Deep recess to prevent 'cam-out', giving a precise and positive drive control on every screw. Ribs under head for improved countersinking and to give a smooth and flush finish, also prevents splitting and material damage. Coated with a high-molecular polymer lubricant that reduces the insertion torque by up to 52% and increases rust protection up to 20 times longer than a standard zinc plating. Classic thread gives an ultimate performance and an exceptionally high pull-out resistance. Patented twin cut technology for rapid pick-up and reduced timber splitting.