| 摘要 |
<p>The front cutting edge (10) is provided with an inner front cutting edge (17) connected with an inner lateral cutting edge (11) and an outer front cutting edge (18) connected with an outer lateral cutting edge (12). A front flank (13) corresponding to the front cutting edge (10) is provided with an inner front flank (19) corresponding to the inner front cutting edge (17) and an outer front flank (20) corresponding to the outer front cutting edge (18). An inner front clearance angle (²19) of the inner front flank (19) is set at a larger value than an outer front clearance angle (²20) of the outer front flank (20). Therefore, it is difficult for the hole cutter to be chipped, and its cutting performance is also good (Fig 3).</p> |
