These Forgefix Spring Head Nails are a popular roofing nail for corrugated roofing. Their twisted shank assists in absorbing movement that may occur in the roofing construction. They are galvanised for increased resistance to corrosion. APPLICATION:Galvanised spring head nails are most commonly used for securing corrugated sheeting and other roofing materials.Can be used with a rubber or plastic spat washer. Galvanisation is process of applying a protective zinc coating to steel in order to prevent rusting. Zinc coatings prevent corrosion of the protected metal by forming a physical barrier, and by acting as a sacrificial anode even if this barrier is damaged.