Like other AIRCAT tools we’ve used, the 1150 delivers unmatched performance straight out of the box. Well-built internal components and solid engineering provide consistent power and reliability. This tool will be in our shop for many years. The twin hammer mechanism in the DWMT70773L produces up to 725 ft-lbs of max torque at a free speed of 7,500 RPM. That’s plenty of fastening force to power through most stubborn bolts on heavy equipment. We also found the power smooth and consistent, not jerky like some models. Ergonomic and Lightweight Weighing just 4.2 lbs, the 2130 is easy to maneuver into tight spaces in the engine bay or undercarriage. Its compact size and included carrying case make transportation easy too. We like being able to stash it in the trunk for roadside repairs. Key Features and Specs We put the DWMT70773L to work on everything from small engine bolts to heavy equipment axle nuts. The power is versatile enough for light duty tasks but still muscles through corroded suspension joints. Air impact wrenches are neither complicated nor difficult to use, so there’s no reason amateur mechanics shouldn’t have one at home, especially if they already own an air compressor. Air impact wrenches also can drive lag bolts or perform any job that uses hexagonal fasteners.

Rotations per minute: You may also find rotations per minute (rpm), or free speed, quoted. Again, it's a secondary figure that tells you how fast the wrench can rotate while removing or attaching a fixing, but it has no bearing on the torque.Power is supplied either by an electric motor in the impact wrench or by air from a compressor. Unlike a drill, which delivers constant rotational force, the impact wrench delivers a series of rapid strikes with short pauses – these “impacts” jar a bolt or nut loose. It's a bit like hitting your standard wrench with a hammer but much more effective. The first and most common consideration when buying an air impact wrench is the size of the fastener you'll be using, as well as the torque range required to secure or remove that fastener, meaning the nut size determines the size of the drive you'll need on the tool.

As experienced auto mechanics who use air impact wrenches daily, we understand the importance of finding models that balance power, performance, comfort and durability. After testing over 20 top-rated impact wrenches on seized components, lug nuts, and other stubborn tasks, we selected the 5 best pneumatic models for automotive work. Our MethodologyWe rely on DEWALT power tools daily for their performance and reliability. The DEWALT DWMT70773L air impact wrench meets the high standards we expect from the brand. Here’s an overview: Powerful Performance It’s difficult to imagine the immense torque (twisting force) an air impact wrench can apply, but here’s an example. A nut that is “hand tight” requires pressure of about 2 pounds per square foot, which is usually expressed as “2 ft.-lbs.” The best air impact wrench multiplies that energy more than 500 times. Tough jobs like loosening lug nuts, in which an extension bar on a standard wrench can prove insufficient, are a breeze for a good air impact wrench. You won’t find a pro auto shop without one, and they’re also used in engineering and construction.