Check the listing for details. Ball Diamond 1.5mm - 6mm Grinding Burr Point Engraving Bits for Dremel Rotary. Condition: New. Listed at 1.68 USD. Ball Diamond 1.5mm-6mm Grinding Burr Point Engraving Bits for Dremel Rotary Product Information Name: Ball Diamond Bits Shank diameter: 3mm Head Diameter: 1mm-6mm Total length: 44mm Material: Boron Nitride Product features High hardness, diamond spherical grinding needles have excellent wear resistance and durability. High thermal conductivity, diamond has good thermal conductivity properties, can quickly the heat generated in the grinding process, to avoid the grinding process temperature is too high and caused by the decline in the grinding effect or deformation of the material. High chemical stability, can be used stably in various grinding processes. High precision, able to provide accurate grinding results, suitable for areas where high precision machining is required. Scope of application Mainly used for carving, metal, ceramics, jade and other materials.