General description Diamond Burr Bits are designed for precision work on various materials including glass, metal, stone, ceramic, wood, and plastic. This set includes 90 pieces of 1/8-inch (3 mm) diameter bits, perfect for fine detail work such as cutting, engraving, carving, retouching, and finishing. The bits are ideal for crafting jewelry, working with beach glass, seashells, lapidary gemstones, and more. Technical specifications Quantity: 90 pieces Shank diameter: 1/8 inch (3 mm) Material: Alloy Diameter of bits: 3 mm / 0.12 inches Usage Suitable for wet drilling only; do not run dry. Start the hole at an angle for better control. Hold the drill steady and allow the tool to do the work. Other information Package includes: 90 pieces in 3 boxes of diamond burr grinding wheels.