Self-Tapping Screw - Type AB - Indented Hex Washer Head Serrated - Zinc Plated Steel - 5/16"-12 Thread - 3/4" Long

Self-tapping screws create their own threads but require a pilot hole. The hex washer serrated head has an external hex head with a washer-style flange attached underneath the head which creates a large surface connection area. Hex heads protrude above the surface. The externally driven head allows greater torque to be applied to the screw compared to other screws that are internally driven. The serrations provide teeth-like grooves underneath the washer that bites into the surface to resist vibration. The external hex drive is designed to be used with a ratchet. Zinc plated steel offers good corrosion resistance in applications not exposed to excessive moisture.