Air impact wrenches vs cordless impact wrenches — which is better?

Differences Between Air & Cordless Impact Wrenches

Air impact wrenches and their cordless counterparts derive their name from the shared mechanism they use to generate the incredible torque they’re known for. This specialised design uses a fast-rotating hammer that consistently strikes the anvil with incredible force, creating short bursts of high rotational torque that is great for twisting off stubborn nuts and bolts.

The only difference between air and cordless impact wrenches is the power source. Pneumatic impacts have a motor that uses vanes that are forced into motion by air, moving the rotor and powering the tool.

Cordless and electric tools instead use a brushed or brushless motor that relies on electrical currents that shift magnetic fields around to power the mechanism.

Neither of these methods of powering the impact mechanism makes one tool inherently better than the other, but they do offer some different benefits and drawbacks.

Benefits of Air Impact Wrenches

Air tools are still the industry standard for any job that requires incredibly high torque and long work times. Here are some of the major advantages to having a pneumatic impact wrench.

Lighter & More Compact

Because the motor of air tools is slightly simpler than a cordless tool, and you’re also not lugging around a big battery, air impact wrenches are generally smaller and lighter than electric variants. This makes them good to work with for extended periods of time as well as being nicer to hold in upward positions — although the hose can cause its own problems.

Air Impact Wrenches Have More Power

The main reason you’re going to go for air over electric is for the power and torque you’re going to get out of a pneumatic impact wrench. This is because air tools have a much higher power-to-weight ratio and can convert nearly all of their input power into torque, while electric tools can only convert around 50-60% of their power.

No Charging Batteries

Once a pneumatic impact wrench is hooked up, you’re good to go in terms of power. You obviously have to take the air tank capacity into consideration when working, but for the most part you’re going to get continuous use. With cordless tools, you need to change batteries after a certain amount of work, which can slow down productivity if you don’t cycle your batteries properly.

Work Longer

Using an air compressor as a power source also means that you don’t have to worry about the tools overheating, with tools being able to work hours at a time without worrying about shutting off. Battery-powered tools often have settings that will stop the tool automatically if it is about to overheat so as not to damage the battery and once they’re out of juice, that’s all she wrote.

Continuous Power

Another issue with battery-powered impact wrenches is that as the battery starts to run low on charge, you start to lose torque in the tool, meaning work will start to slow down as well. You’re also going to need to buy suitably large batteries for larger tools, as a 2.0ah battery isn’t going to cut it when you need a 12.0ah.

Easier To Handle Maintenance

Air tools certainly need filtration and lubrication to keep running, which can be a bit of a battle when these tools see constant use. On the other hand, they are simpler to maintain if something goes wrong, because they lack the electrical components that make modern cordless tools run.

Though a brushed motor tool may be relatively easy to fix in the event that there’s a failure in the tool, brushless motors are more complex and have a chip in them that will likely require the tool be sent to the manufacturer if it breaks on the job.

Benefits of Cordless Impact Wrenches

Cordless tools have been consistently getting more powerful and reliable over the years, thanks in large part to lithium batteries and brushless motors. Here are some of the advantages offered by modern cordless impacts.

Portability

Perhaps the main reason that a lot of mechanics and auto workers are making the shift towards cordless impacts is portability and convenience.

While an air impact wrench is generally going to be lighter, you’re still going to be lugging around a hose that’s attached to your gun and you’re going to be plugged into an air compressor. The more portable the compressor is, the lower the air capacity is likely to be and the more recharge time you’ll need between bursts of power.

A cordless tool can not only move freely around a jobsite, it can also be moved around an engine or undercarriage more easily in a lot of circumstances just due to not having a hose hanging off it.

Minimal maintenance

While maintenance can be tricky on brushless impact wrenches due to the electronic components in the tool, overall maintenance is generally going to be less involved than with a pneumatic version.

Air tools require constant lubrication, either via an in-line lubrication system or through manual lubrication before and after each use. While greasing up your tools should still be part of your cordless impact wrench maintenance, it’s not as necessary as with a pneumatic.

This is because the constant air coming through the hose dries out the internal components of air tools much faster and causes a lot of metal-on-metal contact that can cause damage. This is compounded by the fact that there is a lot of dirt in air, and a filtration system will likely be needed to make sure your pneumatic impact wrench doesn’t end up with grinding particles in it.

Quieter

There aren’t too many people who would think of the word ‘quiet’ when discussing any impact wrench, but there is certainly less noise dealing with a cordless tool than a pneumatic rattle gun hooked up to a noisy compressor.

Easier To Adjust Torque Output

While you can adjust the power output of air tools, it’s not as simple as modern cordless tools. Brushless impact wrenches these days will often have torque settings on the gun and new innovations from companies like Milwaukee, with their One Key app, mean that you can alter a tool’s torque to very precise specifications.

App Compatibility

Apps like Milwaukee’s One Key and Redlink Plus not only allow for torque control, they also allow for things like tool tracking, so you can find out if your impact wrench has been nicked by someone else in the shop. They can also remind you of repair times for your tools.

These may seem like minor benefits, but cordless technology is constantly evolving, and having smartphone integration now means that as these apps expand and offer new features, you’ll be able to utilise them for various tools.

More User-Friendly

If you’re a home DIYer who needs an impact wrench for automotive purposes, chances are you already have a compressor lying around. In the even that you don’t, however, and you are just starting to build up an arsenal of power tools, then being able to pickup a cordless impact gun and a few batteries is going to be much easier than setting up an air compressor, hoses, and a pneumatic gun.

You also have a lot of other factors to consider with a compressor, such as making sure the CFM and PSI are up to the job of running an impact wrench and using the tool continuously without the compressor needing to constantly refill.

At the end of the day, slapping a battery into a cordless tool is a much simpler way to pop off nuts and bolts.

Price of Cordless Impact Wrenches vs Air Impact Wrenches

If we’re just looking at the tool on its own, pneumatic impact wrenches are going to be the cheaper option of the two, with cordless impacts often costing 50-100% more than air variants. However, this isn’t the full story when it comes to cost.

While a lot of people looking to buy an impact wrench will have an air compressor already, if you have to purchase one, as well as hoses and other accessories, that can really tip the price point in the cordless impacts’ favour.

If you’re running a business and require a large air compressor then you’re going to need an air filter and lubricator for the system, and for large industrial systems, studies have shown that air compressor systems can end up costing more to run than electrical tools.

Although batteries can last a long time, you have to consider that they can fail, which means purchasing new ones.

Overall, the better option price-wise is going to be dependent on a lot of issues, so you’ll need to decide for yourself which option will cost you less.

Which One Is Better?

While cordless impact wrenches have improved by leaps and bounds in recent years, they’re still not in a place to completely replace their pneumatic cousins — especially in industrial settings where massive torque requirements are going to require air impacts to get the job done.

If you’re working in a professional or industrial setting or you already have a decent sized air compressor at home, then a pneumatic impact wrench is probably going to be a solid option. You’re going to really benefit from the extra power and work time you’ll get out of it, without dealing with the cost of a new air compressor system.

For home DIYers or professionals working in settings where portability is more important than massive torque, a cordless impact wrench is going to be perfectly suited to the job.

At Repco, we sell cordless and pneumatic impact wrenches, as well as accessories and air compressors, so head into your local store or shop online to get kitted out for high-torque nut cracking.