This paper studies the influence of process parameters, namely, the load, the load time, and the type of materials, on micro-hardness of the machined surface. The significance of the process parameters and their interactions on the hardness with the help of analysis of variance. Full Factorial Design with two centre point (2 replication) was used for designing the experiments. According to our analyses, the load time and type of material were significant factors. Load, has an insignificant effect.