Braking device provided in a bench to check the correct operation of industrial screwdrivers, wherein the braking simulates a tightening operation of said screwdriver, comprising • a container body on the top of which a coupling protrudes, suitable for coupling with the head of the screwdriver to be tested, said coupling being connected, by means of a shaft , to a braking unit , • an electronic torque and angle detector of the shaft rotation , • said braking unit comprises a plate , rotated by the screwdriver, which is braked by suitable friction surfaces moved towards the plate by the movement of an actuator, wherein the actuator is placed below the plate and pushes upwards the friction surfaces to the lower surface of said plate, while on the upper surface of the plate contrast surfaces are provided, which cooperate with the friction ones to brake the plate, characterised in that the movement of said actuator is realized by at least one electronically controlled piezoelectric element and the device comprises means for compensating the clearance due to production tolerances and consumption of the lining of the friction surfaces, said means being positioned near the base of the container body and including a rotating plate moved into rotation driven by a suitable motor and a disk coupled with said rotating plate, said disk moving vertically and abutting with its flat upper surface on the base of the actuator, the upper surface of said rotating plate and the lower surface of the disk being shaped in such a way that when said rotating plate is driven by the motor, said surfaces of the plate and of said disk come into contact with each other and said disk is lifted upwards, thus raising the actuator upwards into the direction of the friction surfaces. • a container body on the top of which a coupling protrudes, suitable for coupling with the head of the screwdriver to be tested, said coupling being connected, by means of a shaft , to a braking unit , • an electronic torque and angle detector of the shaft rotation , • said braking unit comprises a plate , rotated by the screwdriver, which is braked by suitable friction surfaces moved towards the plate by the movement of an actuator, wherein the actuator is placed below the plate and pushes upwards the friction surfaces to the lower surface of said plate, while on the upper surface of the plate contrast surfaces are provided, which cooperate with the friction ones to brake the plate, characterised in that the movement of said actuator is realized by at least one electronically controlled piezoelectric element and the device comprises means for compensating the clearance due to production tolerances and consumption of the lining of the friction surfaces, said means being positioned near the base of the container body and including a rotating plate moved into rotation driven by a suitable motor and a disk coupled with said rotating plate, said disk moving vertically and abutting with its flat upper surface on the base of the actuator, the upper surface of said rotating plate and the lower surface of the disk being shaped in such a way that when said rotating plate is driven by the motor, said surfaces of the plate and of said disk come into contact with each other and said disk is lifted upwards, thus raising the actuator upwards into the direction of the friction surfaces. <EOS>