| 摘要 |
<p>The invention relates to a boring bit (1) capable of right hand and left hand rotation for use in rapid boring operations. The cylindrical boring section (3) of the bit has a pair of spaced rectilinear grooved cutting channels (5, 7) which form a dual pair of cutting edges (5, 5', 8) which in a preferred form are of unequal length with respect to the tip (4) of the bit. With this design cutting occurs strongly in both rotational directions with an accompanying balanced cutting load which reduces the likelihood of producing an oversize hole in a work piece.</p> |
