The torque wrench has motor driven pinion /13/ meshing with satellite gears /15/, which, in turn mesh with hollow toothed wheel /20/. The hollow wheel /20/ operates with a brake mechanism, consisting of a swivelling arm /25/ with roller /23/. The arm is pivoting around point /35/. The arm is under pressure from rod /26/ loaded by spring /27/. The spring is fitted in bushing /28/, which also contains spring pressure adjusting device /26/. A sensor /34/ is resting against the arm /25/ and controls a solenoid valve which operates the stopping and starting of the motor.