1Multi Purpose: Rotary file bit set is widely used for polishing the impeller channel, grinding the hole to an accurate shape, also suitable for wood carving, jewellery making, welding, etc. 2Wide Application: Die grinder bit is suitable for copper, aluminum, steel, marble, wood and other materials, can also be used in machinery, aviation, automobiles, ships, etc. 3Durable Carbide: Heavy duty Rotary File Bit is made of superior carbide materials which has high strength and toughness, excellent wear and heat resistant, long lasting to use. 4Match to Use: You can use the durable carbide grinding bit tool with pneumatic or handheld electric drive tools for higher working efficiency, stable performance and convenience. 5Compact Size: Advanced carbide grinding head comes with simple and sturdy structure, small and light weight, easy and convenient to storage and transport with taking up less space.