<p>In this paper, a numerical model is employed to design a vibrational tool for ultrasonic welding of metal sheets. The system’s resonance frequency and mode shape have been determined. The numerically calculated resonance frequency is 20,285 Hz, compared to the experimentally measured value of 20,538 Hz, resulting in a 1.23% deviation. Similarly, the anti-resonance frequency obtained from the simulation is 20,405 Hz, differing by 1.13% from the experimental value of 20,638 Hz. In the numerical simulation, the maximum vibration amplitude at the horn tip was calculated to be 31.3 µm, representing a deviation of approximately 2% from the experimentally measured value of 32 µm.The CCD experimental design method is used to study the effect of input parameters of welding time and force on the output variable of the weld strength. Test results indicate the presence of maximum strength under specific conditions. Both input variables initially increase the weld strength, but beyond a certain point, further increases lead to a decrease in weld strength. Additionally, the impact of the parameters on weld quality is visually examined using microscopic images. Increasing the input variables similarly increase the penetration depth of the horn’s teeth into workpieces. In the experimental setup, the excitation voltage and power are set to 1500 V and 1300 W, respectively. Optimal mechanical properties for joining two 0.5-mm thick copper sheets are achieved at an applied force of approximately 51 kg and a welding duration of 2.7 s.</p>