor in and out, replace cap to see if its set correctly and so on as it is designed to be used all day long at certain torques. Apparently from what I have been told your airfitter or plane mechanic would have several setup and taped with different torque ratings on his trolley, then end of day the things unwound til next day when they would be wound back up to different torques, the elbow ensures perfect torque application thus you get very precise settings.
Having a beam style torque wrench is ideal for checking any other (affordable) torque wrenches. I mostly use it for lug nuts to ensure everyghing is tightened evenly.
Thanks for the update on the tools
Can you please explain the mathematics involved to determine how to calculate ?
I made a follow-up video where I explain the formula. It is very basic math, nothing complicated: ruclips.net/video/M-0LIaWKHO0/видео.html
@@Carnold_YT Thanks legend, I had a look at that video. Cheers 🍻 🍻 from Australia.
I thought the line between the knurls on the handle, marks the position where the torque wrench is calibrated. I wonder how much difference it would make, putting the scale on the very end of the handle (like you did), and on the calibration line.
You can apply the test force anywhere along the handle as long as you compensate for the position in your calculations. It's easiest if you select the distance to match the units you are using i.e. 1 ft from the pivot if using ft-lbs or 1 m if using kg-m.
It's ok to extend the handle with a lightweight rigid tube
@@paulg3336 center point of handle
@@paulg3336 they are designed center of handle for calibration. It will click at the same torgue with the force applied nearly anywhere after the pivot as the tube is stiff enough to react the forces without deflecting an appreciable amount. For calibration purposes, the center of applied force is assumed to be the center of the handle.
@@deanelewis5043 That is where you apply the force when you use the wrench.
To test the wrench:
*You can apply the test force anywhere along the handle as long as you compensate for the position in your calculations.*
Read what I wrote
The test force can be any weight at a suitable distance from the pivot to achieve the test torque
Good info. Never knew they could be calibrated (rarely use one).
Some say the torque reading is based on the smooth groove between the knurlings on the handle. That is where the scale should be pulling to calibrate?
Yes, that is correct.
I use a harbor Freight digital torque adapter and a socket that fits my lug nuts on the car. Set the adapter to hold a reading and use it on one of the lug nuts that in on my car's wheels with a torque wrench. When the torque wrench clicks I look at the reading on the digital adapter to see how close it is to the set point on the torque wrench.
That sounds like a handy device, what's the price of it?
Where was the spring scale hook placed on the torque wrench? Was it a calculated distance from the driver?
I measured the distance from the pivot to the end of the grip, hence I attached the scale hook on that point.
Great work. I would have wanted to see a bit more accurate calibration method but water in plastic container but I guess that's good enough for the scale used here.
And with the accuracy of the torque wrench in mind, I don't expect accuracy up to 1 nm, but I wanted to make sure that my wrench is in spec in the range I use most. Part 2 is coming soon!
I did use a calibrated torqwrench connected to (check) the other cheap torqwrench ,mij offset was 0,03 percent
verry happy ,most car workshops own a calibrated one and a checkup is easy to fix ,most mechanic are
willing help to test yours (for free ?)
Well damn, now I got to get a scale that has a hook. Thanks! Helpful info.
Use the water itself! The pull has to be at an exact 90* (perpendicular to handle) or there is a minor margin of error.
Hi, I wanted to do two tests after calibrating it: my key is small, 5 -25 nm, I set a weight of 2.6 kg at 20 cm that clicked at 5 nm and calibrate it. I wanted to do a new test with 4.6 kg at 20 cm result 9.1 nm but it doesn't click. I calibrate at 9.1 nm by loosening the spring tension but when I try the 5 nm again with the 2.6 kg from before it clicks much sooner. I recorded from the bottom dial. I don't have the same calibration for the various measurements.
I learned that it is important to 'work' a torque wrench before using it, or before calibrating it. It is basically a warming-up procedure: set the wrench to a low setting and 'tighten' a bolt, and let it click a few times. Then you raise the setting of the wrench and repeat it a couple of times. Once it is worked, you can start using or calibrating it. You should first test it across the range (from 5, 10, 15, 20 and 25 Nm) and then see where it deviates. I kept adjusting on low and high settings until I got an overall acceptable result. In this video I tried to adjust the torque wrench to be accurature in the range that I needed. Thanks for watching!
I would probably place the scale in the blank part of the knurled surface (in the middle of the grip).
That is the correct way to do it!
@@Carnold_YT and yet, you pull at the end of the grip on the black part. If you pulled at the narrow blank part, the force would probably be spot on.
Addition: I know all this is better than nothing (hopefully) and on a principle basis, but calibrating something at 5kg, and then use it at 30kg, is not exactly by the book either. But again, I understand the accessibility of a 5 liter can (I have several in the shed).
Other than that, great video! I've never checked my torque wrench, but perhaps I should.
PS. Keep up the good work with the Lexus - one of my dream cars!
Should you not be measuring at the middle of the grip where the smooth band is rather than towards the end?
I'll explain that in part 2!
how much did you turn while calibrating the wrench? i.e. what would be just rough adjustment to start with? and in which direction?
Very little actually, three quarters of a turn clockwise was enough to get it in spec.
Had no idea you could calibrate them, thanks for the video!
Very good video, in feet and pounds what is the math formula u used? Thanks
I used the good old formula: Torque = force x length of arm. Maybe you find this online calculator helpful: www.omnicalculator.com/physics/torque
Thanks for watching!
Could not see which way you were turning the inside but i now have the jist of it, i did not know you could calibrate them yourself I just assumed you could trust from the factory or do you have to do this every so often?
I check mine every time I do large maintenance. I don't expect it to be accurate over the entire range, but I want to make sure that it is accurate in the range I need for the task. That is what I check often.
Thanks for sharing. Reminds me that I need to calibrate my torque wrenches at some point.
Can i have the equation for working out the length to movement/weight
I explained the math in part 2 Dean, thanks for watching!
Force needs to be applied in the center of the hand grip. The handle pivots in front of the ratcheting head so the calculation from “center of the socket” to end of the handle is not correct.
That's a good remark, I'll mention it in part 2!
you are a great teacher and good videographer, thank you for the lesson
How come you didn’t tare the scale with the weight of the bottle before you put the liquid in it?
Great video, would have been interesting to see how accurate the maximum and minimum torque settings were after calibration at the mid point.
I have a follow-up video planned, to see how much my torque wrench deviates from the ISO standards.
How do you know which direction to turn the adjustment?
Turing the adjuster clockwise will increase the pressure on the click spring. This is what you do if the wrench clicks too early. If the wrench clicks too late (when it is overtightening), you have to loosen the set screw.
Great video and useful info - thanks for sharing
Advice for all. Always store your torque wrench in loose position, this way you don't need calibrate that often
Great video!
I looked up the math and found that 1 newton meter [N·m] = 0.1019716212978 kilogram-force meter [kgf·m]. So 126 N·m * 0.1019716212978 = 12.852 kgf·m. And since the distance from the applied force to the point of rotation is 42 cm or 0.42 m, 12.852 kgf·m / 0.42 m = 30.6 kg. So now I see how you arrived at 30kg of force.
One question - When your torque wrench was clicking at 25 kg, did you adjust the calibration clockwise or counter-clockwise to dial in the torque closer to 30 kg?
As a Canadian in my 50s I use a real mixture of imperial and metric. No question that metric is the superior system, though I still tend to think in terms of foot pounds because that's what my Dad passed on to me. 🙂
When the torque wrench clicked too early, I increased the pre-load on the spring, so it requires more force to click. To increase the pre-load, I turned the adjuster in (clockwise). I only took 3/4 of a turn to correct the pre-load.
I can relate to your story on mixed standards, I used to be a technical writer that's used to the metric system, but I have written many workshop manuals for the US and Canadian market. The conversions weren't the hardest part, I am so used to use a comma (,) as a decimal point, that I always needed to remind myself to use a point (.) instead. Anyways, thanks for watching!
I concur. Try going through the CMHC wood-frame builders handbook, you have to constantly convert everything from odd-ball mm sizes to 2x4 or whatever. I am not sure who in Ottawa thinks I head into Home Depot to buy a 1219mm x 2438mm sheet of anything. !
I talked to a guy once who pointed out that the romans split the inch into 16ths and that 12ths were superior because you could more easily divide them. This in turn points out the problem with the metric system which is fractions are hard when all you can divide evenly are 1, 2, 5, and 10. Now... if you live in a metric world do you still buy a dozen eggs or are there only 10 in the carton :)
@@danielboughton3624 Hmmm? I saw eggs in Canada sold in 6,12, 18 and 30 eggs per carton.
@@danielboughton3624 In Australia , 12 or 6 pack
I would think the accurately of scale would be a factor that being said good job
Great video, great presentation. Thanks so much
Thanks for watching!
in my opinion you should apply a scale hutch on the middle of grooved place because right nowyou use it differently than normal. your hand should have grip around a center of hand position not far away in the end. so maybe originally near 30 was good.
Apparently you do not understand how a torque wrench works.
@@deepcangler they work on force needed to slip mechanical part tensioned by spring. Because this is measure in Nm usually it's mean that force attached to the arm it's correlated another force in fixed arm and fixed slip, resistance. So if you change length of the arm with the same force you change torque. So if you calibrate torque you should apply force the same place. Later after calibration it's not important when you put force as soon you exceeded torque it clik or slip. But with calibration it's one of the most important...
Nice job and great instructional video!...but I prefer to call such tools a Torque Gauge! because every wrench is a torque wrench, because it applies torque, but a Torque Gauge measures it (or in the case of the click type, even limits it). Cheers from my garage to yours!
Thanks so much for your comment, I think your terminology might be indeed more correct than calling it a torque wrench.
My dad worked on aircraft in the 50s and 60s then testbeds in the 70s. I need to use a torque wrench but somehow his arm is amazingly precise he knows exactly what 100nm feels like to within 5nm. On top of that, he ended up in technical publications where the torque settings were decided and its a mixture of finger in the wind mixed with measuring what an engineer thought felt was right. The exception was torque to yield but thats a completely different thing. He still maimtains you only need a torque wrench to get consistency for people who don't understand what they are doing. I can't feel 100nm from 200nm. Obviously 200 is twice but when you cant get square on something or your arm at a funny angle I just can do it... he still can.
Thanks for sharing that story James. I completely agree with your dad, I've been a technical writer for over 20 years now and determining torque values for workshop manuals is often done by what experienced mechanics feel what is right. If we needed a torque value, we just measured the breakout torque and went with that. As I said in the start of this video: I like to work by feel an in my opinion any good mechanic can do that. On safety critical components, high torque connections and in the aerospace industry, it is a whole different story. That's where the calibrated and certified stuff comes in. But then again, in my day job I see a lot of overtightened bolts that just snapped off because the recently calibrated (they're always recently calibrated when stuff happens) beeped when the set torque value was long exceeded.
Your Father had the 'calibrated arm', as we used to say in the Aircraft sector.
The old German torque of 'Guden' Tite' was the other expression we would jokingly use.
On aircraft (there is no Parking Garage in the sky) - it is ILLEGAL for a mechanic to tighten a nut or bolt which has a called out torque - and not to use a certified Torque Wrench. You must sign documents attesting to your work when finished. Crud - the FAA will fine a mechanic - if they come to a shop or Airline; and find an individual working on an Aircraft without the Documents and drawings stating what to do and how to do it - at his location and readily available.
If I don't have a fancy spring scale to pull on would a cheap digital luggage scale work and possibly be more accurate across its range than your water calibrated spring scale?
I'm pretty sure it will work just as good, or even better.
@@Carnold_YT it certainly wouldn't look as good as yours does in the video. I'm going to test an over 50yo snapon dial torque wrench or as the dial reads 'torq meter"
Thank you for not hitting me in the head, and also for the well presented instructions.
First: of all it is a factor of 9.81, secondly: the center of the handle is used as the touchdown point, you have a special groove milled there
I adressed that in part 2 of this video, and indeed: you are right. Thanks for watching!
is it necessary to add weight of water container
Not really, it only adds a few grams.