Self-Drilling Screw - Indented Hex Washer Head - Black Oxide Steel - 5/16"-12 Thread - 2" Long - #3 Drill Point - Pack of 600

Self-drilling screws are efficient because they eliminate the need for a pilot hole, tap their own threads, and fasten materials in a single operation. The hex head washer 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. Indentation on the surface of the head is preferred for applications involving power-driving tools. The external hex drive is designed to be used with a ratchet. Black oxide steel offers mild corrosion resistance and essentially has no risk of hydrogen embrittlement.