Friction stir welding (FSW) is a method of solid state joining in which the joint is produced below the base metal's melting temperature.This research work investigates the welding properties of the aluminium alloys using the friction stir welding technique. A novel Taguchi-grey relational analysis (GRA)-principal component analysis (PCA) approach were used, the effect of process parameters such as tool feed rate, tool rotational speed, and tool pin profile were discussed to find the best fair weld quality. According to the Taguchi L27 orthogonal array, twenty-seven experiments were designed and the quality of the experimental sample were tested for shear tensile strength, yield strength (YS), percentage elongation (PE), and weld zone hardness (HZ). The optimum process parameters of Taguchi-GRA-PCA results showed with the traverse speed of 70 mm/min, a rotational speed of 1400 rpm, and a triangular tool pin profile. Analysis of variance (ANOVA) evidenced that all the three parameters were significant with the P and F value, and rotational speed was the predominant parameter with 43.56% contribution. Thus, the optimal conditions for this research showed 1.28 percent improvement in the overall weld quality.