Drilling the underneath the countersink screws and removing dishes at the same time. Dowels (wood plug) and lower holes are made of No. 58 x High Speed hexagonal shaft buried cone. Perfect for drilling into hardwoods. Cutting material: Wood, hardwood; Plate holes and countersunk processing; Dowel holes (embedded holes) and underhole processing; Total length: 3.1 inches (80 mm) Shank diameter: 2.4 inches (6 mm) .35 - Pre hole diameter: 0.1 inches (3 mm) - Countersunk diameter: 0.4 inches (9 mm) - Compatible models: Impact screwdrivers, electric drills - High speed steel (HSS) COD Payment, Designate Delivery Time, and Store Counter PIckup are not available. Thank you for your understanding.