Picture a racing car screeching into the pit stop. Mechanics rush in right away, remove the lug nuts and replace the wheels. The power tools they use are called impact wrenches. They’re found in the tool kits of most mechanics who are worth their salt. But what do you use an impact wrench for?
Is it worth adding yet another tool to your gear? This page will explore the nuts and bolts of impact wrenches. We’ll discuss their uses, their drawbacks and other tools you might like to consider. If you’re thinking of using an impact wrench but aren’t sure where to start, make sure you read on.
One thing to mention before we go any further is that an impact wrench should not be confused with an impact driver; they’re different tools. Check out our Impact Drivers VS Impact Wrenches post to learn the differences in detail.
Impact wrenches are extremely high-torque power tools with orders of magnitude more power, force and grip than a manual wrench tool. An internal hammer mechanism inside the impact wrench allows it to spin at immense speeds. Their primary use is for removing and tightening lug nuts, regular nuts and bolts.
Old-school impact wrenches are pneumatic and most often used by specialists. There are now three common types of tool that make them far more accessible to hobbyists.
Our Favourite Impact Wrench
If you’re in a rush and just want a quick recommendation, this is our favorite all-rounder impact wrench. Milwaukee boasts that this heavy-duty tool delivers 2X the removal speed for bolts than other options. The amount of power here means that even the most stubborn rusted bolts should be no problem.
The 2767-22 comes with 2 battery packs as standard, meaning you can keep working for longer. You’ll be comfortable doing this too thanks to this tool’s rubberized, ergonomic design. The compact build of this impact wrench makes it much easier to squeeze into hard-to-reach places.
- Super comfortable to use
- No need for a pneumatic tool to remove rusted bolts
- Our favorite impact wrench
- It’s a little pricey
Types of Impact Wrenches
There are three main types of impact wrench to choose from. They’re all best suited for different contexts so it’s worth getting to grips with what distinguishes them.
Electric Impact Wrench
An electric impact wrench, as you may have guessed, runs on electricity. This is powered by either a lithium-ion battery or a mains supply. As a general rule, corded options come with a little more oomph thanks to their mains power source. Battery powered options are usually lighter and better for portability.
Air Impact Wrench
Air impact wrenches are the old-school, pneumatic tools we mentioned earlier. These powerful impact wrenches work by using compressed air to drive the hammer mechanism and achieve a high torque . A bulky air compressor is necessary when using one of these impact wrenches.
Despite their size, air impact wrenches are still preferred by many professionals thanks to their powerful design.
Hydraulic Impact Wrench
Hydraulic impact wrenches are commonly used in an industrial manufacturing context. They use hydraulic fluid to power the hammer mechanism and operate at an exceptionally high speed.
Common Impact Wrench Mistakes
There are a few pitfalls that many workers fall into when using impact wrenches. If you’re a newbie, you’re in the right place. Read on to avoid these common mistakes.
Using the Wrong type of Impact Wrench
You don’t need a model that runs on compressed air if you’re only ever performing lightweight tasks. Consider the type of work you need an impact wrench for and use this information to choose the right tool. If you’re working with rusted, stubborn bolts then you’ll want to consider a more powerful compressed air or hydraulic option.
Not Wearing Hearing Protection
The torque on impact wrenches makes a lot of noise. They can damage your hearing very quickly if you don’t use adequate protection. Wear ear defenders for even quick work tasks.
Over Tightening the Nut
This is another impact wrench mistake. It can damage your tool, the nuts and even be dangerous if the nut cracks. Check the recommended torque for any nut you’re working with.
Using the Wrong Size
Impact wrenches are built to accommodate a wide variety of different lug nuts and bolts. Make sure you’re using the right size for the job.
The Main Uses
So what’s the point of these high-torque tools anyway? The guide below outlines the main uses for an impact wrench. We’ll also discuss some common alternatives that some consumers might find more appropriate.
Replacing care tires is probably the number one use for an impact wrench. If you’re a piston-head who’s always tweaking your ride, an air impact wrench could be a great addition to your garage setup. For quick tire changing in times of need, keeping an electric impact wrench in your trunk might get you out of a sticky situation one day.
There are a surprising number of home DIY tasks that are made easier by a good impact wrench. Are you building something with a high bolt count? Maybe you’re fixing a shelf in your garage or attaching a metal play set to the floor of your yard; an impact wrench could make these jobs less time consuming.
It’s probably best to use a less powerful electric impact wrench for home tasks. You don’t want to risk breaking the thing you’re working with! Impact drivers are also a great option for many home tasks like these.
Mechanics at auto-repair shops use an impact wrench practically every day. These are most commonly in the form of an air impact wrench. Mechanics have to quickly remove and replace tires and other components from cars multiple times a day. An impact wrench is what makes this possible.
Construction & Manufacturing
Work environments that involve construction or demolition often call for either an air impact wrench or a hydraulic tool. Professionals rely on these machines to quickly build or tear down key structural elements of buildings. A manual wrench just can’t match the torque of an impact tool.
The power of these wrenches make them an excellent option for specialists and hobbyists with specific demands. For more casual work, however, this power can be a little overwhelming. If you’re not doing the work of a professional, an impact wrench can damage the bolt you’re working on.
The wrong tool for the wrong bolt can waste a lot of time and money for everyone involved. These are very high-vibration tools, so it’s worth considering if an alternative might be better.
An impact driver can fulfil many of the same tasks of their wrench counterparts. The difference is that they generally use a lot less power and are therefore better suited to more lightweight tasks. If you’re not a specialist and need a tool that can help with everyday tasks, you might be better off with an impact driver.
Check out our Impact Drivers VS Impact Wrenches post to learn the differences in detail.
Pulse tools use a hydraulic drive system to achieve a similar torque to an impact driver or wrench. The difference is that they apply power in small increments, reducing the amount of vibration and resulting damage to the nut you’re working on.
These tools are considerably more expensive than an impact driver or wrench, but they can be a great addition to your toolkit in the right context.
The modern electric and hydraulic wrenches have significantly improved the accessibility of these tools. You don’t need to lug a tank of compressed air around for power anymore.
If you’re a mechanic or similar specialist, you probably use of these tools every day. If your requirements are a little more general, and perhaps less heavy duty, it might be worth double-checking if you wouldn’t be better off with an impact driver instead.
An impact driver can fulfil a lot of the same tasks as a wrench without the risk of damaging your work pieces. If you know that you need the power, then go for it. Otherwise, impact drivers might be the way to go.
If you’re still not sure, we’ve got a great guide to impact drivers on this site. If you’re looking for impact drivers that can help you quickly remove and replace lug nuts then it’s worth the read.