Premium Material, Made of High Quality Tungsten Steel. Suitable for use on wood, iron, steel, carbon steel, alloy steel, stainless steel, copper, aluminum, and other metals, as well as marble, jade, and bones. All burs feature a 1/8 inch shank, compatible with most rotary tools and die grinders. Highly recommended for DIY, crafts, hobbies, home repair, jewelry making, lapidary work, modeling, and more. Set includes 10 different milling tools: ball, cone, cylinder, tip needle, conical point, and others, designed to meet a wide range of drilling, engraving, carving, polishing, beveling, chamfering, grooving, reaming, and digging applications. Compatible with rotary tool speeds typically ranging from 6000 to 50000 rpm, ensuring durability, efficient performance, and long service life. Designed for smooth cutting, safety, and reliability.