As you might know that a torque wrench is a long-armed socket-like wrench that contains an indicator to tell when to stop. To ensure its safety, it is essential to calibrate the wrench appropriately.
So, if you work in engineering, field service, production, or simply a lover to do everything on your own, you can read this article on how to adjust a torque wrench and test it by yourself.
Let’s get started.
Why Do You Need To Test Torque Wrench?
Manufacturers dedicate an appropriate amount of torque for all fasteners, like nuts, bolts. If a fastener is under-tight, then it cannot give thread loading, on the other hand, one may damage or break the fastener because of overtightening. And in the case of a scope torque wrench, you have to be extra careful.
To do the task perfectly, it is suggested to test the reading of your torque wrench periodically. For this, you can go to a professional mechanic lab or test at home.
How to Adjust a Torque Wrench
You should follow the following steps to test your torque wrench easily:
Step 1: Writing Down the Measurements
If you are calibrating the wrench for the first time, then here is an advice that you should always follow. You should always start measuring from the middle of the screw drive, the point where you put in the socket.
For the matter of simplicity, it is good to use discreet inches rather than fractions. Then use any marker to mark the point on the handle. You might want to write it on a paper for your future reference. Generally, the torque wrenches are 24 inches (61 cm) in length.
Step 2: Placing the Torque Wrench
The 2nd step of the process works properly if you happen to get a vise in which you can secure the torque wrench. But don’t worry. If you don’t happen to have a vise, then you can use a socket. First, place a socket on the wrench and secure it. Place the wrench on a lug nut that belongs to any equipment.
The test is designed for a vertical room because you need to add the cord and weight as well to calibrate the torque wrench.
Now, you have to place the end of the torque wrench, which is square in the given vise – or in a lug nut (if you don’t have a vise.) if you are not using a vise, then careful with tightening, because overtightening can cause damage.
You have to place the handle facing outside; otherwise, it will create a problem for the cable and load. While performing, you need to make sure that only the square drive is connected in the vise, because the handle needs to move smoothly.
In case you are not using a vise, you should put a piece of cardboard behind the torque wrench to avoid damage. Because the equipment can be damaged because of the load. For your safety, wear boots or steel-toe in case anything slips.
Step 3: Perform the Calculation
Our main task is to figure the perfect measurement for the torque wrench. For that, you have to increase the length you noted in step 2 by the weight that you are going to hang vise (in this case, 20 pounds (9.1 kg)).
The result is 480-inch pounds (24 inches * 20 pounds) = 40-foot pounds.
Before calculating the numbers, be sure that the length and weight are in the correct form.
Your figures will be a different one if you happen to use a wrench of different lengths and weight. But the equation will always be (handle length * weight) / 12.
Step 4: Place Weight To Check
To complete the calibration test, bind the rope around the set weight and then prepare a loop on the other side. The loop must be large because it has to move around the wrench handle. A
Also, you need to assure that the weight is not placed so low that it will contact the land.
Then, fix the torque of the wrench at 25 foot-pounds.
If you can recall, we have marked on the 24 inches in the first step. So, now hang down the loop on the torque wrench to defer the weight.
If you listen to a single click by the weight you put, then fix the weight to 26 foot-pounds. But if it does not click, it means the weight is accurate for your wrench.
If it clicked as ours, you need to follow the last step that will explain how you will adjust torque wrench.
Step 5: Adjusting Your Torque Wrench
You have completed most of the steps of testing your torque wrench.
For adjustment, you may easily do that by tightening the tension spring.
You can find them in the center of the torque wrench, or if not there, you may find those under the handle, but it will cause a bit of more work.
You may need to alter the measurements to adjust with the attached weight. It will only require if the mark that you set is placed on the set where screws are placed.
But make sure that the torque wrench is fixed to the previous setting of foot-pounds because you performed this calculation in Step 3.
As like before, now hang down the ring end of the cord with the stress. It has to be on the mark that you noted in Step 1. (The mark will be a different one if you happen to have removed the handlebar to set the setting of the screw.)
If you can’t hear the click this time also, then you are advised to set the weight apart and strengthen the screw in the clockwise direction by a small amount.
Now place the weight on the marked position of the torque wrench on the loop end of the rope.
If you get the click, then this process is done for you. Your torque wrench is now adjusted. But if you cannot hear, then repeat the process till you can hear the click.
So, finally, hearing the click, you can take off the weight and then attach the handle (in case if you had it removed it for the adjustment process).
The above technique is one for you to do it by yourself. If you find it difficult, we have another option for you that is an easy one. And that is a digital device to test your torque wrench.
How To Use Torque Analyzer
This is an easy digital device to use. The monitor shows a feature that lets the person know whether the torque wrench is precisely calibrated or not.
Also, it has some analyzer components that allow you to attach with numerous external sensors. It also has different operating modes that allow you to perform tests on different tools at a time. The tool becomes more useful, when you are working with a digital torque wrench.
This device is a lot like a smartphone. So, it will be easy for you if you have a smartphone. This device allows for some testers to sit on any surface, but the other ones should be placed on a fixed surface like the surface of a workbench.
Here are the steps on how you can test your torque wrench digitally:
- The screen of the analyzer has a menu screen displaying options, like “Units,” “Quick Test,” “Setup,” and “Filter, “Mode.”
- Place the torque wrench into the input of your digital analyzer.
- That movement is transferred to the indicator, which is placed on the maximum torque reading until someone sets it to zero.
- Now, the machine will compare the reading on the scale that is placed on the wrench with the one on the tester.
- There is a detailed manual on how you can calibrate the torque wrench by using a digital device.
- And finally, the analyzer will give a reading that will indicate whether your torque wrench needs calibration. This device also allows you to quickly upload this reading to your computer.
So, now you have learned about the easy ways of adjusting your torque wrench. If you still find it difficult, then you can send it to professionals.
It is very important to test regularly that your torque wrench is giving an accurate reading. It is suggested to note down how often it is used and how many hours it works. You should also note down how many cycles it is completing. and it’s also important to know how to test torque wrench properly.
Rule of thumb is to test it after a torque wrench has completed around 100,000 cycles. To avoid it from damage, we suggest you keep it in a clean and dry place. If you see any damaging sign, don’t hesitate to send it over for servicing.