Guidelines for choosing an Impact Wrench

If you’ve ever experienced trying to loosen a large, fretted or corroded fixing, then you’ll appreciate what I’m about to say. Often working in tight spaces or at awkward angles, nuts and bolts can be extremely difficult and time consuming to fit or remove. People all over the globe face numerous problems when working with nut and bolt fixings, including jobs taking too long, broken tools and injuries to the hands. Despite having access to special tools and equipment and a wealth of experience, even fitters and mechanics frequently struggle with nut and bolts.

How can this problem be solved? The tightening or loosening of a fixing is directly related to how much torque you can apply. Correctly tightening or releasing the fixing can't be achieved without the right input torque. Furthermore, it is very important for busy mechanics, and even people at home, to be able to undo fixings in difficult locations, quickly. Similarly, the time taken up by repetitive jobs, like removing and refitting vehicle wheels, can really add up over the course of a day and eat into your profit margin or your family’s patience.

These problems can be eased with the use of an impact wrench. It is capable of delivering a much larger force than you can apply by hand, without additional leverage, and it greatly speeds up the tightening and loosening of fixings, especially those that are hard to reach. I'm sure many of you will understand what I'm saying and you'll definitely want to read on.

What is an impact wrench and how does it work?

An impact wrench is a power tool which is used by people to assist the removal and refitting of nuts and bolts, as it reduces the time taken and the effort needed to tighten or loosen them. There are a variety of different types on the market but they all work in fundamentally the same way. A short burst, or impact, is applied to the fixing in a radial direction, causing a torque spike. There are 3 different types, which are powered by mains electric, air or battery (cordless).

The user can apply a much greater force to the nut or bolt than if they were using a hand tool, as the torque is applied in short impacts. This greatly reduces the effort required by the user, which results in less fatigue and fewer injuries or strains. Especially in the case of a professional user, the time to complete a job can be reduced greatly, meaning more work can be done in the same time making the business more profitable.

But which type is best for my needs?

The 3 types of impact wrench, battery, electric and air, all have their own advantages compared with the others. Garage and race mechanics have long used air impact wrenches to remove and fit lug nuts or wheel nuts, until recent years when many have changed to cordless. Depending on the model, air tools are powerful, fast and robust making them ideal for use in a professional environment. However, they do require a large volume, high pressure air supply to operate and regular maintenance, which means they aren’t really suitable for infrequent or home use. It can also be difficult to move an air wrench around the workshop because it must be attached to the compressor with an airline at all times.

Although less durable than similar air impact wrenches, electric impact wrenches are also fast and can deliver very high torques. Of course, they cannot operate without a mains electricity supply and so have the same problem as air tools when it comes to moving around your garage. However, they can be less expensive than air or cordless impact wrenches, making them an attractive choice for home use. Cordless, or battery, impact wrenches have recently become much more popular with mechanics and home users alike. The more expensive, higher voltage units deliver performance approaching that of an equivalent air tool but without the additional infrastructure. They are also completely portable and the absence of a cord means they can be moved easily around a workspace and used in hard to access areas. However, one point to consider is the weight of the battery packs, especially with less expensive units, as it can lead to operator fatigue.

At present, air impact wrenches remain the most popular with professional mechanics but, as technology continues to improve, the cordless impact wrench will become increasingly popular, less expensive, and ultimately dominate the market.

Ok, but how do I choose a particular model?

To find the tool that's right for you, browse through our impact wrench reviews and look for the one that has everything you need. Only the best selling units are reviewed to save you having to trawl through hundreds of reviews, which usually leaves people more confused than when they started. To describe the size of nuts and bolts that an impact wrench can be used with, we use terms such as 'large' or 'medium' throughout our reviews. When in doubt, always choose the larger capacity impact wrench but you can use these terms as a rough guide. It’s very difficult to specify the exact size of fitting because it is a function of the torque rather than the size and is greatly affected by the condition of the fixing. For example, a rusted fixing would need much more torque to release it than a new one. Another tip for selecting the right size of impact wrench is to consider what size of sockets you would normally use with a 3/8” or 1/2" drive. Other considerations such as design, comfort and socket retention system are self-explanatory and should become clear from reading the reviews.

An impact wrench is a great investment; it takes the strain out of removing stubborn fixings, eliminates skinned knuckles, can help you earn more money AND have more time to spend with your family and friends. Having read this article, you're in the perfect position to read our impact wrench reviews and find the tool that meets your exact requirements.