Borrskär för metallborrning

摘要

A cutting insert for a during includes a broken main cutting edge, the ends of which join respective additional edges of the insert by curved nose portions. Each curved nose portion forms a curved cutting edge defined by at least three sequentially arranged curved cutting edge segments defined by respective radii of different sizes. A first of the segments joins one end of the main cutting edge and has a first radius. The next segment has a radius of different length than the first radius and projects farther laterally than the first segment to perform a wiping function.