Impact Wrenches

Pneumatic wrenches, along with hydraulic and electric impact wrenches are one of the most used tools in a workshop, by both amateurs and professionals alike. They are used to tighten bolts to the correct torque, and loosen them, and are one of the biggest labour savers in the workshop. All styles work in the same way, by spinning a mass to a high speed and then engaging a clutch to deliver the torque in a quick burst. Of the different types, air impact wrenches are the most popular.

Many professional (and amateur) workshops use air powered tools, and of them the air impact wrench tends to get the most use. If you do any reasonable amount of work on cars, trailers, boats and the like, you'll probably benefit greatly by adding one to your own workshop. There are several choices you need to make before buying one though - specifically power source, drive size, and case/style. Let's take a look at power source first.

While air powered wrenches are the most popular, they might not be the best choice for the small home workshop. Since they use compressed air as their power source, you'll need a high power compressor to run one, which can be a considerable extra expense if you don't already have one. For a home workshop, where an impact wrench will only be used on occasion, a mains powered or cordless wrench is probably more suitable. With modern batteries, a cordless wrench is quite powerful enough for most work and they are quite reasonably priced, especially when you consider that you don't also need to purchase a compressor.

The next consideration is what size of drive and sockets you'll be needing. This will be influenced by what you'll be using the wrench for, and whether you already have some sockets. In general, the heavier the work is the larger drive you'll need. 1/2" sockets are quite suitable for working on most cards, with 1" or even 2" being needed if you'll be working on commercial or plant vehicles. Drive sizes over 2" are normally only used in heavy industrial workshops.

Finally you'll need to decide on a style of unit. For the home workshop a pistol grip is quite common. Shaped like a hand drill, they offer a reasonable grip to enable medium torque levels while being quite easy to manoeuvre into tight spots. If you need something heavier then a D or T grip will be needed, while the smallest drive sizes can be used on small tools shaped like electric screwdrivers, but they are only useful for very light work.

After making your decisions for style, drive and power source you can search for a suitable model. Most of the big name brands offer a wide range of models to suit every budget, but don't ignore the budget brands. Even some of the cheaper models are quite capable, and real bargains can be had, especially if you look for discounts through online stores.