Having an impact wrench in your home garage or in a professional automotive repair shop is an absolute must if you spend a lot of time working on your car. The longer you work on vehicles, the more uses you will inevitably find for an impact wrench. Whether using them for disassembly of a vehicle, or using them to snug fasteners down before using a torque wrench to apply torque to spec, an impact wrench will make the operation smoother and quicker. The time savings at each step of the process allows you to get more done in a shorter amount of time. If you’re a professional getting paid for your time, that turns into more money in your pocket and less time on the job. Similarly, if you’re an amateur mechanic, that turns into more time enjoying beers with your friends.
When comparing impact tools for your home garage, the general concept for how they function is largely the same across brands. They drive a fastener with a repetitive hammering motion in either clockwise or counter-clockwise rotation. Impact tool shapes are most commonly found in a gun shape, but can come in variations similar to a long-handled ratchet or a hand-held ring. One major difference in the tool design is power input, specifically the input power the tool runs off of. One debate many people have is whether they should get an air powered impact wrench or a battery powered impact wrench. When it comes to air powered impact wrenches versus battery powered impact wrenches, both have certain advantages and disadvantages that lend themselves well to different types of mechanics. Below, we’ve broken down the major considerations to help you decide which type will work best for you.
Air Powered Impact Wrenches
Air impact wrenches, also known as pneumatic impact wrenches, typically have a higher torque on average compared to their equivalent battery powered counterparts. They offer an extensive torque range with some wrenches operating in the lower inch-pound range while others operate at up to hundreds of foot-pounds of applied torque. Power output can be varied depending on the compressed air pressure going to the tool. The tool will run strong as long as the air pressure stays at the upper end of the input range, but if the pressure drops the performance of the tool will follow suit. Maintenance on the air powered tools usually is just a simple drop or two of pneumatic tool oil in the hose input connector before each use. They tend to be more simplistic in design compared to battery powered wrenches thanks to the fact that they don’t contain electronics which also tends to make them relatively affordable. As their operation is completely mechanical, there are simply fewer things to break and thus they tend to be the most reliable type of impact wrench.
While air powered impact tools offer simple beneficial features, one of the disadvantages is that you need an air compressor and tank to run it. This works great if you have an existing air system in your garage, but if you need to set one up specifically to run your wrench, then you lose all of the cost benefits of the cheaper tool. Air powered impact wrenches also require a mechanical connection to your air system, so you will need a hose to move that compressed air from a secondary compressor to the tool itself. You’ll generally have a twenty-five foot hose running through the garage between the compressor and tool, and that adds an extra trip hazard across the floor to be cognizant of. Similarly, you’ll have to take the hose into account as you try to maneuver your wrench into tight spaces or when walking past objects on your shop floor so you don’t snag your hose on something.
Battery Powered Impact Wrenches
Battery impact tools can produce a variation in output torque available without the hassle of an air hose. This is perhaps their biggest advantage in that not only are they more easily positioned in tight spaces under your hood, but they are also portable so they are easily carried to a friend’s house thanks to their lightweight construction that allows them to be easily stored in a tool bag. Their simple flexibility and freedom from an externally attached hose for power makes them a great choice for home or professional garage. The torque available with the tool is dependent on the battery voltage, so a 12-volt battery may not offer as much torque as a 20-volt battery could. Beyond input voltage, battery impact tools typically have a selecting switch that you can adjust the output torque up or down depending on your needs.
One of the immediate negatives of the battery tools are the batteries themselves. They have a limited amount of charge and will eventually run out of juice. If you can wait for a battery to recharge, then this shouldn’t be a big concern. If you need continuous use of the tool, you may need to purchase additional batteries to stay active on the job. In addition, you need to be diligent about charging your batteries or you’ll find yourself without a functional wrench until you get them charged up. A lot of tool retailers offer tools with an extra battery as a set, which may be a better value with a slightly higher price than just a tool itself. Batteries will also have a lifespan after which they hold significantly less charge. Once this happens, they ultimately need to be recycled and replaced. Finally, battery powered wrenches tend to cost more as they are more complex when compared versus air impact wrenches.
When considering your specific need for an impact tool, one of your first thoughts needs to be your input power. If you’re in a garage that has an existing air compressor already installed, a pneumatic air powered tool is pretty much a no brainer. It won’t add much in additional costs beyond just purchasing the tool, which is cheap by comparison. A battery powered tool can offer more flexibility with no external attachments, but does require a fresh battery for those long nights in the garage. If you plan to run them continuously, multiple batteries will be required for those long build sessions. Extra batteries, a charger for the batteries, and a higher initial purchase price for a battery impact wrench may be hard to justify if you have an installed compressor waiting for you.
Overall, if you need portability and/or don’t have an air system available in your garage, we suggest going for a battery powered impact wrench. If you have an air system and are looking for an affordable impact wrench, we suggest trying out one that is air powered.
If you want to check out some more impact tool options, click here to see our impact tool buyer’s guide. Happy wrenching!