
The quest for the continued improvement of weld quality cannot be over emphasized. Hence, every good manufacturer is eager to find better ways to improve product quality. Research has shown that one of the practical ways to improve on weld quality is to optimize input process parameters. The aim of this study is to optimize and predict the Weld Penetration Size Factor (WPSF)of TIG mild steel welds using Response Surface Methodology (RSM), with the purpose of achieving optimum results. In this study, several sets of experiments were carried out. The input parameters considered were the applied current, voltage, and gas flow rate. The TIG welding process was used to join two pieces of mild steel plates, after which the WPSF was measured respectively. The experimental result was analyzed using the RSM. The results obtained showed that current of 140.01 Amp, voltage of 20.00 volt, welding speed of 150.00mm/min, and gas flow rate of 12.01 L/min will produce a weld with the following optimum properties of WPSF at 2.6636mm. This solution was selected at a desirability value of 97.30%