Specification:Product name: Countersink Drill BitMaterial: Drill bit: high speed steel 4241, Chamfer: Carbon steelColor: BlackOptional Size: 5#:1.98mmx 50mm(length Approx. )6#:2.38mmx 55mm(length Approx. )8#: 2.78mmx 60mm(length Approx. )10#: 3.175mmx 63mm(length Approx. )12#: 3.56mmx 65mm(length Approx. )Suitable for: carbon steel, thin iron plate, insulation board, PVC board, wood board, etc.Quantity: 1pcPackage Includes:1 × Drill BitNote:1.Transition: 1cm=10mm=0.39inch.2. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness.3. Please allow slight manual measurement deviation for the data.