These forgefix hexagon nuts are bright zinc plated for increased corrosion resistance the hexagonal shape is designed to be driven by a wrench spanner and provides excellent torque when done so 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 substrates surface i