摘要 |
An indexable insert drill employing a pair of radially opposed inserts having either positive or negative axial lead cutting edges extending in the same cone of revolution. One of the inserts has a radially inner arcuate corner intersecting and extending across the axial center line. The other insert is located relatively overlapping but outward radially with an outermost corner adapted to finish cut the side wall diameter of the hole. Insert cutting edges provide for chip interruption and breakage. |