GRK Fasteners #9 X 2-1/2 In. Star Drive Trim-Head RT Composite Exterior Trim Screw (408-Pack) 16101 - The Home Depot

From the Manufacturer GRK Trim RT Composite screws have the smallest screw head available with lengths from 1-1/4-Inch to 5-Inch. Most material splitting is prevented because of the Trim head screw's exceptionally small head and the W-cut thread design. GRK has modified its innovative FIN/Trim head screw to include reverse threading under the head to help it disappear beneath the surface of composite deck material, reducing or eliminating the dimple that sometimes appear in composite decking. Use GRK Bit T-10 Self-Tapping W-cut thread design Zip-Tip Patented Climatek coating