These SELFCUT flat bits differ from conventional flat bits as they have a self cutting threaded point to draw them into the work, combine this with the 2 cutting spurs they will cut quickly at a good feed rate. The tip and cutting edges are precision-ground for dimensionally correct bore holes. They all have a 1/4" hexagonal shank as per DIN 3126-E6.3. Suitable for boring holes in hard and soft woods as well as light building materials. The correct drill speed must be selected and this is stated on the packed dependent on the size. A 152mm long extension is available separately.