13 Pcs 2.35mm(3/32'') Shank Diamond Grinding Head Mounted Burr Point Set F Needle for Jade, Jewelry, Stone, Ceramic Grinding/ Carving/ Polishing Shank Diameter: (2.35mm)3/32''; could be slightly different, depending on manufacturer Can be installed on the electronic grinder, hanging mill Used for sculpturing, dressing, precision grinding Internal grinding carbide in ceramic, glass, precious stone, alloyand many ther abrasive materials. Ball shape head, diamond grinding tools for diamond and jade carving