Simpson Strong Tie F08T225WDC Self-Drilling Fiber Cement Number 8 by 2-1/4-Inch Type 410 Stainless Steel 100 per Pack Wafer head, self-countersinking nibs under the head Number 2 square drive SSBIT2-2 Number 3 Drill Point 18 Threads per-Inch .39-Inch Head Diameter