Impact Driver vs. Impact Wrench - How to Get the Right Tool

Last update February 15, 2019
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Tools with the word “Impact” in the name must be powerful, but what are they used for? If you are debating between getting an impact driver or an impact wrench, read on to find out more about them.

Impact Driver

Impact Driver

As the name implies, an impact driver is a tool used for providing a sudden rotating downward force in relation to screws or bolts that require a high torque in order to loosen properly. They are often also fitted with a reverse mechanism that allows them to tighten bolts or screws in the same manner. These are a bit different than many tools that are labeled as “power drivers”, as an impact driver provides a sudden force whereas many other power drivers apply force in a more gradual manner. Impact drivers also tend to be extremely powerful, much more so than a power driver.

Impact drivers can come in several varieties, both powered and unpowered, and are very commonly used in professional services such as auto repair, where it is often necessary for screws and bolts to be fastened and unfastened using a very high torque. In such cases, a screw or bolt that is not fastened tight enough can become a huge problem, and one that has been over-torqued can make the ability to remove it extremely difficult. However, there is a bit more to an impact driver than just it’s ability to tighten or remove bolts and screws. Many recent powered impact drivers come with a battery built in, to allow for uncorded use.

Many popular power tool manufacturers make different impact driver models, including Black & Decker, Dewalt, Makita, and many others. Take a look at this impact drivers review in order to find the right one for your needs.

How to Use an Impact Driver

How to Use an Impact Driver

Impact drivers are high powered tools, and as such, it is extremely important to use them in a correct and safe manner. Improper use of an impact driver can cause severe damage to whatever you are working on, or worse, bodily injury if the proper care isn’t taken. This applies equally to both the powered and unpowered varieties, as both kinds deal with a high degree of force.

Impact drivers typically use ¼ inch hex bits, which can often be included with the impact driver, or purchased separately from any hardware store. Having a proper set of them will ensure that you have the right hex bits for whichever screws or bolts that you will be working on. The head of the hex bit should fit snugly on the head of the screw or bolt, in order to prevent cam out. Many impact drivers may include a metal sleeve that fits over the hex and screw head to assist with cam out prevention.

How to Use an Impact Driver

A powered impact driver works in a very similar manner to a power driver, and often can even be used in place of one for ordinary driver tasks. The important thing to remember when using it, though, is that the force that is delivered is immediate, so keeping the hex bit steady and centered before operation of the tool is of the utmost importance. The powered impact driver will often use a trigger like a power driver to start the operation, and it should just need a quick trigger pull and release to operate. Holding the trigger too long may cause damage when tightening a screw, or cause the screw to fly out when loosening. The key is to make sure it is operating in only short burst.

An unpowered impact driver works a little differently, although the principle in its use is the same. Instead of using a powered rotation, the rotation of the hex bit is created when the outer sleeve of the tool is struck with a hammer, which also forces the impact driver down in order to prevent cam out. This provides a sudden burst of force which is enough to loosen the screw, which can then be unscrewed manually. When tightening a screw, it is best to screw it in all the way manually first, and then use the impact driver in the same way to ensure it is at maximum tightness.

What Is an Impact Driver Used For?

Impact Driver in Use

As stated before, an impact driver is good for loosening or tightening screws or bolts that require a high amount of torque, or which are stuck in place due to effects of corrosion. They are best used with ones that fasten into heavy types of metal or iron, require high torque, and must be fastened tighter than what a normal screwdriver can accomplish. Using an impact driver on weaker types of material or with very light screws is not recommended, as they can run a high risk of causing damage.

It is also important to note that they are best used with Philips head screws and square socket head screws. Slot head screws are usually not best used with an impact driver, as they run a higher risk of cam out. Impact drivers may not be useful for other types of screws.

Impact Wrench

Impact Wrench

Just as impact drivers are used for screws, an impact wrench is used in a way that the word “wrench” implies. An impact wrench is a powered tool used in the same way as a socket wrench. Their primary purpose is to loosen or tighten a lug nut in a manner or for instances where a high degree of torque is necessary. Unlike an impact driver, an impact wrench is strictly a powered tool that uses a source of power such as compressed air or electricity to generate a sudden force. Although the compressed air wrench has traditionally been used in professional settings such as auto repair shops, the electrical impact wrench is more popular now for both home and professional use. Many recent impact wrench models use an internal battery, making them quite easy to handle and use even in smaller spaces.

Finding a good quality impact wrench is similar to finding any good quality power tool. Some of the best impact wrench models are made by Dewalt, Porter-Cable, Milwaukee, Aircat, and others. Take a look at some of the best impact wrenches to see which models will be most suitable for you.

How to Use an Impact Wrench

Impact Wrench Application

An impact wrench is generally an easy tool to use, and as it often does not deal with sharp or pointed objects, can be safer than an impact drive. However, as they do generate a sudden burst of power, it is always best to maintain proper safety precautions, such as using eye protection and keeping your hands away from the moving parts.

An impact wrench has a socket mounted at the end of an output shaft, which in turn connects to the motor. When operated, the motor is powered by its power source, turning the shaft at a high speed and thus delivering high torque to the lug nut through the socket head. The basic usability is very similar to that of an impact driver, in that a sudden short burst of power is used to loosen or tighten the lug nut. This makes it much easier to use for high torque lug nuts than a traditional socket wrench. However, it is often best to use only when a regular socket wrench won’t meet the need for high torque.

What Is an Impact Wrench Used For?

Impact Wrench in Use

Just like with impact drivers, an impact wrench is very commonly used in the automotive industry, particularly in auto repair shops, where lug nuts are commonly used for holding a car wheel to the axel. Likewise, they are used in other industries involving both the manufacturing and maintenance of other vehicles, such as airplanes, boats, and many types of heavy machinery.

The main use of an impact wrench in these cases is to loosen lug nuts that have been previously applied with a high degree of torque, or are otherwise frozen or stuck in place due to corrosive effects. They are also often used in reverse for applying lug nuts when high torque is required.

Bottom Line: Differences Between an Impact Driver and an Impact Wrench

Differences Between an Impact Driver and Impact Wrench

Many of the differences have already been stated before, but it is best to repeat them in order to ensure that any confusion about it has been eradicated. Here are the highlights of the main differences between an impact driver and an impact wrench.

Impact Driver

  • Used for tightening or loosening screws and bolts
  • Both powered and manual models
  • Work best with Philips head or square socket head screws

Impact Wrench

  • Used for tightening or loosening lug nuts
  • All models are powered, either by using compressed air or electricity
  • Work best with strong lug nuts that require a high degree of torque

Armed with this knowledge, you should know everything you need to know about both the impact wrench and impact driver, what they are used for, and the differences between them.