The quality of friction stir spot weld is critically influenced by the careful selection of optimal welding parameters, particularly tool rotational speed and dwell time, which significantly affect heat generation and, consequently, the structural integrity of the joint. Using finite element analysis (FEA), the study examines the variations in equivalent plastic strain and induced stress at the conclusion of the welding process and understanding the impact of tool rotational speed on temperature generation and its correlation with energy dissipation in AA6082-T6 aluminum alloy. The FEA results reveal that higher tool rotational speeds 1000 rpm generate maximum temperatures of up to 265 °C, promoting improved metal flow but also resulting in increased plastic strain and stress within the material. In contrast, lower rotational speeds, 400 rpm, yield a maximum temperature of only 140 °C, which is insufficient for optimal metal flow (greater than 160 °C). The 600 rpm speed closely approximates the conditions observed at using high speed, underscoring the importance of selecting the appropriate tool speed for enhancing manufacturing sustainabilitySustainability. The temperature predictions from the FEA were validated against experimental data, demonstrating the reliability of this approach when welding parameters are accurately modeled. This study offers valuable insights for developing strategies to model FSSW processFSSW process, presenting a cost-effective alternative to traditional experimental methods.