Stir cast alloys are beneficial in the aerospace industry by virtue of their low porosity, high specific strength, corrosion resistance, and weldability. Friction stir welding (FSW) is an advanced technique for joining materials in a continuous operation. The present investigation enfolds solid state joining of cast A356 and AA 2014 alloys by varying process parameters such as tool pin shape (cylinder, threaded cylinder, square, and conical), tool rotation speed (1800–2100 rpm), and welding speed (10–25 mm/min). Experiments were conducted to evaluate the influence of process parameters on the tensile and hardness behaviour of the welded specimens. Mechanical test results were assessed and compared with fuzzy logic approach. The results revealed complete fusion in the cast welds with no porosities or segregations, and finer grains resulting from recrystallization. The threaded cylinder and square-shaped tools achieved the highest tensile strength and micro hardness of 136.6 MPa and 109.4 Hv respectively.