Self-Drilling Screw - Hex Washer Head - Zinc & 1,000 Hour Coated Steel - 1/4"-20 Thread - 1-1/2" Long - #4 Drill Point - Pack of 1000

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. 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. This finish has been salt spray tested for up to 1,000 hours of corrosion resistance.