In modern houses you will find these fixings to be invaluable. The PDM self drilling plaster board fixing is a self tapping, rapid installation fixing suitable for plasterboard and rear insulated plasterboard. The PDM cuts into the plasterboard until the head is flush with the surface. Pre-drilling is not a requirement, but would certainly aid accurate positioning if desirable. Installation is with a standard Pz2 screwdriver - we recommend hand rather than power to avoid over-tightening. The sharp, self-tapping thread gives a secure, positive fixing with a high load-bearing capacity. The fixing comes with a 35mm pan head screw, but you can use wood, self-tapping and chipboard screws of 4.0mm. Not suitable for tiled plasterboard.