Specifically designed for fixing cement board steel dry-lining frames (max. 3.0mm). Self countersinking head for a secure and flush finish. Self-drilling point with a self-tapping thread. Exterior grade coating for superior corrosion resistance in damp or corrosive environments, when compared to standard fasteners. Organic plating withstands 1,500 hours in salt spray test Self-drilling point for fixing to light section steel (Max. 3mm) Ribs under the head for improved countersinking Fire Classification: A1" Thread Dia. mm: 4.2 Length mm: 32 Thread Length mm: 23 Head Type: Countersunk Wafer Recess Type: Phillips Point Type: Self-Drilling Driver Bit Size: PH2 Finish: Exterior Plus Material: Carbon Steel Max Drilling Thickness mm: 3.0 Timco Drywall Timber Stud Cement Board Screws PH Countersunk Wafer in Silver