At a glance: Cordless impact wrench

Cordless impact wrenches have so far been used primarily in metal construction. Here they are optimal, because they can screw in the threaded screws quickly and finally tighten them with high torque. Your rotary percussion allows – depending on the design of the machine – very high torques, sometimes several hundred Newton meters.

However, the applied torque cannot be set or limited with cordless impact wrenches. Ultimately, it is determined by time, which the percussion mechanism acts on the screw. So that there is no overloading and breakage of the screws, the machine should be matched to the size of the screws used. In the meantime, many users use the cordless impact wrench not only for screwing in threaded screws, but also for spax screws and for drilling in wood and metal. With small wood screws (< 5 mm) a speed advantage can be achieved through the higher speed of the machine. But the force required to screw in the screw is so great, that the rotary percussion mechanism has to go into action, the speed advantage is gone again. Cordless impact wrenches also offer advantages when loosening stuck Phillips screws. Similar to the impulse function of the cordless drill/driver from Metabo, the small rotary impact impulses allow it, that the screwdriver bit can always be centered in the screw head and does not slip out. The come-out effect is prevented. The machines can also be used for pre-drilling in wood and even in metal with special drill bits with hexagonal shanks. Important: Don't fall for the thought, to convert a lightweight cordless impact wrench to a 1/2-inch external square using adapters, then use it to loosen the wheel nuts on your car. Material breakage is programmed here! (See also shopping tip box, below)

SHOPPING TIP

■ Wählen Sie einen Akku-Schlagschrauber so, that it provides the torque required for the screws they process. In the case of very different screw sizes, different machines may also be required.

■ Akku-Schlagschrauber mit 1/4-Zoll-Innensechskant eignen sich eher für kleinere Verschraubungen. But they can also be used more universally with bits and drills.

■ Für große Gewindeschrauben sollten Sie Akku-Schlagbohrer mit 1/2-Zoll-Außenvierkant vorziehen. These devices are usually more powerful and are also suitable for loosening wheel nuts. But be careful when dressing! They are usually too strong for that. With a torque wrench, on the other hand, you are on the safe side.

The more powerful cordless impact wrenches are also suitable for loosening wheel bolts. If the device is equipped with a 1/2 inch external square as a tool holder, the nut for the screw can be attached directly. Impact wrenches can also be used for drilling, when precise drilling is not important.

Cordless impact wrenches can demonstrate their advantages in metalworking. You screw in even long threaded screws at high speed and then tighten them with a strong impact.
Depending on the size and design of the machine, torques can be between 80 and 450 achieve Nm.