Abstract
The paper discusses micro cutting of ultra fine grain steel with measuring the cutting force, the shear angle and the shear stress on shear plane. The cutting tests were conducted in a planing manner on the developed machine tool. The dynamic component in the cutting force of the ultra fine grain steel is less than that of the normal grain steel. The shear angles were measured with changing the cutting depth. The shear angle increases with the cutting depth. The shear angle of the ultra fine grain steel is larger than that of the normal grain steel. Although the effect of the grain size on the shear stress on the shear plane is not large, larger scattering is observed in the shear stress of the normal grain steel for the cutting depth.
