A handle connectable to a screw type mechanical drive component for transmitting to the latter a first torque comprises first connection means (3) defining a constraint axis (2) for the connection of the handle to the mechanical drive component a ring nut (4) to which a second torque is manually applicable support means (5) of the ring nut (4) for rotatably supporting the latter around an axis of rotation (6) coinciding in use with the constraint axis (2) second means (7) for connecting the ring nut (4) to the support means (5) for connecting/disconnecting the ring nut (4) and the support means (5) in a mechanical and selective way so that the ring nut (4) is kinematically connected to the support means (5) when rotated around the axis of rotation (6) with a second torque lower than a threshold value and kinematically disconnected from the same upon exceeding such a threshold value.
