TIMco 00834CCAZ Self Tapping Screw PZ2 CSK BZP 8 x 3/4" Box of 1,000. Countersunk Cross-Recess TIMco Countersunk cross recess self-tapping screws. Deep pozi sockets and a small head diameter allow for close spacing and a smooth flush finish. Used for stitching metal or attaching to metal. A pre-drilled hole is required. Features & Benefits: Countersunk head. Plated in Trivalent Chromium Zinc. 60° self-tapping thread for ease of insertion. Specifications: Diameter: 4.5mm. Length: 19mm. Quantity: 1000.