From The Rock

Impact wrenches are powered socket tools, powered by compressed air or electricity, they are one of the most common and useful tools in both the professional, and serious amateur workshop. Impact wrenches work by spinning a “hammer” to a high speed, and then suddenly engaging the socket, to deliver a sudden burst of torque. While electric (both mains and cordless) and hydraulic models are available, it is the air impact wrench which is by far the most popular.

Air impact wrenches are by far the most popular of all air tools, and if you’re doing any serious amount of automotive work you’ll definitely want one. Before you rush out and make a purchase however, there are a couple of considerations – power source, and socket size. Power source will depend on your budget, and what tools you already have. Socket size will depend on the type of work you’re doing.

As already mentioned, air impact wrenches are by far the most popular, but that doesn’t mean they are your only choice. While they are relatively inexpensive, and offer good power, they do need a compressor as a power source. Unless you already have a suitable compressor that will add a considerable amount to the cost of the tool. If you don’t have a suitable compressor, and are doing only occasional or light automotive work (such as in a home workshop) then an electric or cordless wrench is probably a better bet. These days the cordless wrenches are more than capable of light work, and are reasonably priced.

Once you’ve decided on a power source, your next choice is drive size. If you already have a large selection of sockets of a particular size then it makes sense to get a wrench that will allow you to use them, otherwise your choice should be guided by the type of work you’ll be doing most. In general, cars and bikes will require 1/2″ or possibly 1″ sockets. If you’re working on big SUVs or commercial vans and trucks then you might want 2″. Anything larger tends to be used only in industrial plants.

There is one other choice to me made, and that is style. The smallest wrenches are shaped like a screwdriver, but they are only capable of delivering low torque. Most 1/2″ wrenches are of the “pistol grip” variety, shaped like an electric hand drill. As you move up to heavier duty tools you’ll start to come across D and T grips which allow for a much firmer hold, and so much higher torque levels. The correct style for you will depend on the type of work you’ll be doing, so take that into consideration when making a purchase.

So, now you know what sort of wrench you need you can start looking for a suitable model. Many power tool brans such as Sealy, Matika, Draper and SIP offer a wide range of models to suit different budgets. Your best bet is to scour the online stores for a bargain, as you’ll find many models discounted online.

For more information about air impact wrench visit www.airimpactwrench.org