The type 17 tip provides fast starting and resists splitting in hardwood. Coarse threads run approximately 2/3 up the shank to draw the decking tightly to the substrate. Pre-drilling is recommended near board ends to prevent splitting. #1 Square Drive - All #7 diameters and 9 x 3 1/2. #2 Square Drive - 9 x 4Simpson Strong Tie Co., Inc.