[SIZE] - 1.7mm/2.1mm diameter, 16mm/20mm length twist drill bit. [MATERIAL] - Diamond-coated high-speed steel is made by spiral technology, has both toughness and hardness and is not easy to break. The drill bit is sharp and is easy for chip removal.. [APPLICABLE MACHINE] - Widely used in rotary tools such as hand drills, drill presses, flex shafts, bench drills, and hanging mills.. [APPLICATION] - Suitable for drilling small holes in glass, soft metal, sea shells, jade, pearls, porcelain, drywall, and so on. A tool used by jewelry designers to drill clean holes for making earrings, pendants, and bracelets.. [NOTICE] - When drilling, it is necessary to add cutting fluid in time to lubricate and cool down, which can get a better drilling hole wall, and extend the service life and drilling accuracy..
