The central insert works from cutting speed zero to 50% of vc max., and the peripheral insert from 50% vc max. up to vc max. The central insert forms a conical chip, while the peripheral forms a chip similar to that achieved using internal turning with a large depth of cut.
The power required in for the material being drilled is a determining factor
The hole depth is an important factor in drilling as is the radial cutting depth
Chip control are important factors in drilling
Insert geometry and grade selection are key for proper product selection