Brittle and hard materials are problematic to mechanically micro machine due to damage resulting from material removal by brittle fracture, cutting force-induced tool deflection or breakage and tool wear. As a result, the forces arising from the cutting process are important parameter for material removal. This study was undertaken to investigate the effect of cutting conditions on cutting forces and the machined surface during the glass micro grinding using on-machine fabricated (Poly Crystalline Diamond) PCD tool. Experimental results showed that an increase in depth of cut and feed rate can result in increase of cutting forces and surface roughness as well. Among the forces in 3 axes, force along feed direction is found to be larger, which played a major role in material removal. Finally, it is observed that PCD tool exhibits promising behaviour to machine brittle material like BK-7 glass for producing micro molds and micro fluidic devices, since it has better wear resistance, experiences less cutting forces and generates smooth surfaces with Ra value of as low as 12.79 nm.