Unslotted Hex Washer Self Drill Machine Full Thread #4Point Zinc 1000hours Salt Spray

AISI 1022 or equivalent steel: The unified thread pitch reduces friction and driving torques. Drill screws with this style thread are normally used with thicker materials, particularly when the materials being joined are thicker than a single spaced thread pitch. The reaming wings drill out a clearance hole in wood or other soft materials, then snap off when in contact with the metal surface to be drilled. The #4 point typically will drill through sheet metal from .145 to .312 inches thick