Taper Shank Drill Bits Specification: 4-12 mm (4, 5, 6, 7, 8, 9, 10,11,12mm) 4-16.5 mm (4, 6, 8, 10, 12, 14, 16.5mm) 4-20 mm (4, 6, 8, 10, 12, 14, 16, 18, 20mm) 4-32 mm (4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32mm)