What is an Impact Wrench? Better Solution for Impact Driver

When you need to lose a nut of your vehicle easily, you can use an impact wrench. An impact wrench is a driver that can tighten or lose the lug nuts. Mechanism, usage, price, power, speed, and many more are different when considering the impact drivers. So let’s see what an impact wrench is?

An impact wrench is a high torque driver that can use to tighten or loose the lug nuts. Impact wrenches are with more torque than impact drivers. The torque is produced by torque multiplier using an epicyclic gearing mechanism. A friction ring and detent pin are used to mount the socket to the impact wrench.

When considering the impact wrench and impact driver, both are with the same mechanism. But there are small differences. These small differences are lead to handle more torque. So keep reading on everything you should know about impact wrenches.

How Does an Impact Wrench Work?

An impact wrench is used to lose or tight the lug nuts, which requires more torque tasks. Therefore impact wrenches need more torque for the tasks. When considering the impact driver, there is a rotational hammering mechanism that helps to produce the torque for the driving process. That much torque is enough for driving screws inside the wood.

But when we consider the impact wrench, we need more torque.

How does it produce that torque by using the same tool? There is an amazing engineering solution called torque multiplier. The torque multiplier is the main mechanism that is added to the impact driver mechanism.

Torque Multiplier

Torque multiplier is a combination of a gear system. It is named planetary gears. Epicyclic gearing mechanism can control the gear ratios and then change the torque. According to the rotational speed, torque can be controlled. That is more than the impact driver. There is no such mechanism in the impact driver.

The number of impacts is measured as impact per minute (IPM)

Epicyclic gear system Source

Finally, the impact driver produces more torque using the epicyclic gear system.

Read More About –Impact Driver Vs. Impact Wrench – What You Should Buy?

Impact Wrench Chuck and Collet

An impact wrench is used for high torque tasks. The produced torque is transfer to the lug nut using the chuck. We call this is the collet. Normally impact drivers have hex shank chuck. But impact wrenches have two main types of collets.

Most impact wrenches are with 1/4″, 3/8″, 1/2″, and 1″. 1/2 and 1″ are used for extremely heavy-duty works in industrial level usage.

Friction Ring
The friction ring can directly mount to the socket. That is not much safe. The friction ring is easy to use with quick changing the sockets. But Pin detent will take more than that.

Pin Detent
Pin detent is a safe way to mount the socket in a secure way.


When we consider the collets, we must pay attention to the adaptors. You may think to use the impact wrench as an impact driver or drill. Of course, you can. You will need an adaptor for use as an impact driver or drill.

When you use adaptors, make sure that they are with enough strength. An impact wrench is with high torque. Due to torsion, the adaptor can be damaged easily. Use enough strength adaptor for impact wrench.

Torque and Speed of Impact Wrench


When we consider the speed of the impact wrench, it is less than the impact driver. Using an epicyclic gearing mechanism, its speed is reduced, and torque has increased.


The most important factors of the power tools are speed, torque, and power. Let’s see how these are affected.

Torque is essential for losing or tight the lug nuts. Lug nuts should be tight with using high torque. Impact wrenches produce more torque for this. Normally we measure torque as below.

Impact driver – in-lb
Impact wrench – ft-lb

You can convert each other using this.

  • 1 ft-lb = 1.3558 Nm
  • 1 ft-lb = 12 in-lb
  • 1 in-lb = 0.112 Nm

Impact wrenches always with high torque with considering the impact drivers.

Tighten torque (forward torque)
Tighten torque is the torque for tight the lug nut.

Breakaway Torque (reverse torque)
When you need to lose the nut, you will need more torque than high torque. This is breakaway torque. That is always less than the tightening torque. Breakaway torque is the maximum torque that a tool can produce.

You can see some tested dates for Milwaukee, Rigid, Dewalt, Ingersol rand, and AC Delco as below.

Tool with PriceForward Torque (psi)Backword Torque (psi)
Milwaukee (156$)17502000
Rigid (168$)15001725
Dewalt (143$)9001000
Ingersol Rand (190$)675650
Delco (96$)450275
Source: Project Farm
Impact Wrench Comparison

Noise of the Impact Wrenches

Impact wrenches are operated with the hammering action. Due to this, there is a noise. Normally impact driver noise is less than the impact wrench noise.

Impact wrench noise is 92-97 dB when the impact mechanism is not activated. When the impact mechanism is activated, it will be 100-105 dB. The suitable noise level is 85dB.

Therefore using an impact wrench is a bit noisy.

Types of Impact Wrenches

There are types of impact wrenches.

  • Pneumatic Impact Wrenches
    For the extremely high torque requirements, those tools are used. Compressed air is used to power up the tool. pneumatic impact wrenches are used in garages, industrial usage etc. Compressed air is supplied using the hose and when it moves through the impact wrench it releases the compresse air power by rotating the tool. Those are with high noisy high power.
  • Cordless Impact Wrenches
    Thses are mostly used for mobile usage and domestic usage. These tools provide less torque. Due to limited power supply. But it is suitable for tight the lug nut of a car. Cordless impact wrenches are easy to use. This is the major factor for using this tool.
  • Hydraulic Impact Wrench
    The power source is hydraulic for the impact wrenches. It is used to achieve proper tightening or loosening of a connection. A hydraulic torque wrench is significantly quieter, lighter weight and more accurate than pneumatic impact wrenches capable of similar torque output.


Impact wrenches are used for lug nuts works. Normally impact wrench is more powerful than an impact driver. Collet, mechanism, sockets are mainly different things when considering the impact driver and impact wrench.

Using an impact wrench is a bit noisy task, but it is more efficient. Using adaptors, you can use the impact wrench as an impact driver as well as drill.

Tom Mackency

Tom Mackency

Hi, I am Tom Mackency. It has been 10 years that I have been working as a professional woodworker since 2013. I am really enjoying my carrier by creating many kinds of projects in my workshop. But mostly I like for home improvement projects. Home improvement and DIY projects are the most interesting things for me. More than that, the coolest things are power tools. Those are very precious and efficient than a decade ago. So I try to introduce so many things about power tools, woodworking, DIY projects, home improvement and many more interesting topics here.