The ForgeFix Spectre™ Screws are advanced multipurpose wood screws with double countersunk heads and pozi compatible recess They have a sawtooth thread design to prevent splitting and reamer to prevent jacking The screws have a zinc yellow passivated finish for excellent resistance to corrosion The zinc yellow passivation process of electroplating is similar to the galvanised and zinc plated processes but with the addition of a yellow dye It offers an aesthetically pleasing finish