1mm Diamond Glass Jewellery Drill Bits Tipped, 1mm Diamond Coated Lapidary Drill Bits, Solid Bits Needle, Agate Drill Bit for Jewelry Agate, 20pcs/Pack

Material: Lapidary drill bits made from diamond powder, high-quality, precise and sturdy to use Applications: Drill bits is idea for drill holes on the jewelry, ceramic, jade, agate, glass, amber and semiconductor materials etc Diamond Coated Lapidary Drill Bit: The higher speed of drilling machine, the better effect of drilling bits Instructions for Use: The speed of drilling machine need to be reached 2000 RPM when you use our drill bits to drill holes.please use cold water during the drilling hole operation Precautions: If you use the drill bit for many times, it will not be very sharp than the first time using.You could cut a little the top of it with plier, it will become sharp again