hand operated slow speed Provided with collet 0 mm to 1mm, collet 1mm to 2mm and collet 2mm to 3mm (d) PCB Print Circuit Board Carbide Micro Drill Bits Tool - Material: Carbide (tungsten steel) Diameter: 0.3mm/0.4mm/0. 5mm/0.6mm/0.7mm/0.8mm/0. 9mm/1.