Fig. 1 shows the ultrasonic vibration cutting system used in these experiments. The system is attached vertically to the cross slide of a two-axis CNC ultra-precision diamond turning machine (Precitech 2800). This machine is equippedwith a precision air-bearing spindle of a high radial and axial stiffness and two slides which are supported by hydrostatic oil bearings. The position feedback resolution of the machine is 8.6 nm.