| 摘要 |
PURPOSE:To effectively utilize a cutting blade tip and prevent the nose part of an internal periphery side tip from being broken off by preventing the rubbing cutting of a linear part forming the bottom blade of an outer periphery side tip. CONSTITUTION:For an inner periphery side tip 18 and an outer periphery side tip 19, rhomb-shaped tips or parallelogram-shaped tips being in the same shape and size with each other are used, and the obtuse nose part of the inner periphery side tip 18 is located on the central part of the tip of an end mill body. On the other hand, the acute nose part of the outer periphery side tip 19 is located ahead of all other cutting blade parts, while this tip edge and rear end edge of the linear part extending from the acute nose part to the rear in the axial direction of the end mill body are placed at approximately equal distance from the axis of the end mill body. |
