Tungsten inert gas welding (TIG) is a high quality welding process commonly used to join plates of higher thickness in load bearing components. This process provide a pure and clean high volume weldments. The main purpose of present work is to investigate and correlate the relationship between various parameters and hardness and tensile strength of single square butt joint and predicting weld bead qualities before applying to the actual joining of metal by welding. Changing different welding parameters like effect of Gas flow, voltage and welding current on the tensile strength of the weld joint has been investigated . Hardness value of the welded zone has been measured at the cross section to understand the change in mechanical property of the welded zone. In this study we see which parameter most effectively effect the weld strength. Weld strength varies under various conditions. By using Taguchi and ANNOVA technique an optimal solution is found out, which provides us an optimal results of the varying condition.