These forgefix phillips baypole screws with wafer head are specifically designed for joining pvcu sections particularly in bay windows the nails have a self drill tip and are zinc plated for increased corrosion resistance and durability the wafer head distributes the load under the screw head offering a firm positive fixing in a similar way to that of a washer applicationthe large wafer head distributes the load on numerous types of pvcu sections requiring joining zinc coatings prevent oxidation