High Work Effenciency: Long service life and High durability. 200 times more than the small wheel durability.Processing all kinds of metal(including all sorts of hardened steel) and non-metal (such as marble, jade bone). Preminum Material: Rotary burr sets are made of high quality tungsten steel, can be used to process: iron, steel, carbon steel, alloy steel, stainless steel, copper, aluminum and other metals, and marble, jade, bone and other non-metal. Processing hardness up to HRA85. Shank diameter: Shank diameter:3mm, Shank Length: 35mm, Cutting edge diameter: 6 mm,total length: 50mm. Tungsten Carbide Use: Tungsten Carbide (10 times higher than the durability of high speed steel cutter). Rotary Burr, High micro hardness,high abrasion resistance,good toughness. Widely Application: Rotary burrs are suitable for polishing metals and plastics, jewelers, lapidary use, hobbies, crafts, craft modeling, home repair and so much more.