If corrosion is the barbarian horde, banging at the gates of Western Civilization to bring it down, the impact wrench if your last line of defense. When all else has failed, it is there to turn a frozen nut or loosen a rusted bolt. If it fails, you face a future of unpleasant drastic choices.
There are two basic kinds of impact wrenches on the market today, those powered by electricity and pneumatic wrenches. Pneumatic wrenches, just in case you’re confused, are impact wrenches powered by compressed air.
In general, one is better in day-to-day application. In reality, both of them bring positives and negatives to the table that you’ll want to consider before making a purchase decision.
In a perfect world, the pneumatic impact wrench is easily the best. There are good reasons why when you take your car into your local tire shop that you hear the high-pitched “Whiiir! Whiiir!” of compressed air.
It’s a lot more powerful than electricity. It will crank off even the most frozen lug nuts with ease.
Beyond that, the fact that pneumatic impact wrenches use an external power source means that they tend to last longer. The primary thing that kills tools is that the power source wears down, and when the power source is external to the tool, that means the tool just has a longer life.
The external power source has another advantage. Pneumatic drills are just cheaper than electric because you have to pay separately for what gives it its power.
A reasonable reaction to that might be to wonder whether the cost of that external power source ought to instead be a drawback to a pneumatic drill. Yes, kind of. We’ll get to that in a second.
On the flip side, some pneumatic impact wrenches get their juice from electricity, either a dedicated power cord or a battery for cordless. Objectively speaking, both of these deliver less power than a pneumatic impact wrench. The numbers just simply lie this way.
That aside, despite the strong advantages of pneumatic impact wrenches, most average DIYers will find these an attractive alternative to a pneumatic impact wrench.
Pneumatic wrenches get their advantage from the fact that compressed air can deliver more powerful results than electricity. When you factor in cordless electricity — a battery-powered impact wrench — that advantage jumps way up. But you have to have access to consistent compressed air pressure to realize this advantage.
Auto shops and tire change stores have this in the form of giant air compressors. If you have a giant open bay with plenty of space for support equipment, and you also have a ton of loose cash to burn, supporting a pneumatic impact wrench might be an easy call. If you have a home workshop with a modest air compressor and not much more than the occasional need for an impact wrench, a pneumatic model might be much too much money for what you need.
This will especially pan out as the case when you consider that connecting an impact wrench to compressed air requires long hoses to do it.
There’s a good reason why tire shops and other auto repair places use compressed air for their impact wrenches. Compressed air just offers more power. But it requires that you have reliable access to compressed air, and even if you have an air compressor at home, using that to power your wrench might require a long time to charge between uses. This is something you’ll want to keep in mind before you go this route.
Unless your lug nuts are frozen to within an inch of their lives, an electric impact wrench — including a cordless model — will probably deliver the right pressure to loosen them. Of course, you’ll want to check the torque requirements of your lug nuts and the relative power of the cordless impact wrench before buying to make sure it’s suitable. This isn’t just a more mobile option when you factor in the costs of having reliable access to lots of compressed air on hand, it’s a more affordable option.
Header image credit: Mark Hunter, Flickr
Hi there! My name is Adam and I write for HealthyHandyman. I have a great passion for writing about everything related to tools, home improvement, and DIY. In my spare time, I'm either fishing, playing the guitar, or spending quality time with my beloved wife. You'll also often find me in my workshop working on some new project!