An Extra high speed of 30000 - 60000min-1 has been achieved on this attachment, on which the spindle is supported by aero-static bearings. The tool also contains a unique head design that allows the machining of deep and narrow areas on dies and molds where small end mills are required. Spindle runout on the head is less than 0.07μm. Therefore results attained have been excellent on die and mold surfaces, and in certain cases has eliminated the need for electrical discharge machining and difficult-to-cut extra hard materials.