How to calibrate a (cheap) torque wrench
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- Опубликовано: 30 янв 2023
- Now that I'm in the middle of working on the brakes and suspension of my #Lexus #LS400 , I want to be sure that these parts won't fall of. Usually I work by feel and rely on experience, but just to be sure I want to tighten important bolts to spec. Now, I have this cheap torque wrench that I've been using for years, but I never really checked or calibrated it.
To make sure that I torque these safety-critical components to spec, I'm calibrating my trusty old torque wrench. In this video I show you how it's done.
PLEASE NOTE: This is not a certified method you should use for customer work, but it's good enough for home mechanics and hobby projects. And for government work.
To buy me a coffee: www.buymeacoffee.com/arnoldsr... 
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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?😂
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?
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!
That is exactly the type of torque wrench I have, so for me this instruction was perfect!
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.
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
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
wow. This is the first time I've ever heard about this kind of a wrench.
This was mega helpful and answered a question that was lingering in my mind. Thank you!
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!
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. 😉
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.👍
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,😆😅🤣😂
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.
Thanks for that useful information. Now I can check the accuracy of my torque wrench without fancy equipment.
Very nice to have a video showing how to calibrate these things. Thank you!
Thank you for watching!
Thank you for sharing. Very useful advice.
you are a great teacher and good videographer, thank you for the lesson
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.
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 the update on the tools
Thank you very much for demonstrating how to calibrate those "cheap" torque wrenches!!!!
Well damn, now I got to get a scale that has a hook. Thanks! Helpful info.
very helpful video. I had no idea that you could diy the calibration. now it makes sense
Arnold, very reasonable accuracy for this job! Thanks for the video.
Thanks for watching Karel!
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.
Great video and useful info - thanks for sharing
Nicely done! Thank you!
A very useful video-thank you.
thank you sir... this is very helpful for me because we have the same cheap torque wrench. God bless you sir
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.😆😅🤣😂
Thank you for this! I have been wondering how to do this!
Had no idea you could calibrate them, thanks for the video!
Great video, great presentation. Thanks so much
Thanks for watching!
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.
Thank you! This is very helpful
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.
Thanks for sharing. Reminds me that I need to calibrate my torque wrenches at some point.
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!
Good info. Never knew they could be calibrated (rarely use one).
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_
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.
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.
Thanks for the video! 😃
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
Interesting! I have a similar torque wrench, purchased in 1984 new for $25. I guess I should probably calibrate it. 🤪
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.
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!
Wonderful tutorial, bedankt!
You're welcome!
Great video because I’ve got the same wrench! Top 👍👏👊
Great video!!
nice video, thank you
very handy information here
Great vid. Didnt know this was possible.
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!
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.
Great video=)
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!
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
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.
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.😆😅🤣😂
Awesome 👏👏👏
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.
I will do this to my torque wrench asap. Tnx.
1 gallon of water = 8 pounds. 1 pint of water = 1 pound. "A pints a pound the world around". 16 pints in 1 gallon. Great video! This is the first video I've seen on this topic. Thanks.
One gallon of water is 8.33 pounds.
@@robertheinkel6225 or 1 liter of water weighs 1 kg (2.2lbs)
Advice for all. Always store your torque wrench in loose position, this way you don't need calibrate that often
Thank you 👍
thank you
I think it’s funny everyone arguing about how to unwind it and at what angle to use it but nobody seams to mention that this is being measured as if one uses only one finger at the very end of the handle. There’s likely a 2-3 inch difference in center pressure when using your whole hand.
Lighten up, consistency is often as important as torque value.
Thank you!
You're welcome!
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.
@@DanielNotDeadYetThomas yes I’ve got two Warren and Brown deflection beam. Torque wrenches only way to go
Have been known to hold calibration for decades
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.
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.
Thanks.
Thanks for a very informative Video, as others Mentioned didn't realize you could adjust. The Big Brains always Muck up the Topic.
Thanks for watching!
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!
Evidently you've watched a few This Old Tony videos. LOL
Love it 😁
Outstanding presentation! I never knew how to calibrate them. Thank you.
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.
Good to know.
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
Smart!
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 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.
Thank you for not hitting me in the head, and also for the well presented instructions.
Nice.
simple cool
WHEN I WAS IN COLLEGE GETTING MY ELECTRICAL/COMPUTOR ENGINEERING DEGREE. MY PROFESSOR WAS THE ONE WHO FROZE THE ELECTRONS IN A WIRE FOR NASA. DURING ONE OF HIS CLASSES. TOLD THE CLASS HIS FRIEND WAS A ENGINEER WHO DESIGNED SPRINGS. MY PROFESSOR SAID YOU WOULDN'T BELIEVE THE ENGINEERING THAT GOES INTO DESIGNING SPRINGS.
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.
Great to know how to calibrate or check the torque wrench. Thanks for the video. Now where do I find that giant scale :)
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!
ToT style much😉.... Good video thanks
Well…“exactly“ 30 is exactly wrong… more like 30.59kg since a kilogramm does NOT apply 10N of force but about 9.81
ALWAYS undo your torque wrench when not in use as the internal spring can "take a set" and go out of calibration...
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 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.
Yes, I have used the water method. Litre of water is so close to one kilo error is insignificant
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.