Abstract
In this paper, the flank wear and the surface roughness of machined surface are investigated by high speed milling of hardened steel for a small size ball end mill using a high speed spindle attachment. And also it is investigated that the influence of a tool life on the inclination angle of work piece and the minimum quality lubrication (MQL) method. By the results, it is shown that the long tool life and the small surface roughness are obtained by the conditions of step up milling, down milling and the MQL method to end point of cutting. But bidirectional milling is most efficient method than other type of milling.
