| 摘要 |
<p>PURPOSE: A cutting tool for drilling is provided to perform stable drilling by uniformly forming the width of chips. CONSTITUTION: A cutting tool for drilling comprises a main body(17) and changeable inner and outer cutting inserts(20,22). The main body comprises a chip flute(19). The inner and outer cutting insert are arranged in the insert pocket formed in the end unit of the chip flute. The inner cutting insert is located closer to a center axial line(30) than the outer cutting inserts. The bottom end of the cutting edge of the inner cutting insert is located in the distance of 1/4 of the diameter of the drill, from the central axis line to the radial direction of the main body.</p> |
