Specifications:Type: Countersink Drill BitMaterial: High Speed SteelCoating: Nano Blue CoatedCutting Diameter: 6mm 8mm 9mm 12mm 16mm 19mmShank: 1/4" hex shank.Degree: 90Flute: 5Application : ideal for the wooden plank, fiberboard, particle board, plywood, plastic, aluminum board ,etc.