| 摘要 |
The invention relates to a multiple edge drill such as is especially used for machining difficult-to-machine, e.g. high-toughness materials, such as e.g. cast steel, steel for hardening and tempering or other difficult-to-machine steel materials including metallic cast materials, such as e.g. gray cast iron, and especially GGV or ADI cast iron. The facet is designed in such a manner that the main cutting edge has at least two main cutting edge sections that define point angles of different size, the radially outer point angle being smaller than the radially inner one, thereby obtaining a good cutting behavior and long service life of the tool. |
