Abstract: A cutting tool, for example a milling cutter, capable of omini-directional machining of a workpiece as disclosed. In a preferred form, the cutting tool is embodied as a ball nosed end mill having a cylindrical shank terminating in a spherically shaped cutting end with recesses shaped for receipt of at least two indexable cutting inserts, each insert mounted in lay-down fashion, and providing a portion of an effective overall arcuate cutting edge, the cutting zones of each insert overlapping each other. Each insert has the form of an equilateral polygon bounded by planar flanks, each flank intersecting a convex portion of a major face of an insert to form an arcuate cutting edge. The convex major face portion forms the clearance face and the planar flank portion the rake face for each associated arcuate cutting edge.