The present study investigates the effect of joining parameters on the mechanical characteristics of dissimilar friction stir spot welding (FSSW) between AA 6061 Al and galvanized steel. Mechanical performance has been evaluated by shear and microhardnes testing. A macrostructural examination has revealed the creation of mechanical interlocking in the Al steel connections. Shear failure load has increased with increasing both tool rotational speed and plunge depth for all FSSW connections. Higher plunge depth has improved the mechanical interlocking between lower and upper sheet due to the formation of a larger secondary flash
