| 摘要 |
A drilling tool has a shaft with a drill head at one end and including a receiving region for a cutting plate as well as two guiding regions. The receiving region and the guiding regions project radially outwardly beyond the diamete r (D1) of the shaft. An enveloping circle enclosing the guiding regions, has a diameter corresponding at most to the diameter of an enveloping circle enclosing the radially outer edges of the cutting plate. Excellent guidance of the drilling tool in a borehole is effected by the guiding region which extend partially parallel to the drilling direction. |
