Timberline 608-114 Quick Release Countersink for No.8 Wood Screw Size by 7/64-Inch Diameter by 3/8-Inch Carbide Tipped Hex Shank 1/4-Inch Hex Shank Design for Quick Release For No.8 Wood Screw Size Cutting Diameter 7/64-Inch, Countersink Diameter 3/8-Inch 1/4-Inch Hex Shank Carbide Tipped, Professional Quality