Between the digital vs manual torque wrench, which one should you buy?
These two tools do the same job – they tighten fasteners and they measure the torque applied. Still, even from their design alone, they are completely different.
Don’t let the terms digital and manual confuse you. These just mean the way that the tools measure torque.
When the digital, also called the electronic torque wrench reaches the set torque, it gives a buzz, vibration or flashes a light.
When the manual, also called click torque wrench attains the desired torque level, it gives an audible click so you can stop tightening your fasteners.
In some aspects, these tools work in the same way because your body weight is the source of power when you are tightening lug nuts or other fasteners.
Main differences between Digital vs Manual Torque wrench
If you are in a hurry, here is a table giving a sneak peek of their outstanding differences:
Manual Torque Wrench |
Digital Torque Wrench |
| They have a mechanical scale for measuring torque | They measure torque using strain gauge technology |
| You have to twist or slide the handle to set torque | Has preset torque levels – just enter your numbers |
| You only get a click signal when you get to desired torque | It gives a sound, vibration or flash when set torque is reached |
| Can be difficult for beginners to set torque and use | Easy to use for users with no experience |
| Cheap to buy and they don’t require a battery to operate | Costs more to buy and they use a battery to operate |
How does a manual torque wrench work?
If you have been using a manual type torque wrench for your bicycle repairs, you may have wondered how it actually works.
It is really simple.
The main parts of a manual torque wrench
First, there is the handle where you apply force (from your body weight using your hands) to tighten fasteners.
Secondly, there is the head, which can be round, square or teardrop/pear in shape. The head also has something that we call the drive, which is a square head or knob.
Some manual wrenches come with a hex-style drive, so do not be alarmed. The drive is the connector between the wrench and the socket.
The socket (which may or may not be supplied with the torque wrench) goes on the fastener. On the drive, we may have a safety mechanism referred to as the spring-loaded ball detent system.
It holds the socket and it will not release it until you press a button, designed for that.
Mechanical clutch
The head of the wrench (socket and all) is attached to a long beam (which also has a small mechanical clutch), which is contained in the outer handle.
The outer handle is also attached to the head of the wrench at a given pivot point. It is cylindrical in shape and so the beam attaching to the head is contained in this handle.
Compression spring
This beam is farther connected to a spring. The work of the spring is to apply compression to the clutch. At the end of the wrench handle, there is a dial, whose work is to adjust the compression of the spring.
The more compression you create in the spring to set the torque (the recommended fastener tightening force), the more force it will take to disengage the mechanical clutch from the inner beam.
When you set the torque, you have to twist the handle. The handle then applies a calibrated amount of tension to the spring, equal to the torque (force) you have set.
As you continue tightening your fastener, the clutch prevents the inner beam from slipping off the pivot point (where the outer handle cylinder is attached to the inner beam, it is a pivot, so it can move/swing). It will hold but as the force builds up (as you continue tightening), it cannot hold anymore.
So, it slips, and swings/rotates at the pivot point.
When this happens, the inner beam hits the cylindrical handle, so you hear the click, which alerts you that you have attained the set torque and you can stop tightening the fastener.
What is a digital torque wrench and how does it work?
Many people ask, are digital torque wrenches worth it? They are, 100 percent, to people who want to have it easy.
Usually, if you already have a manual torque wrench, you need not get an electronic one. Despite the different mechanisms, the result is the same.
This torque wrench looks like a manual wrench. However, along the shaft, there is a small LCD or LED display with buttons on the side for entering your torque settings. This type of wrench uses batteries, which can run low and need replacement.
Because of the ease of use, all that you need to do is to find out the specified torque for the fastener that you want to tighten.
You should then set the torque value of the fastener on the display screen. After that, attach the socket and commence tightening the fastener.
Stop tightening as soon as you hear a buzz, feel a vibration or see a flash of light.
Do digital torque wrenches need to be calibrated?
All types of torque wrenches, including electric types, need to be calibrated so that they can apply precise force on nuts and bolts. Even an electronic torque wrench requires to be calibrated.
Because of the sophisticated design of the electronic torque wrenches, most people think that these tools do not lose their calibration.
Others think that the tool self-calibrates after every use. However, this is not true at all.
If you drop this torque wrench on the floor, it will lose calibration. The same can also happen when you hit it against, or with something.
Even if all these do not happen to the digital-type torque wrench, the general recommendation is to calibrate a torque wrench once every 1000 to 5000 cycles, or once in 12 months.
Torque-sensitive fasteners in the engine bay, spark plugs and other parts require to be torqued to the recommended torque.
However, if you are using an electronic torque wrench that has lost its calibration, you can get false torque readings. Imagine the wrench showing that the fastener is torqued to 150 ft-lb, when in reality it is only torqued to 130 ft-lb.
When the torque wrench has not lost its calibration, it will self-calibrate when you switch it on, so that you can use it.
Sometimes, you might switch on your torque wrench and it will display an error reading. If this happens, most of the electronic torque wrenches just require you to place them on a flat surface for a few seconds and they right themselves.
Please note that this form of self-calibration does not mean you should not take it for laboratory or expert calibration in the due time.
Digital vs Manual Torque Wrench: Main Differences
If you looked at the table that we used in the second section of this post, you know there are some outstanding differences between manual vs digital torque wrenches.
The way they work
The manual or click torque wrench works in a very mechanical way. When you twist the handle to set the torque value, there is compression inside the handle.
As you tighten the fastener, the spring compression increases. When you reach the set torque/force, it clicks. (please check the third section of this post).
The electronic torque wrench on the other hand is simpler to use. It uses batteries and once you switch it on, it self-calibrates in 2 seconds.
You can then enter your torque value using the buttons provided for that. You can then commence tightening the fastener and when you reach the final torque, you will hear a buzzer, feel vibration or see a flash.
Ease of use
Here, the electronic torque wrench takes the award. They do not come any more plug n play than this one.
Everything about it is so simple, including setting the torque. The torque readout is also hard to miss even when you are using the wrench in a noisy place. If you do not get the buzzer, you cannot miss the flash of light or the vibration alert.
On the other hand, the manual style torque wrench has a longer learning curve. You must first learn how to set the torque before you can use it. This requires twisting the handle to match the torque value you want.
Durability
Generally, a click torque wrench will not last as long as a digital one. If you take good care of it, it can last through many frequent uses.
The manual wrench is more vulnerable because of the delicate spring mechanism. However, it is cheaper so that compensates for the short durability.
Torque accuracy
The accuracy rating of the different wrenches is more or less the same. However, because the electronic torque wrench is too sensitive, it is easier for it to lose its accuracy, faster than the click-type one.
If you drop it or hit it against something, the accuracy will be affected. If you use it repeatedly, its accuracy can suffer.
Please note that even the manual torque wrench also requires careful handling. Mishandling it can make it lose its calibration.
Torque readout
The two types of torque wrenches are different in the way they give their torque readout. The electronic one is better because it displays real-time torque on the display, in large numbers so you can read easily.
It also gives other alerts such as a buzzer, a flash of light or vibration. Besides, it will hold torque for 15 seconds so there is no risk of under-tightening your fasteners.
Which is better between manual vs digital torque wrench?
If you are a professional mechanic, you will need many types of tools, including varied torque wrenches.
For trucks and big machinery, a pneumatic torque wrench is appropriate. For cars and smaller trucks, get a manual or electronic torque wrench, or both!
The click type torque wrench is more affordable, with some of the very best brands costing about $40. Digital ones are costlier, but they give great value for money because of ease of use, durability and quality of work.
If you are asked to choose between these two tools, choose the electronic one. It is more stylish and it measures torque in as many as five different units while the manual one mostly does three units.
Wrapping Up
If you get the click torque wrench, you will get a good deal. A digital torque wrench will give you a better deal though.
What you get between the two generally boils down to your budget and preference. Some people just prefer digital tools because of their ease of use. Others feel more in control when they use a manual tool.
Remember, you still have to get the sockets that you will use with the two tools. Therefore, between digital vs manual torque wrench, get the one that suits your budget in the best way possible.
For faster work, get the digital one. If you are new to tools and you would like to remove the guesswork out of the picture, get the digital one.