Check the listing for details. Round Diamond Grinding Bit 20mm Spherical Ball Head Abrasive Tool Shanks 6mm. Condition: New. Listed at 11.80 USD. Diamond Coated 20mm Dia Spherical Head Mounted Points Grinding Bit 6mm Shank Product Name spherical grinding ball, round grinding head, 20mm abrasive ball, diamond round burs Tip Shape Spherical / Round Ball Material Metal, Diamond Head Diameter 20mm ( Close to 3/4") Shank Diameter 6mm (Close to 1/4”) Total Length 60mm (2-3/8 ") Grit 80 (Coarse) Color Silver Tone Quantity Only 1 Piece Description: Cylindrical tip, diamond coated head. 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. We will send out your order within 1-2 days after payment has been received and cleared. We Can List Any Size & Amount Of This Product: Head diameter from 1 mm to 50 mm Welcome to Visit My eBay Store: Jewelry Tools 1