In operation, a rotating mass is accelerated by the motor, storing energy, then suddenly connected to the output shaft (the anvil), creating a high-torque impact. The hammer mechanism is designed such that after delivering the impact, the hammer is again allowed to spin freely, and does not stay locked. With this design, the only reaction force applied to the body of the tool is the motor accelerating the hammer, and thus the operator feels very little torque, even though a very high peak torque is delivered to the socket. (This is similar to a conventional hammer, where the user applies a small, constant force to swing the hammer, which generates a very large impulse when the hammer strikes an object.) The hammer design requires a certain minimum torque before the hammer is allowed to spin separately from the anvil, causing the tool to stop hammering and instead smoothly drive the fastener if only low torque is needed, rapidly installing/removing the fastener.

The Milwaukee 2763-22 M18 is one of the best designs on the market today in terms of powerful and capable tools, which is why it made our cut for premium choice. The device is capable of generating an impressive 700 ft-lbs of maximum fastening torque and up to 1100 ft-lbs of nut busting torque. It makes innovative design and simplicity merge in a beautiful combination with the thoughtfulness put forth by the manufacturers and helps to make socket changes easier with its ½ inch anvil.

DeWalt’s 20-volt 880 Lithium-Ion cordless impact is a 1/2-inch drive job with a whopping 400 foot-pounds of torque rating. This tool has a variable-speed trigger with an electric brake; an ergonomic handle provides added control and comfort. It even includes an LED light with 20-second delay, providing greater visibility when working in dark areas. See the Summit Racing catalog for more info. (Image/Summit Racing)
Across the board, the Bosch HTH181 wins for being the most ergonomic, and this was almost unanimous from our users. Milwaukee’s Gen2 (2767) and Ingersoll Rand’s W7150 tied for second in ergonomics. The Ingersoll Rand is also the lightest of the bunch, weighing just 6.88 pounds with the 5.0 Ah battery. Bosch and DeWALT followed in a close 2nd and 3rd, at only 7.04 and 7.10 pounds, respectively. The heaviest tool in the batch is the Matco Tools at 8.02 pounds, with the 4.0 Ah battery.

crow's-foot spanner	A wrench that is used for gripping the nuts on the ends of tubes. It is similar to a box-end wrench but, instead of encircling the nut completely, it has a narrow opening just wide enough to allow the wrench to fit over the tube, and thick jaws to increase the contact area with the nut. This allows for maximum contact on plumbing nuts, which are typically softer metals and therefore more prone to damage from open-ended wrenches.	common

Yet another design uses a rocking weight inside the hammer, and a single, long protrusion on the side of the anvil's shaft. When the hammer spins, the rocking weight first contacts the anvil on the opposite side than used to drive the anvil, nudging the weight into position for the impact. As the hammer spins further, the weight hits the side of the anvil, transferring the hammer's and its own energy to the output, then rocks back to the other side. This design also has the advantage of hammering only once per revolution, as well as its simplicity, but has the disadvantage of making the tool vibrate as the rocking weight acts as an eccentric, and can be less tolerant of running the tool with low input power. To help combat the vibration and uneven drive, sometimes two of these hammers are placed in line with each other, at 180° offsets, both striking at the same time.
The Milwaukee 2763-22 M18 is one of the best designs on the market today in terms of powerful and capable tools, which is why it made our cut for premium choice. The device is capable of generating an impressive 700 ft-lbs of maximum fastening torque and up to 1100 ft-lbs of nut busting torque. It makes innovative design and simplicity merge in a beautiful combination with the thoughtfulness put forth by the manufacturers and helps to make socket changes easier with its ½ inch anvil.

Next, shoppers need to consider the source of power for their wrenches. The most common power source for impact wrenches is compressed air. This provides lower torque capacity than their electric powered counterparts. Electric impact wrenches are commonly used in automotive-repair situations, and they can be 12-, 18-, or 24-volt DC powered. Cordless impact wrenches are also available. Finally, an industrial impact wrench may use a high-speed hydraulic motor. Almost any mechanic's shop you visit will have an impact wrench or two to use, and they are more likely to be electric-corded models or air-powered models.
Regardless of the style of cordless impact wrench that you choose, or what its socket size is, the most important feature to consider is how much torque it generates. When performing a cordless impact wrench comparison, look at the maximum torque that each one is capable of creating. Many of the best cordless impact wrenches feature multiple torque settings making them much more versatile than those with only one torque setting. Setting he torque down only to what’s needed lets your battery work longer and prevents overtightening.

I`m an old fart that started wrenchin when replacing plugs and points was mandtory every 6 months or so. The introduction of battery powered impacts did not impress me at first but the stuff Milwaukee makes is unreal. They now have a big boy I`ve heard twist an unreal 1100 ft lbs!! All there stuff is great, and one battery and “one key” (for tracking) is like si-fi stuff to this old fart. I cant wait till they come out with a 18volt jack with built in jack stand.


The Goodyear 24V is a solid device - one of the best on the market. You’ll love the variable speed trigger that allows you to have greater control over what you do. You’ll be able to work safely and efficiently thanks to the measures put in place by Goodyear. The machine is strong, durable, and built to last. It comes with heavy duty gears that are treated for heat and designed to work effectively over prolonged periods of time. The device also comes with a forward and reverse setting, allowing you to quickly tighten or loosen nuts and bolts while you’re on the job and quickly move on to the next task at hand.
Wrench is a full service auto repair shop without the shop! Our mobile mechanics service all types of cars and trucks, offering everything from oil changes and tune ups to brake jobs and no-starts. Our ASE certified mechanics can perform most jobs right in your driveway or at your parking spot at work giving you the freedom to spend your time on more important things.
Strong compact lightweight and forceful this 20-Volt cordless Strong compact lightweight and forceful this 20-Volt cordless impact wrench fits into tight spaces and delivers a robust 1560 in. lbs. of maximum torque to power through tough fastening jobs on masonry metal and wood. Get huge savings with this package that includes two 20-Volt lithium-ion batteries (4Ah) charger and ...  More + Product Details Close
×