Sustainable manufacturing technology is one of the requirements of the current industrial fields to reduce the weight and energy used. Friction stir welding (FSW) can be considered a quantum leap in the development of welding technology. A solid-state process utilizes a non-consumable tool and less electrical energy. Friction stir spot welding (FSSW) is a particular case of FSW that began to spread rapidly, especially for similar and dissimilar metals, which has extended to weld the polymers. The increase of FSSW use in different fields needs to simplify the equipment. This study used a portable drilling machine to construct an FSSW apparatus with a rotational speed between 1500 and 3000 rpm with a pin diameter of 2, 3 and 4 mm. The results indicated that the joints welded by the developed apparatus have good strength and hardness. Furthermore, many specimens succeeded in the bending test, especially when the rotational speed was set at 2250 rpm and the pin diameter was 3 mm. In addition, it was found that the mechanical properties increased with the rotational speed and pin diameter, then gradually decreased. Finally, the Response Surface Methodology (RSM), besides the analysis of variation (ANOVA), was utilized to maximize the lap-shear fracture load. The results indicated that the maximum lap-shear fracture load can be achieved at a tool speed N of {2300>N>1600} rpm with a pin diameter (d) of {2.75>N>3.75 mm}.