Electric vs. Air Impact Wrench: Which One Should You Choose?

When it comes to dominating rusty, stubborn, or frustratingly stuck nuts, there’s only one thing you can count on — an impact wrench! It will help you save considerable time, and you won’t even break a sweat. However, if you’re in the market for a reliable and durable model, keep in mind that there are many impact wrenches to choose from out there, and it can be pretty overwhelming if you don’t really know what you are looking for.

Luckily, this comprehensive buying guide will help you make an informed buying decision and choose whether you should go for an air or electric-powered impact wrench. But of course, that decision will be heavily influenced by two factors: the frequency of use and the type of work you do.

But let’s start from the beginning.

Types of Impact Wrenches

Corded Electric Wrenches

As you might have guessed, corded impact wrenches can only be used if you have access to a power outlet. It’s a plug-in system, meaning you’re going to be leashed around that power source. Sure, they’ll do the job, but to be honest, they’re fast becoming redundant and have zero applications in the construction and automotive stratosphere.

Why? Well, they aren’t exactly portable, and you’ll always be bound to a certain work radius (basically the length of the cord). Yes, they might be fine for small, garage-based projects, but when talking about more significant tasks that require speed and mobility, they’ll be of no use.

CRAFTSMAN Electric Impact Wrench

As a matter of fact, corded wrenches can also be a work hazard; you could easily trip and fall over the cord if you aren’t careful — not worth the risk. Cordless impact wrenches are simply much better.

No need to mention that since they are pretty much not used at all in the automotive industry, we won’t be covering them here (I’m not even sure why someone might want one honestly).

Cordless Electric Wrenches

Indeed, cordless wrenches are more comfortable to use and considerably smaller than their corded counterparts. And thanks to their battery, you can take cordless impact wrenches anywhere you want. In addition, cordless electric wrenches are far more flexible to maneuver compared to pneumatic impact wrenches. The fact that they don’t need a cord or air hose is really a big advantage. They are also designed to provide decent torque to remove the most stubborn bolts, screws, and nuts.

However, it’s essential to remember that cordless impact wrenches can quickly run out of juice and are not typically as powerful as air and corded wrenches. Still, the trick here is to buy more than one battery so when one runs out, you can just switch it and use another while this one charges.

Also worth mentioning, if you do decide to get a battery-powered impact wrench, make sure to get one with a brushless motor. Why? They are more reliable, generate less heat, and last significantly longer than other types—simple as that.

Milwaukee Cordless Impact Wrench

Pros

  • Greater portability compared to air impact wrenches
  • Added convenience and flexibility of use
  • Ideal for working in hard to reach areas

Cons

  • Don’t offer as much power as pneumatic wrenches
  • Added weight at the bottom due to the extra battery takes a little getting used to

Air-Powered Impact Wrenches

The primary difference between battery-powered impact and air-powered wrenches is that the latter’s internal hammer is powered by compressed air instead of an electric motor, providing massive torque. Air impact wrenches also have fewer components making them much easier to repair when something goes awry.

However, to use a pneumatic impact wrench you’ll also need a powerful air compressor, which can be a significant drawback for smaller garages and residential settings. The extra air hose is also a bit annoying but after all, that’s what mechanics have used for the last century or so. In short, they are reliable and are ideal in most situations, but you’ll have to buy an air compressor.

That’s why you’ll see most mechanics, factory workers, and construction contractors use air impact wrenches. Sure, they’re heavier and bulkier than their electric counterparts, but none can match pneumatic models for power and the constant air supply makes them perfect for long hours in the shop.

Ingersoll Rand Air Impact Wrench

Pros

  • Air impact wrenches provide significantly more power than electric impact wrenches (in most cases…)
  • Ideal for static work (repair shops, construction sites, etc.)
  • You’ll never have to worry about running out of juice

Cons

  • Bigger and bulkier than electric impact wrenches
  • Zero portability
  • Require an air compressor
  • Bigger and bulkier than electric impact wrenches
  • Zero portability
  • Require an air compressor

Differences Between Electric and Air Impact Wrenches

Weight

Winner: Cordless

When it comes to weight, cordless impact wrenches are clear winners here. They are designed for speed and portability and have lighter internal mechanisms—the battery makes them a bit bottom-heavy, though.

Meanwhile, air impact wrenches are pretty bulky and usually heavier. The internals are frequently made of metal, adding to the weight, and the air hose is often in the way. Still, they make up for their size by providing higher levels of torque (once again, not always the case… Battery-powered impact wrench are getting quite powerful nowadays).

Power

Winner: Pneumatic

This one isn’t that straightforward to answer, but we gotta give it to air-powered models. Pneumatic wrenches don’t rely on an internal hammer system and use compressed air to deliver the maximum torque, effortlessly unscrewing and loosening tighter nuts and bolts. Put simply, in most cases, they are more powerful than other types. Still, as mentioned above, battery-powered models are quickly catching up and it might not be the case for long.

Regardless, if you need a lot of power, battery-powered wrenches will drain out rather quickly. For tough jobs, air-powered impact wrenches still reign supreme.

Maintenance

Winner: Cordless

You guessed it, cordless impact wrenches of course—an easy win too. Electric motors simply don’t have a lot of parts to maintain. All you need to do is ensure the batteries are charged and ready. And even if the battery loses capacity at some point, you can purchase another one.

And because cordless wrenches are ideal to be used sporadically, you won’t have to worry about regular wear and tear. Pneumatic wrenches, on the other hand, can be a bit irritating to maintain. They’re bigger, need to be lubricated regularly and some internal parts may need to be replaced from time to time.

However, it’s important to mention that electric motors can’t really be rebuilt as air impact wrenches can. Replacement parts are also much harder to find so when something breaks, it’s usually simpler to just replace the whole thing.

Milwaukee M18 Fuel cordless impact wrench

Convenience

Winner: Cordless

Cordless wrenches win again here. The extra weight of air impact wrenches makes them a bit uncomfortable to use for longer periods, also causing significantly more wrist fatigue. And because they generate so much force, they vibrate a lot more too.

Meanwhile, cordless wrenches offer greater flexibility and convenience, weighing only 2-3 pounds. Finally, thanks to the more compact size, you can use cordless wrenches in harder-to-reach areas, which is not to neglect.

Price

Winner: Tie

You may be surprised, but we went for a draw on this one. Air-powered impact wrenches are usually cheaper than battery-powered ones but since you’ll have to buy an air compressor, an air hose and a reel, well they aren’t exactly cheap. Of course, you’ll be able to use that air compressor to use tons of other pneumatic tools, but the investment is still considerable.

The price range is also incredibly wide, from cheap $100 entry-level models to premium $1000 ones. Whatever you will go for really depends on your specific needs, frequency of use, and budget.

So let’s call it a tie and move on…

Overall Winner

Winner: Tie

Unfortunately, there’s no right or wrong answer here. Both come with their own set of pros and cons and are used for different purposes. For example, if you need an impact wrench for stationary jobs like working in your garage, then a pneumatic wrench might be your best bet, assuming you can install an air compressor in there. Sure, it will come with a couple of disadvantages, but there’s nothing that can beat an air impact wrench in terms of power and effectiveness.

However, if you’re looking for something considerably lighter and more portable, cordless electrical impact wrenches are the way to go. Please note that you might need a couple of batteries if you plan to use it 40 hours a week in the shop.

Auto mechanic using air impact wrench

When Should You Use an Electric/Air Impact Wrench?

Impact wrenches have a myriad of applications and can be used for various work and repair tasks. However, they’re most commonly used in the automotive sector. Overall, when it comes to cordless impact wrenches, they should be used for:

  • Working on more than one worksite (you’ll require more portability, speed, and flexibility)
  • Doing repair work indoors
  • Working in tight spaces or having to unscrew nuts and bolts in hard to reach areas
  • When you don’t have acces to an air compressor
  • If you’re using an impact wrench for the first time

If you haven’t worked with an impact wrench before, you should probably go for a cordless electric wrench as it’s handy and lighter. Master using it and then move onto bulkier air impact wrenches for more extensive jobs. Not to mention that battery-powered wrenches are the future. If you are a young apprentice just starting in the field, you may be better getting used to the battery style since this is apparently where the industry is going anyway.

Pneumatic wrenches are far more powerful than electric wrenches. Sure, nowadays, you can find cordless electric models that may come a bit close to the type of power air impact wrenches provide, but again, you’ll have to rely on batteries. Here are a couple of scenarios where you should bring out the big guns:

  • When you have to unscrew ridiculously, hell-bent nuts and bolts
  • For most automotive repair jobs
  • Working on a long-term job where portability doesn’t really matter
  • If you have a bigger budget
  • And if you actually have the room to install an air compressor

Last Words

In the end, it all boils down to two things — frequency of use and application. Impact wrenches are designed to do one thing and one thing only, removing stubborn, stuck, and seized bolts. So, with this logic, if you want to perform simple DIY tasks in and around the house or your garage, a cordless electric impact wrench will suit you best. However, if your work is more demanding, like in a professional auto repair shop, or involves removing nuts and bolts from heavy machinery all week long, go for an air impact wrench — you can’t go wrong with the old-school stuff.

Jean-Claude is an Editor at GarageSpot.com and webmaster of TheMechanicDoctor.com. He has been a certified auto mechanic for the last 15 years, working for various car dealers and specialized repair shops. He turned towards blogging about cars and EVs in the hope of helping and inspiring the next generation of automotive technicians. He also loves cats, Johnny Cash and Subarus.

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