| 摘要 |
Abstract The present invention provides a drill bit comprising a shaft having a drilling end defining a drill point; at least one face that extends to at least partially define the drill point, the or each face generally subtending an acute angle with a longitudinal axis of the shaft; and at least one flute defined in the shaft for directing away debris produced during drilling. Fig. 1 1 109a 105 109b 107b 115 111a r1T |
