The latest double displacement spiral in the drill bit enables drilling chippings to be removed some 30 faster and the drill achieves a higher cutting speed which protects both the drill bit and the machine the highperformance cutting edges manufactured from speciallyhardened steel are embedded in the drill bit head and professionally ground so that they can be used even in reinforced concrete packed in a see through sturdy plasticwork cassette containing working length 50mm in 5 6 8 10m