Lexicon DIY-Knowledge

Schlagschrauber, Drehschlagschrauber

Atornilladora de impacto

Boulonneuse

An impact wrench is a power tool used to tighten and loosen screws, nuts, bolts and the like. An impact wrench is equipped with a rotary impact mechanism and has therefore little torque build-up. It can be used for clockwise and counterclockwise rotation.

Unlike drill/drivers, impact wrenches have no mechanical torque adjustment. The V-groove impact mechanism is a mass-impact mechanism which tightens screw connections with two impact pulses per revolution. Rotary-impact screwdrivers are recommended for heavy-duty screw connections, they function without restoring torque build-up and with average torque accuracy. Substantial, but temporary hammering noises are unavoidable. The required torque reduction is obtained by using torsion rods or by changing the motor speed (electronic control) or by changing the impact duration.



Impact wrenches with universal motors

are available with various graded tightening torques, for screws

- to 18 mm Ø and a tightening torque of 250 Nm

- to 24 mm Ø and a tightening torque of 600 Nm

- to 30 mm Ø and a tightening torque of 1000 Nm



Impact wrenches with rotary current asynchronous motors running at increased frequency are available as tools with in-line grip, central handle bar, D-Handle or star handle and for screws

- to 8 mm Ø and a tightening torque of 20 Nm

- to 10 mm Ø and a tightening torque of 40 Nm

- to 12 mm Ø and a tightening torque of 80 Nm

- to 16 mm Ø and a tightening torque of 190 Nm

- to 22 mm Ø and a tightening torque of 350 Nm

- to 30 mm Ø and a tightening torque of 1000 Nm

A special timing device allows the operator to change the impact duration as basis for the obtainable maximum torque. The device is set to the idling current of the wrench and triggers the time measurement when it registers increased current flow due to the increasing tightening torque.



Impact wrenches with air motors

can usually have their impact force adjusted in several steps. The torque reduction is obtained by reducing the air flow. A machine series is available with the following torque ratings and for screws

- to 10 mm Ø and a tightening torque of 50 Nm

- to 20 mm Ø and a tightening torque of 350 Nm

- to 24 mm Ø and a tightening torque of 500 Nm

- to 27 mm Ø and a tightening torque of 700 Nm

- to 33 mm Ø and a tightening torque of 1500 Nm

- to 36 mm Ø and a tightening torque of 2200 Nm

Impact wrenches powered by compressed air feature right/left rotation and are available with pistol, central and d-handle grips.