High helix/low lead cutting tool

A milling cutter for machining an Integrally Bladed Rotor (IBR) having a rotor disc with a plurality of integral airfoils projecting outwardly from the rotor disc, the milling cutter comprising a shank section joined to a cutting section, the milling cutter being adapted to rotate about a longitudinal axis of the milling cutter during a milling operation, the cutting section including a hard metal body with a plurality of peripheral blades separated by a plurality of flutes, the cutting section having a transverse cross-section smaller than a circumferential space defined between adjacent airfoils, each of the peripheral blades having a leading side, a cutting edge and a trailing face side, each of the cutting edges extending around the cutting section in a helix direction and defining an helix angle between the cutting edge and a line parallel to the longitudinal axis of the milling cutter, the helix angle being determined such that an axial cutting force acting on each of the cutting edges is greater than a force resulting from other cutting forces acting on the same cutting edge and in a plane normal to the axial cutting force.