Ankerbolt is a Self Tapping Anchor. Countersunk Head Grade 8.8 Zinc Plated Clear Passivated. For use in a variety of base materials. The self tapping action provides a positive anchorage in concrete, brick, stone and hollow materials. Drill hole size 6mm. Anchor length 50mm. Maximum fixture thickness 20mm. Minimum hole depth 40mm. Driver type T30 Torx. See Technical Data for Loads and Torque Settings