Abstract: Method to check the correct functioning of a tightening tool, such as an industrial screwdriver, placed on a test bench. Said bench includes a plurality of hydraulic brakes (F1-Fn), to which the instrument is associated, suitably controlled by a hydraulic circuit. Each brake is equipped with measurement transducers (TR) capable of measuring the torque exerted and the angle of rotation on this brake, connected to an electronic driver card (SP), which also controls the hydraulic circuit. The bench also includes an electronic processing unit (U) which communicates with the card and which includes an adequate driving program memorized on it capable of regulating the braking capacity of the brakes through the hydraulic circuit according to a predetermined braking torque/angle of rotation curve of the brakes.