An impact wrench
is the tool you turn to when a hand wrench just won’t do. It’s also great for any time you need extra power and torque to break loose a tough nut or bolt.
They can be used to handle lug nuts on a car, heavy-duty bolts on swingsets or patio covers, and even foundation bolts. They use a powerful motor, a notched hammer and bar-shaped anvil to apply immense torque to nuts and bolts.
The motor applies a continuous, sudden twisting motion to the nut or bolt, causing it to loosen or tighten with immense force. The hammer also creates very strong concussive blows, which is why they are called “impact wrenches.”
When selecting an impact wrench, you need to consider the application and the type of power and torque needed. Some tools can be powered by air (pneumatic impact wrenches), while others are battery-powered and electric.
Cordless impact wrenches are more convenient than pneumatic models, allowing for easier portability and access to applications that would otherwise be out of reach with an air tool. They don’t require compressors, generators or hoses and can run off a standard household battery.
For professional jobs, look for an impact wrench that can accurately control its output torque. This is especially important when using the wrench on fasteners that are highly sensitive to pressure, such as wheel nuts. In such cases, some wrenches are designed to limit the maximum amount of torque that can be applied by the tool, either by incorporating a flow regulator or with the help of a reversing valve.