How to calibrate a (cheap) torque wrench 

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.

BEST comment!

It would have been good to use lbs

Why?

True. But which colour you recommend for the socks?😂

Thanks for watching Roger!

🙈

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?

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.

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.

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

Arnie is not a Dutchman, clever cloggs. 😉

He accomplished something, but it wasn't accuracy,😆😅🤣😂

Thanks for watching Karel!

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_

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.😆😅🤣😂

Are you shure? Normwise there are two tableaus... 180degrees around ☝️😉

Probably has newton metres as well.

You're welcome and thanks for watching!

@@Carnold_YT You have a premium video. Great topic, great camera work, lighting & audio. Keep it going!

Thank for watching!

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.

Thanks for watching, I hope it was helpful!

did you apply the force on the center part of the handle and not the end

Thanks for watching!

Exactly. This video is all wrong!

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.😆😅🤣😂

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

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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Fwfnf06dl84.html

One gallon of water is 8.33 pounds.

@@robertheinkel6225 or 1 liter of water weighs 1 kg (2.2lbs)

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.

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 watching William!

Thanks for watching!

same here bro..Ive got a dirt cheap ,as in 10 dollar 1/2 drive one new from harbor frieght that Im always leary of.. i'd like to check it and calibrate...nothing like trusting ur torque wrench, tightening and waiting for the click and it doesnt happen, so u end up stripping the bolt... mine looks almost exactly like the one in this vid

126Nm is 12.8Kg with 1m handle, so with 42cm handle it's 12.8 x 100 / 42 = 30.47Kg Simple math.

@@Njazmo Awesome, Thank you. Really is, thought it would be more than that

Great video, thanks!

Thanks for your comment and insightful tips!

If your torque wrench clicks too early, say at 26 kilo of force, the pre-tension on the spring should be increased. Half a turn clockwise of the adjustment screw is usually enough to correct the pre-tension. I'll adress this in the next video. Thanks for watching Troy!

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.

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.

You're welcome!

Yeah, sorry about that - I must admit I am a big fan of Old Tony.

@@Carnold_YT no need to feel sorry. I like this style. And i'm a fan of ToT, too🍻😁

Thanks for the info! Regarding your question: the spring load adjuster only has a small lock screw on the side. It cannot be adjusted without removing the grip. Thanks for watching!

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 have a follow-up video planned, to see how much my torque wrench deviates from the ISO standards.

Smart thinking, if it works, it works!

You're welcome!

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!