The applications of hard and brittle materials, such as hardened steel and ceramics, have been increasing more and more. It is necessary to find a machining technique with high efficiency, acctuacy and economy for this kind of materials. In present work, an investigation on the machinability of these materials by applying ultrasonic vibration technique with a carbide tool is developed. For that purpose, experiments of cutting mechanism are made and some significant suggestions concerning the utilization o...