Forgefix: Drywall Screw Phillips Bugle Head TFT ZP 3.5 x 42mm Bulk 1000 FORDWS42 These Forgefix Phillips, twin fine thread Drywall Screws have a zinc plated finish for increased durability. The screws come complete with a Phillips No.2 insert bit. Their Bugle Head allows the screw to sink effortlessly into the dry lining eithout the need for countersinking, which in turn minimises the damage to the surface. APPLICATION Designed for fitting dry linings to studding. Zinc coatings prevent oxidation of the protected metal to create a longer lasting finish. It does this by forming a barrier and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a fine white dust that (in contrast to iron oxide) does not trigger a breakdown of the substrate&rsquos surface integrity as it is formed. The zinc oxide, if left intact, can act as a barrier to further oxidation, in a way similar to the protection afforded to aluminum and stainless steels by their oxide layers. The Phillips