Brushless Cordless Impact Wrench Tyre

What You Need to Know About Impact Wrenches

How They Work

Unlike cordless drill/drivers and impact drivers, which excel at drilling holes and driving screws, the impact wrench is specially designed for tightening and loosening various hex-head bolts, nuts, and lag screws. It employs both rotational force (torque) and short-burst concussive blows (impacts) to deliver an unparalleled amount of power. For example, most cordless drill/drivers produce about 50 foot-pounds of torque, and the average impact driver delivers about 125 foot-pounds. By comparison, cordless impact wrenches can easily produce torque outputs of over 250 foot-pounds, which is more than enough muscle to power-drive the fattest lags and bust loose rusty, corroded nuts.

However, all that brute strength isn't very useful if you can't control the tool. Fortunately, impact wrenches are extremely comfortable to use because the concussive blows smoothly transfer most of that high-energy torque directly to the fastener, not to your hand, wrist, or arm. As a result, the twisting motion-known as reactionary torque-that you feel when using an electric drill is virtually eliminated.

Batteries: Volts and Amp Hours (Ah)

All things being equal, higher voltage will give you more power-but there are cases for lower voltage. With smaller batteries, 12-volt impact wrenches are more compact. This makes them good for smaller jobs, working overhead, or getting into tight spaces. Tools with 18 and 20 volts have less difference between them. Generally, 18-volt tools with advanced features and capabilities make them more versatile and easier to use.

Amp hours (Ah) equals the number of amps that the battery will discharge, continuously, for an hour. Think of amp hours like the volume of a gas tank-a bigger number equals more gas.