| 摘要 |
A rotary cutting tool includes a body having a cutting portion and an axis of rotation therethrough. The body has a plurality of helical flutes formed in a circumferential surface of the cutting portion in circumferentially spaced relation to one another and extending helically axially of the cutting portion so as to define a plurality of helical lands of a generally uniform land width spaced circumferentially of the cutting portion from one another. The body has a plurality of helical peripheral cutting edges each defined by a portion of an inner surface of a respective one of the helical flutes facing in a direction of rotation of the body and a surface of the land adjacent to the portion of the inner surface. At least one of the peripheral cutting edges has a helix angle different from helix angles of the other peripheral cutting edges. The peripheral cutting edges are equally spaced circumferentially of the body in at least one plane disposed perpendicularly to the axis of rotation of the body. |
