This document summarizes an experiment that optimized ball burnishing process parameters for hardness of aluminum alloy 6061. A new ball burnishing tool was designed and used to burnish aluminum alloy 6061 test samples. The process parameters investigated were burnishing speed, feed rate, force, and number of passes. Experiments were designed using Taguchi's orthogonal array method. Analysis found the optimal parameters for maximum hardness were 250 RPM speed, 0.06 mm/rev feed rate, 8 Kgf force, and 5 passes. Confirmation tests validated these parameters produced the highest hardness of 126 BHN. Hardness was found to generally increase with speed, force, and passes up to certain levels, then decrease with further increases in those parameters. Hard