Friction stir processing is a modified form of friction stir welding process which is introduced to prepare the surface composites or to repair the defects in the surface to enhance the mechanical properties. The process is a green and environmental friendly process, where the required heat is produced by frictional action. In the present work, Surface composites were prepared using Al 5052 as base material and Al2O3 as reinforcement particles. Parameters such as number of passes, spindle speed, feed rate and tool pin profile were taken in three different levels. Six tools were made, three tools with 3:1 and remaining three with 4:1 D to d ratio. Totally 18 experiments were conducted with two group of tools. The results were analyzed to study the influence of above mentioned parameters on mechanical properties like tensile strength, hardness. The results were compared for different D/d ratios. The experimental results revealed that 3:1 D/d ratio tools were given better results than 4:1.Tool with square pin profile given better hardness and strength than the other profiles. This is because of the pulsating effect of the square pin profile. The other parameters have directly proportional relationship up to certain level, after which further increase of parameters reduces the tensile strength and hardness.