These Forgefix single thread Coach Screws are Zinc plated for increased corrosion resistance. Their hex head enables higher torque capability when tightening, & to increase speed of use with socket drivers. Conform to DIN571 standards. Application: Used widely in heavier timber installations & for fixing timber to masonry. Also popular as a fixing for satellite dish installation together with a rimmed or rimless wall plug. Zinc coatings prevent oxidation of the protected metal to create