Description: 3mm Micro CNC/PCB Carbide Drill Bit 3.175mm Shank Tungsten Steel Cutter For Engraving Machine Specification: Product Name: PCB drill bit Material: Carbide (Tungsten Steel) Cutting diameter: 3mm Shank Diameter: 3.175mm (1/8") Use:PCB Drilling Features: Carbide micro drill, with high hardness, high wear resistance, high strength, resistance to bending, anti-impairment and long tool life. Cutting edge strictly symmetrical: beneficial and efficient cutting, avoid offset drilling.