How Does A Torque Wrench Work? Basic Principles You Need To Know

Today, it is important to have a fully equipped and functional tool kit in your home. And a torque wrench is an important part of your toolkit. But before you can own and work with a torque wrench, it is essential to know: how does a torque wrench work? How and when to use the torque wrench?


There are various applications of a torque wrench in our day to day life. It can be used for a large number of household repairs and maintenance and other production.

What is a torque wrench? A torque wrench is a device used to apply a specific amount of torque. It most commonly takes the form of a socket wrench with a special internal mechanism. If you are an active worker and require a tool that can allow you to apply a specific amount of torque, then all you need is a torque wrench.

Types Of Torque Wrench

A torque wrench works on the basis of the four mechanisms given below, depending on its type:

Beam Type Torque Wrench

In a beam type torque wrench, the pointer beam is attached to the wrench’s head. When the wrench is used to apply torque, the beam stays in the place and the scale beneath the pointer indicates the amount of torque being applied.

Dial Indicator

A dial indicator torque is a simplified beam type torque wrench and has a dial attached with the torque. This dial indicates the amount of torque being applied to the nut or bolt.

Clicker Type

A clicker type torque wrench has a spring loaded lever, which is adjusted by twisting the handle to attain the required torque. When the required torque is achieved, the spring loaded level breaks to create a clicking noise.

Digital Electronic Torque Wrench

These are the most expensive of all the four types and come with a digital dial that displays the torque being applied.

How Does A Torque Wrench Work?

A torque wrench, as the name indicates, works on the basis of torque. The amount of torque that is applied is dependent on the length of the wrench and the force being applied to the tool handle. The torque applied is proportional to the length of the wrench.

A torque wrench uses a deflection beam or a calibrated spring system to find the amount of torque being applied to a nut or a bolt. This value of torque is displayed on the associated meter or dial.

The torque wrench may display the torque being applied in foot-pounds (ft. lbs.), inch-pounds (in. lbs.) or Newton-meters (Nm). Typically, a torque wrench can be used to generate torque up to about 200 to 250 ft. lbs.

Torque wrench with handles can be used to set the required torque. When the required torque is achieved, the wrench produces a click. The mechanism of such kinds of torque wrench is found compactly stored in their handles.

Torque wrenches with external rod above the wrench shaft are also available. The rod points towards a semi-circular gauge at the handle. The gauge has a piece of steel at the center that can be set to the left or to the right.

When the torque is applied, the rod pointing at the gauge stays straight and eventually contracts when the desired amount of torque is achieved. When the desired torque is achieved, there is an audible click to inform.

How To Use A Torque Wrench?

Now that we have learned how does a torque wrench work, it is time to learn about how to use it.

  • When using a torque wrench, it is important to know the torque required for the fasteners. If you do not know the torque required, don’t guess it. Try to find out from other sources.
  • To tighten a fastener, first, fix the nut or the bolt with an ordinary wrench or socket till it is a snug fit.
  • Use the torque wrench to tighten the fastener according to the specification.

You can easily learn how to use a torque wrench follow this video:

Wrapping Up

Torque wrenches are an extremely important tool in the modern times. It allows you to tighten a nut or a bolt with a specific amount of torque. This is essential in situations where the bolt or nut should be tightened to an exact amount and can cause problems and damage in the future if they are not secured perfectly.

A torque wrench is a must have tool when it comes to repairing your automobile yourself and is essential to tighten cylinder head bolts, connecting rod bolts, main bearing cap bolts, crankshaft pulley bolt among many others.

To use a tool to its potential, it is important to know about the tool and how it works. I hope that with this article, you must have understood the basics and working of a torque wrench.

What are your views on this? Do let me know in the comments.

Abigail Jones

Hi, I'm Abigail. I like spending time tearing my house apart and putting it together back again. Join me on home improvement tutorials, tips on my blog.

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