Whether you need to remove a particularly stubborn nut, or drive a screw into an especially hard surface, impact power tools are fantastic at enabling you to handle a wide range of tough tasks with ease.

Modern innovations coupled with intensive R&D on lithium-ion batteries, has seen the market become dominated by impact tools of the cordless variety. Now powerful enough and efficient enough to replace their corded counterparts (and even some tools that are pneumatic), while they are all useful additions to a workshop or toolkit, it’s important to recognise that not all impact tools offer the same advantages.

To help you understand the difference between an impact driver and an impact wrench, and to have a better idea of which one you should buy (unless you choose to buy both, of course), here is a handy comparison guide:

Drive

When you look at both an impact driver and an impact wrench, it’s clear to see that their designs are very similar, until your eye comes to rest on the drive. Sometimes referred to as a chuck or collet, the drive of an impact driver can only accommodate hex bits of a ¼ inch, which is ideal for fastening a variety of screws. On an impact wrench, however, the drive is referred to as a ‘square drive,’ and they are available in three sizes of ¼ inch, 3/8s of an inch, and ½ inch. These drives also come in two different styles, known as friction ring or pin detent. Impact wrenches are operated with sockets, rather than screwdriving bits.

Power

You will also notice another distinct difference between the power and torque of the two impact tools. While both deliver undeniably great power, how that power is applied and used, differs significantly. Let’s look at an example:

Typically used to either drill long screws into different materials, or remove them, an impact driver’s torque is measured in inch-pounds, or in-lb. Impact wrenches on the other hand, are most commonly used to tighten or loosen hex head fasteners, such as bolts and nuts. The force created when used for such tasks is measured in foot-pounds, or ft-lbs, and when the two tools are compared, impact wrenches usually come out on top, with more power and torque available.

To recap

While very similar in the way in which they are designed, the two tools share no other similarities, and are often seen as being trade specific. As such, it really depends on what type of application or task you plan to use the tool to help you with. For example, if you’re undertaking a DIY project at home, or are working on a job site that requires you to drive in a lot of screws, you’ll definitely want to be using an impact driver; its speed and power will help you make short work of the task. However, if you’re working on industrial machinery or automobiles and need to fasten or remove lots of nuts and bolts, an impact wrench should be your tool of choice thanks to the higher torque it offers.