General description Round cup burs are crafted from premium Vanadium steel, ensuring durability and precision. This set includes 6 pieces, each with a diameter of 2.3 mm, designed for various applications in jewelry making and lapidary work. Technical specifications Diameter of burs: 2.3 mm Shank size: 3/32 inch (2.35 mm) Material: Vanadium steel Package contents: 1 set of engraving bits (6 pieces) Measurement allowed error: +/- 1-3 cm Usage Ideal for carving silver, jewelry, wood, walnut, olive core, beads, and precious soft metals. Other information Note: Light reflection and different displays may cause the color of the item in the picture to differ slightly from the actual product.