Features:Material: tungsten carbide, high-speed steel, wear-resistant and durable.Shank: 1/8" (3mm),Length: 8/5" (40mm).Carbide burrs work with most small rotary tools such as Dremel tools and are ideal for machining a variety of materials such as wood, plastic, foam or resin models20 different tools, including: rotary burr, grinding head and rotary burr cutting tool, etc., meet most of your drilling needs, suitable for engraving, beveling, chamfering, grooving, reaming, hollowing out.The rotation speed is generally 6000-50000 rpm, which has a long service life, reduces inefficient turnover, and keeps sharp for a longer time.Use:1. Provide various forms of micro-drilled or cut parts.2. The effective length of the material is about 39mm.3.20 pcs grinding milling cutter set, including arbor.4. All equipped with 3mm diameter arbors to fit most rotary tools including Dremel.5. These 20 pcs HSS milling cutters are perfect for various jobs, such as model making and so on.6. Uses: stone carving, jade carving, grinding, polishingIncludes: 20 x HSS Routing Wood Rotary Bits