Abstract
The changes in mechanical and metallurgical behavior of spot welded region generally occur throughout the spot welding process and these changes are very significant for the safety and quality of the welded joints. Due to the influence of current flow, the squeezing time and the load applied on electrodes have a vital effect on the mechanical properties. This paper presents the effect of such parameters on the tensile shear strength of single lap spot welded 6061-T6 aluminium alloy. Two level four factor fractional factorial design was employed to develop mathematical models. It was found that change in weld thickness and current are the primary parameters that control the tensile shear behavior of the spot welds.