GRK Fasteners RT Screw, Thread Size: #9, 3-1/8 in L, Thread Type: Reverse, Head Type: Trim, Drive Type: Star, Steel, Package Quantity: 1900 BX, Thread Length: 2.087 in, Drive Size: T-15, Applicable Materials: Composite, Wood, Shear Strength: 425 lb, 576 lb Tensile Strength