These Forgefix Pozidriv Self Tapping Screws have countersunk heads & are Zinc Plated for increased resistance to corrosion. They tap their own thread in to a pre-drilled pilot hole in sheet or solid material. They are single threaded to resist pull-out. Application: ideal to be used in many DIY, ironmongery, engineering, electrical & plumbing applications. Zinc coatings prevent oxidation of the protected metal to create a longer lasting finish. It does this by forming a barrier & by acti