Used for stitching metal or attaching to metal. A pre-drilled hole is required. Flange head gives an aesthetic finish whilst increasing the clamping ability of the screw. 60° self-tapping thread for ease of insertion. Manufactured to BS 4174:1972. Gauge: 8. Length (inch): 1. Thread Dia. (mm): 4.2. Length (mm): 25. Head Type: Flange. Recess Type: Pozi. Point Type: AB Point. Driver Bit Size: PZ2. Finish: Zinc & Clear Cr3. Material: Carbon Steel. Pack contains 200 pieces.