This paper addresses the transition from the interfacial to the pull-out failure mode for DP780 dual-phase-steel resistance spot
welds under tensile-shear and cross-tension loading conditions. It was studied whether industrial weld-size criteria can produce
pull-out failure modes. Based on the failure mechanism of the spot welds in a cross-tension test, a simple analytical model is
proposed to predict the critical FZ size to ensure the pull-out failure mode. According to the findings, the sheet thickness, the
hardness ratio of the fusion zone to the sub-critical heat-affected zone, the amount of shrinkage voids in the fusion zone and the
width of the HAZ are the main controlling factors for the transition from the interfacial to the pull-out failure mode in
cross-tension loading. The fusion-zone size was proved to be the key factor controlling the cross-tension and tensile-shear
strengths of DP780 resistance spot welds.