Mainly used in theatre for fixing together two pieces of scenery which will remain together permanently, such as flats that are 'booked', or to act as a fixing between two items that are not at right angles. The two parts of the hinge will go from a closed position through 270° to its fully open position making them suitable for folding gate rostra. Takes Screw Size: No. 8 [4 or 4.5 mm]