| 摘要 |
The present invention relates to a drill bit and a single pass drilling apparatus. The one-piece drill bit has a connection portion, adapted to be rigidly connected to a drill steel, a pilot part and a reamer part. The pilot part has first rock machining means. The reamer part has a first center line and second rock machining means. The second rock machining means is provided axially between said connection portion and said first rock machining means and to one side of the pilot part. The drill bit has a rotational direction. A side of the pilot part facing away from the reamer part is provided with a wear resistant means. The wear resistant means is integral with the first rock machining means. |
