| 摘要 |
<p>A drill bit, has a front side (5) and a circumferential surface (19) adjoining the front side (5). The front side (5) has a main cutting edge (7) including a transverse cutting edge (3) extending through a center axis (11) of the drill bit (1), and has two first and second main cutting-edge regions (13, 15) adjoining the transverse cutting edge (9) and extending radially toward the circumferential surface (19). The circumferential surface (19) comprises at least two chip flutes (21, 23), which between them delimit a first and a second web (25, 27), and three lands, of which a first land adjoins the end of the first main cutting-edge region (13) facing away from the transverse cutting edge (9), and serves as a free cutting-edge land (33), and additionally has a free cutting edge (39), a second land adjoins the end of the second main cutting-edge region (15) facing away from the transverse cutting edge (9), and serves as a guide land (35), and a third land serves as a support land (37). The drill bit is characterized in that the guide land (35) is disposed on the first web (25) and the support land (37) is disposed, together with the free cutting-edge land (33) having the free cutting edge (39), on the second web (27).</p> |
