Type 17 super-sharp screws with reduced pre-drilling requirement. Self-countersinking cutting nibs with flat head for clean finish. Deep, sharp serrated threads cut through fibrous material, reducing torque required to drive the screw. Next generation lubrication system requires almost half the torque to drive over conventional screws. Knurled shank ribs reduce further the installation torque required. Helps prevent wood splitting, cleans the hole and prevents jacking when joining two pieces of timber. Star drive recess reduces cam out and end load. Twice the drive torque of pozi or square drive, eliminating spinning and fastener damage. Recess sizes T10 to T30 match screw torque requirement. Optimised thread lengths prevent cross threading and jacking, pulling wood together first time.