| 摘要 |
A rotary spade drill arrangement (1) comprising a combination spade drill body having a rotational axis, a shank portion (3), and a generally planar spade cutter portion (5) with a pair of oppositely directed cutting edges (7) extending radially of the axis, and a rotatable frusto conical cutter (9) mounted on the spade cutter portion (5) adjacent the maximum radial extent of each cutting edge. |
