9313162 Tlusty The research is for investigation of the mechanics of high- speed, thin-chip milling of hardened steels, taking into consideration the effects of high pressure coolants. The research also involves investigation of the most suitable tool geometry, a theory of chatter and of resonant vibrations for ball-nose thin- chip milling, simulation software for forces and vibrations, improvements in machine tool and spindle design, software for the corresponding strategies of numerical control, and demonstration and economic evaluation of this technology. The research is expected to result in recommendations concerning machining conditions, tools, tool holders, spindles, machine tools, and programming considerations for high speed machining of dies. The productivity rates and surface finish are expected to be better than those achievable by current electro- discharge machining technology, and are expected to benefit the die manufacturing industry.