100 Pcs 400Grit Diamond Grinding Round Head Rotary Drill Bits

diamond coated head. Wear-resistant, close to the sand surface, not easy to fall off, maintain sharpness, long wear. Its surface can be cleaned and restored to regain its original shape by using a dressing stone. Can be installed on the electronic grinder, hanging mill and hand electric drill (not included here). Used for sculpturing, dressing, precision grinding and internal grinding carbide in ceramic, glass, precious stone, alloy and many other abrasive materials. Adding water when use the Diamond grinding head  is good, can improve the sharpness and the life of the grinding needle.