DeWALT DCF961N 18v Brushless 1/2" Torque Impact Wrench, Bare Unit
Extremely highly praised by reviewers and tradesmen alike, this high torque impact wrench from DeWalt's 18v XR range has 1,632Nm of fastening torque and 2,373Nm of breakaway or "nut-busting" torque. It has a feature which some reviewers have nicknamed "vtec mode", whereby there is a fast ramp up of additional power. If you use the impact wrench at full power for more than approximately 4 seconds, this mode kicks the impact rate up even higher. Torque curves demonstrated in this mode have shown that as soon as this happens, the machine is at about 85% of the maximum power. This is in contrast to virtually all others on the market, where the torque ramps up slowly, only producing 85+% of its power after a sustained impact of 10-15 seconds. What this means in practice is that if the DCF961 enters the higher power mode for a few seconds and isn't breaking loose the fastener, you can be confident in knowing that other avenues are needed, such as the application of heat.
The previously mentioned 4 second delay before full power is delivered is there because DeWalt know that the majority of the time, most fasteners will be broken free within the first 2-3 seconds. This reduces the vibration to the user unless the extra power really is needed. Another way in which vibration is reduced is what DeWalt call Batteryguard. This allows the battery and main electrical terminals to float while high vibrations occur, not only reducing vibration inertia to the user's hand, but also protects the battery from heavier vibrations.
Output Power: 870 Nm
Max No Load Speed: 1,200 rpm
Max Impact Rate: 1,890 ipm
Max Fastening Torque: 1,626 Nm
Max Breakaway Torque: 2,373 Nm
