Success usually comes to those who are too busy to be looking for it.Henry David Thoreau

How a Torque Wrench Works?

How a Torque Wrench Works?

If you’re a car enthusiast, then you know the importance of a torque wrench. This little tool is responsible for keeping your car’s engine in good condition by ensuring that all the bolts are properly tightened. However, how does it work? In this blog post, a few torque wrench experts will take a closer look at how a torque wrench works and discuss some of its key features. They will also provide tips on how to use it correctly!

What is a Torque Wrench?

A torque wrench is a tool for tightening screws and bolts to a precise torque level. Fasteners may be tightened to the proper tension with this device, which helps prevent damage from over-tightening or joints coming apart as a result of under-tightening.

This implies that ensuring equipment safety, assembly, and performance is dependent on applying the correct torque measurement. Conrad Bahr developed these tools in 1918[1].

There are two main types of torque wrenches: digital and beam.

What is a Torque Wrench?

Digital torque wrenches usually have an electronic display that measures the amount of torque being applied, while a beam-type wrench uses a calibrated gauge on the beam to indicate when the desired level of torque has been reached.

What is Torque?

It is the measure of how much a force on an object causes it to rotate, as determined by the pivot point.

Torque is measured in pounds-foot (pound-foot), pound-inch (pound inch), or newton meters (newton meter).

The basic formula for torque is Torque = Force x Distance from the pivot point or T=Fxd [2].

Where T is the torque in pound-foot (or newton meters), F is the force in pounds (or newtons), and d is the distance from the pivot point to where the force is applied in feet (or meters).

For example, if a 100-pound weight was hanging at a distance of two feet from a pivot point, then the torque would be 200 pound-feet.

What is Torque?

Should You Use A Torque Wrench:


  • Prevents over-tightening of bolts and screws which can cause damage;
  • Ensures components are tightened to the manufacturer’s specifications;
  • Can prolong the life of a component by preventing fatigue failures caused by over-tightening;


  • Can be difficult to use in tight spaces;
  • Requires some practice to use correctly;

So, whether you’re a professional mechanic or just someone who likes to do their own repairs around the house, using a torque wrench is always a good idea. They can be a little tricky to get used to at first, but with a little practice, they are easy to use and can save you from damaging your components.

What are Torque Wrenches Used for?

The torque wrench has one single purpose: to tighten nuts and bolts. However, it does so in a very specific way that adds value for both professional mechanics and casual home users alike.

Whenever you tighten a nut or bolt with a hand wrench, you can turn the handle as much as your strength allows until the fastener is tight enough. That’s pretty easy.

However, what if there was some kind of fastener that requires more than just “tight enough”? What if tightening it too much could actually damage it? Some nuts and bolts are made out of extra-strong materials like steel alloys or hardened steels, but they only have so much resistance before they break under pressure or deformation (like bending) [3].

What are Torque Wrenches Used for?

This is where the torque wrench comes in. It measures how much twisting force you are applying to a fastener and stops you from applying any more once it reaches the pre-determined level of torque (the amount of rotational force). This prevents over-tightening and therefore damage to the nut or bolt, as well as ensures that they’re tightened to the correct specification for the job at hand.

How Different Torque Wrenches Work:

1) Beam

The beam torque wrench is the oldest type of torque wrench on the market, and it’s also one of the easiest to use. It uses a simple lever system that allows you to measure how much force you are applying as you turn a nut or bolt with an attached handle.

The scale on this tool is engraved into its body in foot-pounds (ft-lbs) or inch-pounds (in-lbs), and it can be set from 0 – 100 ft-lbs.

Using a beam torque wrench only requires reading off the scale when your target fastener has reached its level of torque. There’s no need to reset the tool after each use, and you can even use it as a regular hand wrench if needed (just be sure not to exceed the torque limit).

The downsides of using a beam torque wrench are that they can be inaccurate if not calibrated properly and they require more physical effort than some other types of torque wrenches.


2) Click

The click-type torque wrench is one of the most common types on the market, and it’s also one of the easiest to understand. It requires no calibration or special setup; you just turn a nut or bolt with an attached handle until you hear a “click” sound indicating that your target fastener has reached its level of torque.

Click type wrenches can be set from 0-50 ft-lbs.

Using this tool only takes place in two steps:

  • setting up for use (which involves turning a dial);
  • tightening nuts/bolts until they reach their specific levels of torque (this step usually involves keeping track via sight);

When using this tool, there are some things to keep in mind like how hard it may be for some people to hear the “click” sound over other noises in their environment and also not applying too much force after hearing this noise because there could still be some torque left before reaching your target level (over-tightening).

The downsides of using a click-type wrench are that they can break if used incorrectly or with extreme force, which means you will need to purchase another one. They require regular maintenance like cleaning out dirt buildup inside its body and checking calibration at least once per year.

It’s important to note that all click style wrenches must have an external tension spring release mechanism so you don’t apply excessive torque when trying to use them past their maximum limits. This type of wrench will usually have a red band (or another color) around its handle to indicate when it is at its maximum torque.

3) Hydraulic

The hydraulic torque wrench is a newer type of tool that has been gaining in popularity due to its precision and ease of use.

It works by transmitting hydraulic pressure (created by a pump) through a hose to the head of the wrench, which then applies this force to the fastener being tightened.

This type of torque wrench can be set from 0-500 ft-lbs or even more in some cases.

This wrench doesn’t require any physical effort on your part, making it ideal for those with joint problems or other health issues; you just need to turn the handle attached to the nut or bolt until you reach your target level of torque.

The downside is that they are usually more expensive than other types of wrenches.

4) Micrometer

The micrometer torque wrench is the most precise type of torque wrench on the market, and it’s also the most expensive.

It works by using a spring-loaded spindle that measures how much force is being applied as you turn a nut or bolt with an attached handle.

This tool can be set from 0-250 in-lbs or more in some cases.

This wrench usually has two scales: one for inch-pounds (in-lbs) and one for Newton-meters (Nm). It also has a ratchet head that allows you to measure torque in both clockwise and counterclockwise directions, which makes it very versatile.


Because this wrench is so precise, it can be used for applications like tightening bolts without damaging them (if used correctly).

The downside is that they’re expensive and require regular calibration.

5) Dial

The dial-indicator torque wrench is a less common type of wrench that uses a spring-loaded plunger and gauge to measure the amount of force being applied as you turn a nut or bolt.

It can be set from 0-300 ft-lbs or more in some cases.

This wrench is ideal for those who want something with more precision than the click-type wrenches, but don’t want to spend the extra money on a micrometer torque wrench.

It has two scales: one for ft-lbs and one for Newton-meters (Nm).

The downside is that it’s not as versatile as other types of wrenches since it can only be used in clockwise directions.

6) Electric

The electric torque wrench is the most popular type of torque wrench on the market, and it’s also the most expensive.

It works by using a battery or AC adapter to create an electrical current that is sent through a wire to the head of the wrench. This current then creates a magnetic field that applies force to the nut or bolt being tightened.

This type of torque wrench can be set from 0-1500 ft-lbs or more in some cases.

This wrench doesn’t require any physical effort on your part, making it ideal for those with joint problems or other health issues – you just need to turn the handle attached to the nut or bolt until you reach your target level of torque.

The downside is that they’re expensive and require regular calibration.

To conclude, there are many different types of torque wrenches available on the market today with varying levels of precision and versatility. It’s important to choose one that is right for you based on your needs as well as what it costs since these tools aren’t cheap!

How to Set a Torque Wrench?

Changing the tool’s setting may allow it to generate more or less torque. Turn the handle clockwise for higher torque and counter-clockwise for lesser torque to change this [4].

To set the torque wrench, loosen the locknut and adjust the desired torque by turning the head. Tighten the locknut to secure the adjustment.

How to Set a Torque Wrench?

The most important part of using a torque wrench is to use it correctly. For example, if you are tightening a lug nut on a car wheel, make sure that you are holding the wrench perpendicular to the bolt being tightened. If you aren’t sure how to properly use your torque wrench, consult your instruction manual or ask an expert.

How to Use Torque Wrenches:

1) A torque wrench is a tightening tool

It uses torque, or rotational force, to apply pressure. The most common use for a torque wrench is to tighten bolts and nuts to a specific tightness, or torque, specification.

This helps ensure that the bolt or nut is properly secured without over-tightening it and damaging the component [5].

Torque wrenches come in different sizes and styles, but all work on the same basic principle: they use a calibrated spring to measure the amount of torque applied to a fastener. When tightened correctly, a torque wrench will stay within its preset range and not vary from its calibrated setting.

Most torque wrenches have an adjustable range of about 15% – 30%. This means that you can set the tool to apply between 15% and 30% more torque than the specified amount.

For example, if you want to tighten a bolt to 40 foot-pounds of torque, you could adjust the wrench so that it will apply between 46-60 foot-pounds of force.

When using your torque wrench for the first time, it’s important that you read the instructions carefully and become familiar with how it works.

2) Handle your torque wrench as carefully as you can

A torque wrench is a delicate tool and can be easily damaged if not handled properly.

The most common mistake people make when using a torque wrench is to use too much force. Applying too much force can damage the calibration of the wrench, rendering it inaccurate.

It’s also important to keep your torque wrench clean and free from dirt and grease. This will ensure that the tool operates correctly and doesn’t get stuck on the bolt or nut you’re trying to tighten.

When not in use, always store your torque wrench in its case or pouch to protect it from damage.

3) A torque wrench should be reset to the lowest value after each use

After using a torque wrench, it’s important to reset the tool to its lowest value. This will ensure that the next time you use it, the torque wrench is still calibrated correctly.

Many torque wrenches have a small locknut located on the end of the handle. Loosen this nut and turn the head of the wrench until it reaches its lowest setting. Tighten the locknut to secure the adjustment

If your torque wrench doesn’t have a locknut, refer to your instruction manual for instructions on how to reset the tool.

4) Only use one hand with a fluent and continuous move

Some wrenches have a ratcheting head, which means that you can use the tool with one hand instead of two. This makes it easier to control and apply more consistent pressure while tightening bolts or nuts.

A ratcheting torque wrench will automatically tighten to the specified amount once you set the desired level.

It’s important not to exceed this setting by applying too much force. Make sure your grip is firm but not tight as this could lead to an over-tightened bolt or nut. If necessary, wear gloves when using a torque wrench so as not to injure your hands from prolonged use in cold weather conditions.

5) Do not use an extension on the handle

A torque wrench is calibrated to apply a certain amount of force. Using an extension will change the way the tool works, which can result in over-tightening or under-tightening bolts and nuts.

If you need more leverage when using your torque wrench, try using two hands instead of one hand with an extension on top of that.

If necessary, you may use a breaker bar with your torque wrench to provide additional leverage without changing how the tool works.

Do not use an extension on the handle

6) Do not overtighten!

When using a torque wrench, it’s important not to apply too much force. Overtightening can easily strip threads from bolts or nuts and damage the tool itself. If anything feels loose after tightening with your torque wrench, stop immediately and do not continue applying more pressure until you have determined what went wrong.

The best way to avoid overtightening is by setting your torque wrench to just below the recommended level for that particular bolt/nut size. This will ensure consistent performance without risking damaging either part of the tool or the fastener being tightened up. You should always err on the side of caution when working with tools like this one!

It may take some practice before getting used to using a torque wrench, but with a little bit of patience, you’ll be tightening bolts and nuts like a pro in no time!

7) Tool maintenance is important

Torque wrenches are precision-engineered tools that require careful handling and maintenance to ensure they work correctly. If your tool has a ratcheting head, make sure it’s locked in place before storing or using.

This will prevent the wrench from loosening during use when tightening bolts or nuts down tight – which could potentially cause damage if left unchecked for too long!

Before applying any torque setting on the wrench itself (for example, turning clockwise), always verify that no other settings have been previously selected so as not to accidentally over-tighten something like a bolt/nut with an overly high amount of pressure applied by mistake!


1. How does a torque wrench click?

A click torque wrench makes a distinct ringing sound when the correct torque has been reached. The handle is twisted to the right to adjust a spring-loaded lever. When the required torque has been reached, the lever breaks, generating a clicking sound [6].

2. What is inside a torque wrench?

The most basic type of torque wrench has two beams. The first is a lever that applies torque to the fastener being tightened and also functions as the tool’s handle. The second beam, which is only connected at one end to the wrench head, serves as an indication beam [7].

3. Why is my torque wrench not clicking?

If your torque wrench is not clicking, there could be a problem with the spring inside of it. It’s likely that the spring has broken or worn out over time and needs to be replaced before using again.

If this isn’t possible right away due to lack of funds, then at least make sure everything else on your tool works properly (i.e., the head rotation should still function correctly even if nothing happens when twisting the handle). So as not to prevent any further damage from occurring while awaiting repairs – which may take up some time depending on how busy they are!

You can also try manually checking whether or not this happens by tightening down one side first (assuming standard/common size nuts used here) without applying pressure yet –  if nothing occurs then try twisting the handle clockwise until reaching its maximum setting before tightening down completely again. This should do it!

Should you double click a torque wrench?

To double-click a torque wrench, you must first set the desired torque on its head by rotating it until reaching that number. Then tighten up one side of your fastener without applying any pressure yet – if nothing happens when twisting clockwise at this point then try again from scratch with another nut/bolt pair (assuming standard sizes are being used).

If no response still occurs after repeating these steps multiple times consecutively, there may be some sort of defect preventing proper operation in which case you should contact customer service immediately so they can help resolve this issue as soon as possible!

Can you break a bolt with a torque wrench?

It is possible to break a bolt with a torque wrench if you are not careful. This can happen if the wrench is set to too high of a torque value or if it’s used incorrectly.

Be sure to always use caution when using this tool and double-check your settings before tightening any bolts down!

How accurate is a torque wrench?

Most torque wrenches are accurate within +/- four percent of the desired torque setting.

This means that if you set your wrench to apply 30 ft-lbs of pressure, it will actually only apply between 28 and 32 ft-lbs [8].

This level of accuracy is important for ensuring that bolts and other fasteners are tightened down to the correct specifications – otherwise, damage (or worse) could occur!

Does a spark plug need a torque wrench?

A spark plug does not need a torque wrench, but it may be beneficial to have one handy. Spark plugs can be tightened by hand or with an adjustable wrench/ratchet as long as they are not overtightened.

Useful Video: How Do Torque Wrenches Work?


  1. https://uk.rs-online.com/web/generalDisplay.html?id=ideas-and-advice/torque-wrenches-guide
  2. https://en.wikipedia.org/wiki/Torque
  3. https://www.rodcraft.com/gb/news/how-to-use-a-torque-wrench.html
  4. https://uk.rs-online.com/web/generalDisplay.html?id=ideas-and-advice/torque-wrenches-guide
  5. https://www.cp.com/en/tools/expert-corner/blog/7-things-you-should-know-about-torque-wrenches
  6. https://home.howstuffworks.com/torque-wrench-stop-when-reaches-torque.htm
  7. https://en.wikipedia.org/wiki/Torque_wrench
  8. https://grassrootsmotorsports.com/articles/are-more-expensive-torque-wrenches-more-accurate