Image Number 4 for United States Patent #6893195.
For producing forked roots of turbine blades, the turbine blades are, in a first step, roughed-in and smoothed (finished) on their outer faces in a single operation with two rigidly coupled disk milling cutters that are provided hard metal cutter inserts. In a second step, the forked root is formed with fingers by a set of rigidly coupled disk milling cutters that are provided with hard metal cutter inserts. The disk milling cutters form slots in the forked root. All of the slots are simultaneously opened (roughed-in) and smoothed (finished), the slots having parallel walls.