Abstract: The holding device of the present invention, facilitates the tightening of a screw joint projecting from both sides of a pair of plates. The device includes an arm which at one end thereof, features an organ for a torque transmitting engagement with a part belonging to the screw joint, and at the other end features a lateral stop which includes a cam body or eccentric assembly designed to abut against an edge of at least one plate or flange. Once the tightening operation is completed, the device is adaptable to readily disengage the arm from the screw joint.