• PCB drill bits with 1.5 mm cutting diameter, 10 mm cutting edge length, 3.175 mm shank diameter, and total length of 38 mm (approximately) • Long service life thanks to high hardness, wear resistance, strength and flexibility, and anti-deterioration properties • Made of tungsten carbide for a precise and easy drilling experience • Spiral flute design with sharp cutting edge that reduces cutting force and prevents breakage, improving drilling accuracy • High precision with sharp cutting edge, milling groove, and clean surface, allowing for fast and residue-free work • Suitable for PC boards, plastics, fiberglass, wood, and soft metals • Compatible with PCB drilling machines, engraving machines, CNC, and special high-precision drilling equipment • The set includes 20 pieces in total