Gimlet point. No. 2 square drive prevents bit from slipping. Special ribs under the head countersink into material for flush seating. Serrated thread design reduces installation torque and provides superior holding power. Corrosion-resistant finish prevents unsightly rust from bleeding into tile. Specifically designed and recommended for use with fiber cement backerboard. Common applications: Bathtub/shower, countertops, floors, sink blacksplash.