Hollow drill for producing break-through, has fitted cutting segments, where circumference is occupied between certain percentage and quantity of cutting segments is determined

摘要

The hollow drill (1) has fitted cutting segments (2), where circumference is occupied between 40 and 80 percent, particularly between 50 and 70 percent. The quantity of cutting segments is determined, where diameters of the hollow drill are measured in millimeter. The cutting segments are sintered diamond segments.