Constructed from top-quality Vanadium steel, these engraving bits exceptional durability and precision. for detailed work, the burs range from 0.5 to 4 mm in size(0.5/0.6/0.8/1.0/1.2/1.4/1.6/1.8/2.0/2.3/3.0/4.0mm), accommodating carving needs for professionals and hobbyists alike. Designed to fit seamlessly with any 3/32 inch (2.35 mm) shank rotary tools, these versatile burs are for electric drills, grinders, and more. They provide the convenience and flexibility needed for intricate engraving and carving tasks. for a wide range of materials including silver, jewelry, wood, and walnut, these burs are for craftsmen and artists. Whether you're a professional jeweler or a woodworking enthusiast, find these tools indispensable for your projects. Highly recommended for engraving delicate items such as olive cores, beads, , wood, and bone, as well as precious soft metals. These burs are specially crafted to handle fine details without damaging the fragile materials. Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:Silver Material:steel Size:0.5/0.6/0.8/1.0/1.2/1.4/1.6/1.8/2.0/2.3/3.0/4.0mm Package Contents: 36 x Round Shape Ball Burr Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.