Best Air Impact Wrenches

Updated April 2019
Why trust BestReviews?
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.
Bottom Line
Pros
Cons
How we decided

We purchase every product we review with our own funds — we never accept anything from product manufacturers.

14 Models Considered
6 Hours Researched
1 Experts Interviewed
290 Consumers Consulted
Zero products received from manufacturers.

We purchase every product we review with our own funds — we never accept anything from product manufacturers.

Why trust BestReviews?
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.

Shopping guide for best air impact wrenches

Last Updated April 2019

Air impact wrenches have been the professional's tool of choice for everything from changing tires to building ships for over 60 years. These tools are powerful, reliable, durable, and easy to maintain. Many modern air impact wrenches are both more compact and more affordable than the full-on pro models, which makes them a popular choice with home mechanics.

BestReviews has been assessing the capabilities of a wide range of these tools. Our recommendations encompass everything from entry-level air impact wrenches to top-of-the-line models. There's something there for every need and budget. We've also put together the following air impact wrench buying guide, which delves into all the details you need to consider when buying.

Chicago Pneumatic was responsible for introducing both the electric wrench and air impact wrench in 1939. The same company also produced the airbags deployed by the Apollo 11 space capsule when it splashed back down to Earth in 1969.ur test process

Key considerations


How an air impact wrench works

An air impact wrench (also known as an air gun, impact gun, or impactor) has a simple job: to loosen or tighten nuts and bolts. The advantage it has over an ordinary wrench is the amount of torque (twisting force) it applies.

Power is supplied either by an electric motor in the impact wrench or by air from a compressor. Unlike a drill, which delivers constant rotational force, the impact wrench delivers a series of rapid strikes with short pauses – these “impacts” jar a bolt or nut loose. It's a bit like hitting your standard wrench with a hammer but much more effective.


Electric vs. air

Electric: Electric impact wrenches are common among nonprofessional users because all you need is a convenient outlet and away you go. Cordless models are increasingly popular because they can go anywhere, and improvements in battery power mean there's less of a performance disadvantage than before. However, prices remain high, and run/recharging times can still be frustrating.

Air: The drive in an air impact wrench is a much simpler than the motor in an electric model, which makes the tool easier to maintain and less prone to failure. It's not unusual for one to last decades. Air impact wrenches are also quite a lot lighter, which makes a big difference if you're using one for long periods, and considerably cheaper, though there is the cost of a compressor to consider.

Air impact wrenches often produce more torque than electric models, too. In the past, these tools had little or no control and were criticized for being too powerful for home use. Fortunately, that's no longer the case. The variety of tools available and the controls provided mean you have the same versatility as you do from electric tools.

All that said, an air impact wrench is not for everyone. If you're constantly moving from one place to another, the alternatives are more convenient. However, if you usually work in the same garage or workshop, these tools have some impressive advantages.

A little oil is the only maintenance an air impact driver needs on a regular basis. It’s a small task, but it's important.

Air impact wrench features

Torque: You'll often see two torque figures: nut-busting (also called breakaway) torque and maximum torque, given in foot-pounds (ft-lbs.). The former is invariably the headline number and suggests that a higher torque is available for loosening difficult nuts. That may be true, but unfortunately there's no industry standard for measuring it. In truth, it's a bit of a marketing gimmick, so if actual torque output is important to you, focus on maximum torque.

You don't necessarily want the air impact wrench with the highest torque rating. You need the one that matches the tasks you have to perform. That could mean 250 ft-lbs. is sufficient. You don't always need 1,000 ft-lbs.

Settings: You can alter the torque output on good air impact wrenches. Sometimes this is a single reverse setting – because you just need to get the nut off – plus two or three forward settings, which reduces the risk of overtightening. Top-end machines have three reverse and three forward.

Beats per minute: You'll usually find the beats or blows per minute (bpm), which is the speed of the impact action. It's not of major importance, but if you've got two very similar tools, a faster BPM is preferred.

Rotations per minute: You may also find rotations per minute (rpm), or free speed, quoted. Again, it's a secondary figure that tells you how fast the wrench can rotate while removing or attaching a fixing, but it has no bearing on the torque.

Anvil: Impact sockets attach via a square drive called an anvil. On electric models, this can be 1/4, 3/8, or 1/2 inch, but on-air impact wrenches it's usually 1/2 inch because, in general, it is transmitting more power, so you want a larger contact area.

There are two types of anvil: hog ring (friction fit, which is very fast) and detent pin (bearings provide a click fit, which is slightly more secure). In practical terms, there's little difference, although professionals tend to prefer speed.

Materials: Cheap air impact wrenches often have plastic body moldings. A rubberized grip is useful to give you a good grip, but other parts should be metal or tough composites. These tools are often poorly treated, so they need to be ruggedly built.

Hose: Be sure to check the hose size and that the connectors are compatible, particularly if you already have a compressor.


Compressor

It's important to have a compressor that can supply sufficient air for your impact wrench. Air tools and compressors have two ratings: Maximum air pressure is measured in pounds per square inch (psi), and the airflow supplied or required is measured in cubic feet per minute (cfm). Most air impact wrenches run between 4.5 and 5.0 cfm at 90 psi. In an ideal world, you need a compressor that matches the pounds per square inch and exceeds the cubic feet per minute, so you have airflow to spare.

If the cubic feet per minute of your compressor don't match the tool, you'll drain the air tank and have to wait while it repressurizes. Small pancake compressors often have high pressure (150 psi or more) but only 2.5 to 3.0 cfm. Using one of these would get frustrating because with insufficient airflow, the tool simply stops working. You then must wait until the volume in the tank builds up, and pancake compressors often don't have very big tanks anyway.

If you don't already have a compressor, a model of sufficient capacity will probably cost at least $300, but if you compare the price of a high-end electric or cordless tool, you might save that much. What's more, you then have a compressor to run other air tools, such as a grinder or airbrush, so you might save even more.


A note about lug nuts

An air impact wrench is great for taking off lug nuts – after all, it's what the pros do. However, you need to be very careful if you're using one to put them back on again. It's easy to overtighten them, and you can strip the threads or damage the studs.

Experts and auto manufacturers recommend using a torque wrench to retighten lug nuts. It's a different tool that can be set to the precise torque required to do the job properly, so there's no chance of causing problems.

EXPERT TIP

Your compressor needs to match or exceed the consumption of your air impact wrench for continuous operation. If it's less, the pressure will drop, and you'll have to wait while it builds up again.


Staff  | BestReviews

Air impact wrench prices

Inexpensive: The cheapest air impact wrenches we looked at cost as little as $40 and come with a set of sockets, too. These are perfectly good tools but often have just a single setting and relatively low torque. Low-cost tools are often noisier, too.

Mid-range: Most home mechanics will probably find what they want in the $100 to $150 range. Tools at this price are generally well made and durable and offer torque of around 600 ft-lbs.

Expensive: Spend around $250 and you're buying professional-quality tools delivering 900 ft-lbs. of torque or more. These are extremely tough tools that will deliver a lifetime of excellent performance.

Premium: Specialist air impact wrenches can cost a lot more – up to $1,500 – but unless you're running your own NASCAR team, you probably don't need to consider these.

CAUTION

Using an air impact wrench creates a lot of noise. Always wear ear protection.

Tips

  • Wear ear protection. Several health organizations state that being subjected to sounds above 85 decibels can cause permanent hearing damage. Almost all air impact wrenches exceed this – even many so-called “noise reduction” models – so always wear ear protection.
  • Wear eye protection.
  • Wear gloves. Even with soft-grip handles, the vibrations created by impact wrenches can become uncomfortable after a while. Always wear gloves, and give yourself a break from time to time.
  • Use two hands. Although some manufacturers of air impact wrenches say their tools can be operated with one hand, a firm two-handed grip is much safer. If a fixing doesn't budge, the tool can twist violently in your hands, with the potential to cause a nasty wrist injury.

Other products we considered

If you're looking for a budget air impact wrench for occasional use, the Neiko 30128A is definitely worth a look. With 600 ft-lbs. of torque, it's surprisingly powerful for an entry-level impact wrench and has good ergonomics, too. The Astro 1822 1/2" Nano has been designed to overcome the challenge of getting an impact wrench into tight spaces: this compact tool is just 3 7/8 inches from front to back. Despite its diminutive dimensions, it still produces 450 ft-lbs. of torque, and with three forward and three reverse settings, it's also versatile. The AirCat 1150 Killer Torque air impact wrench lives up to its name, delivering a maximum 900 ft-lbs. of loosening power for a surprisingly reasonable price. And at 86 decibels, it's not particularly noisy.

If you're having trouble deciding on the drive size you need, go big. You can always get adapters to reduce the drive down to smaller sizes if necessary.

FAQ

Q. What's the difference between an air impact wrench and an impact driver?
A.
An impact driver is used for screws or similar small fixings. It's most often employed where the number or length of the screws is too much for an ordinary drill or driver to cope with. An impact wrench is an extremely powerful tool for untightening or tightening large nuts and bolts. Most people will have come across one at a garage or tire dealer where impact wrenches are used on lug nuts, though these tools are also used in a wide variety of engineering situations.

Q. Is an air impact wrench better than a cordless model?
A.
In a commercial environment (and with race teams at the track), the air impact wrench is still preferred because of the consistent power delivery. There are no concerns about a battery running flat when you need it most. For hobbyists or home mechanics, it's very much a matter of personal choice. Cordless impact wrenches don't need a compressor and hose, so they're more portable, and it may not matter if you have to wait a couple hours for the tool to charge. However, good cordless wrenches can be twice the price (or more) of air tools.

Q. Can I use ordinary sockets with an air impact wrench?
A.
They might fit, but most standard sockets don't have the material strength to cope with the forces generated. The rapid impact coupled with the torque can cause them to crack or even shatter, which is very dangerous. It's recommended that you buy specific impact sockets. If the drive is the same size, these can be used with your existing ratchets.

The team that worked on this review
  • Bob
    Bob
    Writer
  • Bronwyn
    Bronwyn
    Editor
  • Devangana
    Devangana
    Web Producer
  • Eliza
    Eliza
    Production Manager
  • Kyle
    Kyle
    Writer
  • Melinda
    Melinda
    Web Producer

BestReviews wants to be better. Please take our 3-minute survey,
and give us feedback about your visit today.

Take Survey