Specification: Cutting edge diameter (CED): 0.15mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm; shank diameter: 3mm / 1/8" (approx.) overall length: 38mm / 1-1/2" (approx.)Long Tool Life: With high hardness, high wear resistance, high strength, resistance to bending, anti-impairment. Made from Tungsten Carbide for precise, easy experienceSpiral Flute Bits: Tip spiral flute drill bits with sharper cutting edge, reduce cutting force and prevent drill broken, improve the drilling accuracyHigh Precision: With sharp cutting edge, milling groove and clean surface, these sets of tool work quickly and cleanly, no glitches or scrap leftGreat Use: Great for PC Boards, Plastics, Fiberglass, Wood, Soft Metals. Fit for: PCB drilling machines, engraving machine, CNC and high precision special drilling equipmentFeatures:Cutting Edge Diameter (CED): 0.15mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mmCutting Edge Length: 2.7, 4mm, 5.5mm, 7mm, 7mm, 8mm, 10mm, 10mm, 9.5mm, 9.5mmShank Diameter: 3mm / 1/8" (approx.)Overall Length: 38mm / 1-1/2" (approx.)Cutting Edge Material: Tungsten CarbideShank Material: HSS (High Speed Steel)Package Included:2 Set (20 Pcs) x PCB Drill Bits with Protection BoxDescription:1. Long Tool Life: With high hardness, high wear resistance, high strength, resistance to bending, anti-impairment. Long-lasting bits are made from Tungsten Carbide for precise, easy experience.2. Spiral Flute Bits: Tip spiral flute drill bits with sharper cutting edge, reduce cutting force and prevent drill broken, improve the drilling accuracy.3. High Precision: With sharp cutting edge, milling groove and clean surface, these sets of tool work quickly and cleanly, no glitches or scrap left.4. Great Use: Great for PC Boards, Plastics, Fiberglass, Wood, Soft Metals. Fit for: PCB drilling machines, engraving machine, CNC and high precision special drilling equipment.5. Good Replacements: Carbide PCB Drill Bits replace your CNC machines and any hand held tool. Large drill bit chip space, chip resistance, chip smooth, small drilling heat.Note: The drill bits are too tiny, so it is very fragile for handling. Please be careful and take good control of your CNC speed.