Cordless impact wrench purchasing advice: how to choose the right product

  • The most important in a nutshell
  • With an impact wrench, you can tighten and loosen nuts as well as unscrew deep-lying screws.
  • Different attachments for the rotary head allow to perform numerous operations and process different materials.
  • Additional features such as an LED light, gradual speed adjustment and left-right rotation make your work easier.
  • Speed and torque are important features to keep in mind when making a purchase.

What is a cordless impact wrench?

An impact wrench is a handy, mechanical tool with which you can quickly screw in and remove large screws or loosen and tighten nuts. Visually, the device resembles a small drill or a cordless screwdriver. You can attach sockets and interchangeable screw heads, the bits, which differ in shape and size, to the attachment located at the front. This equips you for a variety of work areas – from assembling furniture, doors or kitchens, to screwing work in wood, metal and plastic, to erecting fences or wooden structures.

The pulsating rotary movements generate more force than with a cordless screwdriver. This means that screws can be quickly and reliably tightened or loosened. In the household, the device performs well in the workshop as well as when assembling furniture. It can also be used to loosen wheel nuts on cars.

Car mechanic with impact wrench
There are many possible applications for cordless impact wrenches, especially on cars.

Advantages and disadvantages

The advantage of battery-powered impact wrenches is that you can work without being dependent on a power connection or the length of a cable. This gives you maximum flexibility when working. Even more, the power consumption during battery charging is lower than when operating with a corded cordless screwdriver. However, keep in mind that your working time depends on the capacity and charge of the battery.

The disadvantage is that cordless impact wrenches are less powerful than models that are powered by electricity or compressed air. Accordingly, while not suitable for all tasks, they are always a good choice for everyday work. However, if you own an auto repair shop, for example, and need to unscrew wheels more often, a more powerful impact wrench is a wiser purchase.

Attention: Danger of confusion

A cordless impact wrench should not be confused with a cordless impact drill. The latter actively drills into the depth. It is used to create holes and remove material. For a better distinction, cordless impact wrenches are also called cordless rotary impact wrenches, since the impact pulse moves in the direction of rotation and not in the depth. An ordinary cordless screwdriver, on the other hand, is in a sense an electric screwdriver for which you have to use less manual force.

The most important properties

Depending on the application, you should pay more or less attention to the performance data of the cordless impact wrenches. Externally, the models usually hardly differ, at most in color and marginally in their dimensions. However, a look at the inner workings reveals that some are capable of significantly more than others. Professional devices are also characterized by a longer battery life; check in advance how long a battery charge is capable of lasting so that you can be sure that this is sufficient for your work plans. The price range of various cordless impact wrenches ranges from around 100 euros for smaller devices to 400 or 500 euros for professional devices.


The weight of the tool is usually specified by the manufacturer without the battery. So, as a precaution, add a few hundred grams for the actual weight. Since you usually use the cordless impact wrench with one hand, the total weight is an important factor when working. Especially when working for longer periods of time, it makes a difference whether the device weighs only 1.8 or over 3.0 kilograms.


The rotational speed is not to be confused with the torque. The speed is specified in revolutions per minute (rpm) and describes how fast the screw head rotates when idle. A value of around 2,000 revolutions per minute is sufficient for working with most materials; however, many cordless impact screwdrivers achieve a higher speed. The power can often be set or regulated in several stages.


The torque is the decisive value that provides information about the performance of the tool. It is specified in Newton meters (nM) and indicates the strength with which the tool can loosen a nut or screw in a bolt. Therefore, make the purchase of a cordless impact wrench dependent on the work you want to do. For a tire change, for example, you need a tool that has a power of at least 350 to 400 Newton meters. Particularly powerful devices reach a value of over 650 Newton meters, but there are also significantly weaker ones that are sufficient for furniture work, for example. Weaker, lighter models are often described as DIY cordless screwdrivers.

Impact wrench changing a tire
For changing tires, the cordless impact wrench must have a certain power.


When working with a cordless impact wrench, a volume in the range of 100 to 110 decibels is often reached. This is about as loud as a circular saw or a rock concert and can be not only stressful but also damaging in the long run. You should therefore consider hearing protection, especially if you use the device for a longer period of time. However, there are exceptions: Some devices only reach a volume of 80 decibels, which is noticeably quieter.


The handle is usually equipped with soft material, so you always have a comfortable grip. In addition, it is ergonomically adapted to your hands so that you can work comfortably even over longer periods of time. Thanks to an anti-slip coating or nubbed surface, you have a firm grip on everything, even with sweaty hands.


Most cordless impact wrenches are driven by a brushless motor. One advantage of this design over a conventional carbon brush motor is the significantly longer runtime. They can also achieve a stronger performance with it. Carbon brushes are also wear parts that need to be replaced after a certain amount of time. This is not necessary with a brushless motor.

Battery included?

Keep in mind that especially large manufacturers of electronic tools often deliver their devices without a charger or even without a battery, which is why you may have to order these parts additionally. The idea behind this is that the same battery can and should be used for different devices from the same manufacturer. Keep in mind that it can be handy to always have a charged spare battery on hand so you don’t have to interrupt your work.

Optional functions

Not all cordless impact wrenches have the same setting options. Optional functions that many devices offer are helpful in numerous everyday situations. However, you must ultimately decide for yourself for which work you need these options.

LED lighting

For work in dimly lit rooms or, for example, when the place where a screw has to be pulled out of a wall is at a dark angle, a small illumination is useful. LEDs around the socket of the screwdriver provide small-area light and always point to where the tool is working.

Left-right rotation

You can change the rotation of the screwdriver head via a switch. To tighten screws and loosen nuts, the screwdriver must move clockwise. If, on the other hand, you want to loosen screws or tighten nuts, the screwdriver must turn counterclockwise. Even if the screw gets jammed, it can help to briefly change the direction of rotation.

Power levels

You can often adjust the power or speed of the screwdriver via a regulator, for example in three stages, like a gearshift. This limits the maximum speed to a certain value, which in turn saves some of the battery energy. In other words, you specifically use a lower speed than the maximum possible. For example, a screwdriver does not have to rotate at 2,800 rpm if you only want to pull a screw out of a wooden wall.

Various essays

Various sockets are available for a cordless impact wrench, which you insert into the head of the screwdriver. For example, there are different diameters for nuts: smaller ones for assembling furniture or other household tasks, and larger ones for tightening wheel nuts. Phillips and slotted screws in various sizes can be tightened with the right attachment. Special versions, for example for Torx or Allen screws, are usually not included in a conventional set, but can be purchased separately.

Battery impact wrench
A cordless impact wrench is useful in many situations.

Sockets and nuts – as the attachments for nuts are called – that you already have for a manual ratchet can also be used for less powerful cordless impact wrenches. Only at a torque of 300 Newton meters or more do you need special resistant nuts. These are called power sockets and are specially designed to withstand higher loads. They are standardized and colored black so that they can be distinguished from ordinary sockets.