JINGLING 3mm 1/8" Diamond Coated Super-Thin T Head Grinding Needle Bit Mounted Point Lapidary Carving Tools Pack of 10Pcs Product use:apply to stone carving, jade carving, bone carving, egg decorating, glass carving etc. Used for sculpturing, dressing, precision grinding and internal grinding carbide in ceramic, glass, precious stone, alloy and many the abrasive materials Head Diameter:3mm;Shank Diameter: 2.35mm (3/32") Product Name:Diamond Mounted Point; The Mounted Point can be installed on the electric grinder,hanging mill and hand electric drill (not included here).