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Anyone who has spent even just a little bit of time tinkering with their car may have experienced a home mechanics’ worst nightmare – the dreaded jammed bolt! Whether that bolt rusted in place or was simply tightened by the Incredible Hulk, a bolt that won’t budge can result in anger, broken tools, shredded palms, and the kind of language they do not teach you in Sunday school.
Enter the air impact wrench, which is also known as an air impact driver. This little tool puts phenomenal levels of power into your hands and allows you to undo (and re-do) bolts super quickly. They are a bit of an investment in terms of initial price as well as the infrastructure they require to operate, but it’s worth it.
In this guide we look at the best air impact wrenches on the market and help you decide which one might be the best for your needs.
The Best Air Impact Wrench
If you want to know the stand-out feature of this pneumatic wrench, the clue is in the title. This tool is designed to kick out an incredible power level, and when AIRCAT calls this product a “Killer Torque” impact wrench that’s not an empty brag.
A shade under 1,300 ft-lb (foot – pounds) of loosening torque is a power application that should loosen even the tightest or rustiest bolts. This is backed up by up to 1,400 BPM (Blows Per Minute) for an impact wrench of truly impressive power. This is in part due to the upgraded internal rotor, a full 15% bigger than on the previous version of this model.
1,295 ft-lb of Loosening Torque
15% Larger Rotor
- Weight4.63 Pounds
Ingersoll Rand has been producing power tools of various models and designs for over a 100 years. It has learned a thing or two in that time, such as how to make a top-quality air wrench. This model, the 231C, has been on the market for 25 years, and it has a very attractive classic design.
It has some useful features backing up that design, too. 600 ft-lbs of max torque may be a little lower than you will see on some other models, but it is still a respectable power output that will tackle all but the most fused, over-tightened bolts. The tool makes use of a twin hammer internal layout to deliver this power in such a small package. It is in fact less than 8 inches long and weighs less than 6 pounds.
Twin Hammer Mechanism
Easy to Use Power Regulator
Built-In Self-Lubricating Feature
- Weight6.21 Pounds
This is the second cat-related power tool manufacturer to make our list, and we’re only at tool number three. What the connection is between cats and power tools we’re not sure. What we do know is that this is a very well put together and well-designed air impact driver.
The big eye catcher is that it deploys Kevlar in its chassis construction. That’s good to see because Kevlar is pretty cool. It’s also extremely tough while being lightweight. It can kick out 1,295 max loosening torque, making this one of the more powerful models on the market.
1,295 ft-lb Loosening Torque
Well Placed Exhaust Pipe
Kevlar Body Construction
- Weight5 pounds
Next we have this air impact driver from Campbell Hausfield. With a reasonable price tag this is certainly one of the cheaper models to make the list. Despite that low price tag, Campbell Hausfield has managed to squeeze a lot of useful features into this well-designed tool.
For one thing it is tiny, weighing in at 4.4 pounds. When combined with the ergonomic soft grip handle, you are looking at a tool that is a delight to hold and will not fatigue your arm or hand even over prolonged periods of usage. There is a 3 speed power selector too, so you have a reasonably useful level of power control over the torque output.
Max 550 ft-lbs of Torque
3-Speed Power Regulator
Lightweight and Comfortable Design
- BrandCampbell Hausfield
- Weight4.4 Pounds
When you are creating a list of power tools, it is almost a foregone conclusion that the famous yellow and black DEWALT logo will appear sooner or later. The reason for this is simple: it just makes good quality tools for a reasonable price, which is exactly what we have here.
This is a mid-range product with a mid-range price. 650 lb-ft of max torque is produced from this tool. Again, this is less than you will see on higher-powered devices, but it is more than you will get with many others. A twin hammer mechanism is mounted inside, and it has a simple-to-use power adjuster dial. It’s also neat that the direction button is mounted just behind the trigger. That allows you to switch rotation direction with only one hand.
Max 650 ft-lb Output
One Hand Operated Direction Switch
DEWALT Build Quality
- Weight5.25 Pounds
This heavy-duty piece of equipment is a great addition to any handyman’s tool collection. With its unrivaled impact and impeccable torque, the PORTER-CABLE Impact Wrench is in a class of its own. One of its best features is the 7.5-amp motor that is embedded within it. This high-powered component makes it completely suitable for all the heavy-duty applications it can be used for. Yes, it is a little on the heavy side, but that is a little price to pay for the power that this device can deliver. In addition to that, it is equipped with 450 ft. lbs of torque, which comes in handy for the installation and removal of heavy fasteners. All this points to the fact that this is a heavy-duty piece of equipment that gets work done.
Strength is not all it has on its side. For fast speed applications it offers up 2,200 rotations per minute and 2,700 blows per minute. The crowning glory here is the forward/reverse rocker switch, which is quite convenient. All in all, this product offers up unbelievable consistency every single time.
It has a ½ inch hog ring anvil for easy socket changes
The wrench is designed for heavy-duty applications
Equipped with a forward/ reverse rocker switch
Torque on the hands, while it is being operated, is minimal
Has a sturdy build and is relatively easy to use
Fitted with a 7.5 amp motor
- Weight7.5 pounds
Next up is a model from Chicago Pneumatic, and boy does it bring the power! It brings up to 922 ft-lb of torque power to be precise. That is probably more power than many at-home mechanics are really going to need – but heck, you are certainly covering your bases power wise with this tool.
It’s claim to be the most powerful impact wrench on the market is not quite true, as we have products on this very list that can crank out a little extra torque. Its claim to being one of the lightest definitely does stand up though. The total unit weight of 4.4 lbs is very low, especially considering the power it can crank out.
3x Power Settings
- BrandChicago Pneumatic
- Weight4.4 Pounds
The first thing to note is that this is a premium tool and potentially one of the best air impact wrenches on our list. It also carries a premium price tag, ladies and gentlemen, so say hello to the most expensive item on our list. But what are you getting for all that money?
Power. Raw power. 1,350 ft-lb of torque power, to be precise. Yes, it is expensive. It’s also clearly the most powerful. That power is controlled across four settings, whereas most of models only have up to three. The extra power setting is required for more accurate control of such a high level of torque output.
Max 1,350 ft-lb of Torque!
Compact & Lightweight
4x Power Settings
Titanium Hammer Case
- BrandIngersoll Rand
- Weight4.63 Pounds
Following the most expensive item on the list, we have the cheapest. This model from ACDelco is quite affordable. Tools of this type represent phenomenal value. But are you missing out on anything to get that price point?
Well, yes. Just take a glance down at the key features, and you’ll see that this impact driver tool is only putting out a max 500lb-ft of torque. That is significantly lower than many models on this list. But not everyone needs an air wrench with enough torque to rip Robocop’s leg off. If you just need a model with enough power to tackle the occasional maintenance work on a small, modern car this will probably be enough.
Great Value for Money
Up To 500 lb-ft of Torque
Tough Aluminum Housing
- Weight6.15 Pounds
Our penultimate model comes from BOSTICH. It is all in all a pretty simple and straightforward design, but that doesn’t mean it isn’t effective. It contains the twin hammer design we like to see in impact wrenches, for example. It also has an adjustable power regulator and a comfortable and ergonomic design. The casing of the tool is tough aluminum too, which is a useful design feature.
The trigger is a little small, and you may not grasp it as instinctively as with other models – it almost feels as if it has been mounted a little too low. Then there is the fact that it only puts out 500lb-ft of torque, a surprisingly low amount of power given the high-end price tag.
Simple But Effective Design
Tough Aluminum Body
- Weight5.9 Pounds
We finish up with this model from Astro. As you can see from the image, it is designed differently than the models we have looked at so far. What we have here is an extra-small, extra-compact air impact wrench. It has been designed for use in smaller areas of the vehicle – if you are working on the transmission, for example, or underneath the engine block. To help with this it measure less than 4 inches in length and weighs under 3 pounds.
It’s pretty powerful, despite it’s tiny size, and can put out up to 450lb-ft of torque. That is very impressive for such a tiny device. It also has three speed settings in both forward and reverse. It should be noted that this tool takes bit attachments of 3/8” size, which is smaller than the bits used on every other model we’ve listed.
Extra Small Size
Weighs Only 3lbs
Generates Up To 450 lb-ft
- Weight2.98 Pounds
Best Air Impact Wrenches Buying Guide & FAQ
In our buying guide, we’ll take you through the features that you should keep an eye out for when picking out the best air impact wrench for you. After that, we’ll take a look at how best to use your new tool and answer some of the most frequently asked questions about this extremely useful product.
Features to Consider When Buying An Air Impact Wrench
- Grip – This is where you’re going to hold it, after all. All the models we looked at provide a pistol style grip for control and comfort. To increase the comfort still further, look for an ergonomic grip and/or grips with soft, cushioning materials.
- Power – At the end of the day, it is all about the power. Don’t just go for the most powerful wrench out there though, as you may simply be paying for power capacity you don’t actually need. Buy enough power for what you envisage you will require.
- Sound Levels – These little beasts can be extremely loud! It is always a good idea to wear ear defenders when using a wrench. There are also models on the market designed to make a little less noise, which can be useful if your garage is in a very residential area.
Why Should You Use An Air Impact Wrench?
There are three main reasons to use an air wrench. One is speed, the second is power and the third is to pretend you are in a NASCAR pit crew whilst you work on your car. Ok, there are only two main reasons, but they are both very useful.
- Power. We’ve joked throughout this guide about rusty, fused bolts that are hard to remove, or bolts that are over tightened to the point a plain hand wrench can’t cope. It isn’t as much of a joke as we’ve made out though, and if you’ve ever been faced with a stubborn bolt that just won’t shift then you know it’s no laughing matter. The best air impact wrench is designed to put real power in your hands. It can generate more torque than you ever could with your puny human arm, and it concentrates all that power into one handheld tool. Which is pretty cool, right?
- Speed. The other big advantage is speed. Taking a wheel on and off a car – whether to repair a tire or replace your brakes – can be a time-consuming job. A lot of that time is spent wrestling with the lug nuts that hold the wheel in place. Undoing them at the start of the hob, removing the wheel, doing your job and replacing the wheel and re-tightening the nuts and bolts. That all goes a lot quicker with an air impact wrench in your armory.
Reasons Not to Use an Impact Wrench
With great power comes great responsibility, and the whole point of an air impact wrench is to put a huge amount of power (AKA torque) into your hand. Whilst you can adjust the level of power that the air wrench is going to put out, and the best air impact wrenches will boast relatively accurate torque controls, it’s simply not possible to get a completely accurate output.
If you are tightening bolts that are part of delicate machinery or which cannot tolerate either high torque or the application of sudden torque then you would be best to use a more sensitive tool like a handheld torque wrench.
Electric vs. Air Impact Wrenches
Almost all powered wrenches are either electrical (usually run on a battery) or air powered (connected to a compressor/air tank set up). Both types have pros and cons, such as:
- Pros – Easy to use and set up – they operate straight out the box. They are also cordless (if a battery-powered model) so have the mobility to be used anywhere in the garage, on the driveway or at the roadside. They are also much quieter.
- Cons – They generally lack the power of air-powered models. They can be expensive, they are much heavier and you are at the whims of a battery.
- Pros – Power. So much power! Usually, a lot cheaper too, and very simple to use with limited settings to worry about. They are also much smaller and lighter than battery operated models.
- Cons – They need an air compressor/tank rig to be set up. They can also be very loud in use.
How to Use an Air Impact Wrench
Using an air impact wrench is actually very simple. As you will have seen in the product list above, there are not a huge range of buttons and settings for these things. Hook up your wrench to your air tank and your bits to the wrench, park the car in place and away you go.
We would suggest starting with the power in the lowest setting and cranking it up as and when required. Always remember that many air impact wrenches can be quite loud, especially when you are working indoors with them. It is a good idea to use ear protectors when using your wrench.
Best Air Impact Wrenches FAQ:
Q: What is an air impact wrench?
A: An air impact wrench is a mechanical wrench that works by air pressure. What does the Impact mean in their name? Well, read on to find out.
Q: How does an air impact wrench work?
A: An air impact wrench doesn’t just work by providing more power in terms of a rotating motion (like an electric drill). Because of their high torque, they would rip your arm out the socket. Instead, a lot of the torque power is delivered via a rotating mass inside the tool. This mass releases its energy in the form of impacts that travel through the bit and into the bolt. That provides more energy to release or tighten bolts and lugs nuts, without hurting those chicken bones you call arms.
Q: What type of air compressor is needed?
A: To determine this, you need to know the recommended PSI and CFM ratings for your wrench. Then you simply need a compressor that exceeds these ratings for your tools, aiming for about 1.5 times above the rating.
So if the impact wrench needs 5 CFM at 90 PSI, your compressor should be able to deliver 7.5 CFM at 135 PSI.
Q: What are PSI and CFM?
A: Pounds per Square Inch & Cubic Feet per Minute.
Our Top Pick
There are, as we looked at above, a range of features that you should look for when selecting the best air impact wrench to suit your needs. For us though the most important feature has to be power output. After all, this is a power tool that you are buying to provide the extra power that hand held wrenches simply can’t deliver.
Bearing that in mind then, we have to go for the AIRCAT 1150 Killer Torque Impact Wrench as the best model on our list. It kicks out a lot of useful torque power, allowing you to tackle even the most stubborn bolts quickly and effectively. It delivers that power is a small, compact and easy to hold form and as an added bonus provides all that power very quietly. Every aspect of the design is well thought out and useful and that is why it is our top pick.
- How does an impact wrench work? - HowStuffWorks