"1. Premium Material, Made of High Quality Tungsten Steel. Used on wood, iron, steel, carbon steel, alloy steel, stainless steel, copper, etc. aluminum and other metals, as well as marble, jade, bone, etc. 2. All cutters have a 1/8 inch shank - compatible with most rotary tools and die grinders. 3. Highly recommended for DIY, craft, hobby, home repair, jewelry, lapidary use, modeling, and much more. 3. p> 4. 10 different milling tools, including: ball, cone, cylinder, needle point, cone point, etc., to meet most of your drilling needs, suitable for drilling, engraving, carving, polishing, beveling, chamfering, grooving, boring and hollowing. 5. The speed of rotary tools is generally 6000-50000 rpm , ensuring a long lifespan and avoiding any inefficiency in rotation. Ease of cutting, safety and durability. Carbide cutters (Rotary Files) are manufactured from high quality tungsten carbide steel to ensure their robustness and their durability. The carbide cutters are specially designed to cut efficiently, and the 1/8-inch shank is compatible with most rotary tools. Gift perfect and essential for DIY enthusiasts and metalworkers. Please wear appropriate personal protective equipment, such as gloves and protective glasses, when using rotary tools equipped with carbide cutters ."