How To Calibrate A Torque Wrench In Two Ways

Every car owner and homeowners need a torque wrench. You will never know when you will need to fasten some bolt or nut in your car and doing this manually is just impossible. Unless you have the strength of the Hulk or Superman then maybe, you can do it with your bare hands. But realistically, you will need a special tool for that.

Today you will learn how to calibrate a torque wrench.


This particular would require some adjustment on your end but don't worry, with the right instructions, you will be able to figure it out. Others hire a professional to calibrate their torque wrench but I'm more into independence, which is why I'd rather do it myself. You must calibrate your torque wrench on an annual basis to ensure its quality and accuracy.

Before we move on, you must know that there are two ways on how to calibrate a torque wrench. One is through weight calibration and the other is called a fish scale calibration because you will need a fish scale tool for it.

Let us Start with Weight Calibration.

Method 1​

Materials That You Need

  • Torque wrench
  • Pen for marking (I suggest a sharpie)
  • Calculator

1. Marking:

Take your torque and make sure that you mark the center of its drive located at the back.

2. Measuring:


Take a look at the wrench and know where do you think you would comfortably place your hand as you use it. From there, measure that area and create a second mark on that place. Make sure that you know exactly how apart the distance of those two marks you just created.

3. Securing:


Tighten the square head using a bench vise. Keep in mind that there shouldn't be any part of the wrench would touch that vise except the square head. You can them locate the handle using a horizontal position.

4. Computation:

Now, this part might require some of your math skills. You will need to line up the value of the torque to the marks of the two distances you created in step 2. You will need to multiply that by 20 pounds or 9.07 in kilograms.

5. Dangling:

This sounds fun but really, this part is kind of where it gets serious. You will need to dangle the weight of the torque from the marks that you made earlier.

6. Listening:


After doing that, you will need to listen to the tool and wait for that click to be heard. Once you heard the click, it is now time that you lift the torque's weight and slowly places it to the head of the wrench. Do it until you stop hearing the click.

7. Marking Again:

Make some marks again just to guarantee you of the spots being right. Note that if you didn't hear a click the first time, you have to place the weight a little bit far from the head of the wrench and do it until you hear that clicking sound. It is safe to do the markings by doing this step twice.

8. Calculation:


Count the distance that you created from the square head to the click marks that you made. Remember that distant count and multiply it by 20 pounds or 9.07 kilograms. The exact formula here is Ta=Ts x(D1/D2). The Ta stands for the torque setting, while the D1 is for the distance you found on your first marking and the D2 for your last

9. Checking:

You will need to go over the calculation again just so you are sure that you got the right calibration. Remember that the most important thing here is the distance that can be found from the center of the drive head.

That is where you usually hang the weight and not where you put your hand. People often make that mistake, which is really confusing if I don't stress that out here.

Next stop, we have the Fish Scale Calibration. I have to say that this method is by far, the easiest! I highly recommend that you use this but it is also handy that you know how to deal with the weight calibration.

Moving on, here is how to calibrate a torque wrench using this fish scale method.

Method 2

Materials That You Need

  • Fish scale
  • Vise
  • Torque
  • Wrench
  • Calculator
  • Pen for marking

1. Securing:


Get a vise and start securing the wrench drive in it.

2. Fish Scale:

This is the part where you will need a fish scale to be attached at least one foot located at the center of the drive.

3. Measuring:

Know the weight of the pull that is on the scale to determine the exact setting for the wrench. After that, you can secure the wrench back in the vise.

4. Calculating:

Get a calculator to count the error in percentage. Repeat steps 1 to 3 by using various wrench settings and check the consistency of the error that is appearing.

5. Final Task:

Add the percentage error to the amount of scale that is on the wrench.

Visual learners could also learn from this tutorial video. Watch it from the link below.


It may sound intimidating at first to learn how to calibrate a torque wrench but with enough practice, you will get the hang of it and probably could do it professionally. You will be surprised on how much some people would pay you just to calibrate their tools.

This skill comes in handy, especially if you are stranded in the middle of nowhere and you need to fasten some bolts in your car.

The steps are pretty easy but it is understandable if you get lost from the whole calculation procedures for your first couple of tries. Trust me, that is not unheard of and you won’t be the only one who struggled with that in the beginning.

But don’t shy away from learning it and I’m sure that you will be able to calibrate it on your own. Cheers to independence and learning new things! Make sure that you always keep this tool in your tool kit wherever you go, so you know what to do in case of emergencies.


About the Author

I am David Walker ,I'm a car enthusiast. Through this blog, I want to share every single experience I had with my beloved car with you guys. Definitely feel free to comment, give feedbacks and show us what You and your cars have been through.

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