These forgefix general purpose pozi screws with round heads are zinc plated finish for increased durability they are versatile screws suitable for use in and with many materials applicationideal for use in many ironmongery electrical and plumbing applications can be used with various screw cover caps 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