Drill diameter: 0.3-1.2mm, shank diameter: approx. 1/8: 3.175mm. Tungsten carbide spiral tip drill bits with cutting edge, reduce cutting pressure and prevent bit from breaking, improve drilling accuracy. Ideal for circuit boards, plastics, fiberglass, wood, soft metals, etc. Carbide rods and tungsten steel rods, with high hardness, high resistance to wear, high strength, resistance to bending, anti-tampering and long tool life. Total length 38 mm. Package Contents: 10 x Carbide PCB Drill Bits with Protective Case. Features: p> - The drill has a large debris throwing space for the lowest resistances and remains stationary during the throwing of debris - The drill bits are made with high quality materials and a fine grinding process so that the cutting edge is sharper, the cutting pressure is reduced, less breakage phenomena during drilling and hole quality in the wall are improved. -Cutting edges prevent partial formation of holes to ensure quality. Features: Cutting diameter: 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.5mm, 2.0mm , 2.5 mm. Shank diameter: 3.175 mm Total length: 38 mm. Contents: Pack of 10 tungsten carbide micro drill bits.