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.PTDTIM217228