Used for stitching metal or attaching to metal. A pre-drilled hole is required. Countersunk head gives a discreet finish into pre-countersunk holes Plated in Trivalent Chromium (Cr3) Zinc 60 self-tapping thread for ease of insertion Manufactured to BS 4174:1972" Gauge: 6 Length inch: 5/8 Thread Dia. mm: 3.5 Length mm: 16 Head Type: Countersunk Recess Type: Pozi Point Type: AB Point Driver Bit Size: PZ2 Finish: Zinc & Clear Cr3 Material: Carbon SteelSize 6 x 5/8 - 200 Pieces Timco Metal Tapping Screws - PZ - Countersunk - Self-Tapping - Zinc in Clear