Due to the high strength to the weight ratio and the ability to form the desired shape, AA2017 is extensively used in the automobile industry. The ability to join with other aluminum alloys and the capability to respond to the heat treatment creates opportunities for the engineers to join AA2017 and AA6061 blanks using friction stir welding. Controlling process parameters is a challenge and optimization of tool pin geometry, axial force, tool rotational speed, welding speed, and tool tilt angle will influence the mechanical and metallurgical properties of the tailor welded joints. Three different tool rotational speeds, welding speeds, and tool tilt angles were used to fabricate tailor welded blanks joints. The ultimate tensile strength and tensile elongation of tailor welded joints were predicted using mathematical regression models, and the models were validated with the experimental results. Tailor welded joints were tested to study the effects of these three parameters on the ultimate tensile strength and tensile elongation. Results obtained gained a clear perspective of process parameters on joints with optimal mechanical properties.