DEWALT DCF921H2T 18v Brushless Compact Impact Wrench with 2x5ah Powerstack Batteries

Cordless Impact Wrenches are used for undoing and tightening bolts when no other tool can provide enough force. Therefore, you need to choose an Impact Driver which has the right level of power for the work it will be doing. This is measured by torque, which is then measured in Newton-metres (Nm). The higher the torque, the more power you have at your disposal.
Impact wrenches can use extra power to undo particularly troublesome nuts. This is known as ‘Nut-busting torque’ and the machine will apply it automatically. The more power a machine has, the more torque it can generate. As an example, some of the 12v Impact Wrenches in our range generate a Nut-busting torque of 290 Nm but the new 40v tools can produce up to 2,050 Nm of Nut-busting torque.
Cordless Impact Wrenches are extremely powerful, so be aware of the risks of bolts shearing off or material becoming damaged during use.

Brushed motors use carbon brushes to transfer power from the fixed part of the motor to the rotor. This creates a reliable and relatively inexpensive motor, but brushed motors do require regular maintenance, in order to either clean the brushes or replace them as they wear out. A brushless motor, by contrast, uses a magnet mounted on the rotor to generate the power and electrical switching to perform the function carried out by the brushes. The additional complexity of the motor’s working means that brushless motors are usually more expensive than brushed.
However, eliminating the brushes also eliminates internal friction and maintenance, meaning that brushless motors offer both increased power and a longer working life. Brushless motors also generate less heat and noise and so, on balance, are considered superior to brushed motors.

Our range of Cordless Impact Wrenches starts with 12v machines, but the increased power and relative affordability of 18v tools means this has become the industry standard, particularly as the 18v machines offer much more power without a huge increase in tool size. Professionals who need more power from their Impact Wrench for working on site could also consider the 40v XGT range from Makita.