Slotted indented hex washer head zinc plated needle point screw. 1/4" A.F. #8 head. Multipurpose sheet metal screw for light to medium gauge applications. 22º point pierces light gauge metal. Twin fast thread design creates faster installation speeds Application: Attaches light gauge sheet metal to sheet metal or wood. Installation: A 1/4” hex nut setter or 1/4” drive socket with torque limiting nose piece set at a minimum of 1400 RPM drive speed recommended. Do not over torque as it can cause the head to snap or stripping of the threads. Installed fasteners must penetrate a minimum of three full threads beyond the metal structure. Specifications: • Meets ASTM1 A 510 for carbon steel manufacturing • Meets ASTM B 633 for electrodeposited zinc coatings • Meets ASTM F1941 for corrosion resistance