Conical countersink, hexagonal shank For countersinking boreholes for flush screw connections in wood, non-ferrous metal, and plastic Product advantages90° countersink angle for preparing flush screw connections with flat-head screwsSpecial geometry with 3 cutting edges for smooth running and fast progressRadially back-ground cutting edges for clean countersinking without burrs and high cutting performanceTechnical data Number of cutting edges: 1 Countersink angle: 90° Shank design: Hexagonal shank AF 6.35 mm (¼") Direction of rotation: Clockwise Materials: Tool steel Instructions for use When used on metal, always first create a dimple with a center punch or pilot drill the hole and always use cutting oil.