These forgefix multi purpose pozi screws with countersunk heads have a zinc yellow passivated finish for increased durability the screws are immensely popular and versatile and used in all trades including joinery electrical and plumbing also widely used in diy applications applicationsuitable for use with many materials including pvcu timber chipboard mdf and other similar types the zinc yellow passivation process of electroplating is similar to the galvanised and zinc plated processes but with