Abstract: This work discusses the effect of main controlling parameters of spot welding process on the quality of dissimilar welded joint between ferritic stainless steel grade 430, FSS with 0.5 mm thickness and low carbon steel, LCS with 0.6 mm thickness sheets. Parameters studied were welding current, welding time and electrode pressure. Metallurgical and mechanical characteristics were determined through microstructure, tensile shear and microhardness examinations. The results of this study showed that the suitable electrode pressure in this dissimilar combination of steels; FSS and LCS; was 0.2MPa (2 bar). It was found also that the welding current is the most influential parameter on weld quality. The best weld strength was obtained at 3.4 KA. Increasing welding current and welding time up to certain level increases the joint strength, after this level the joint strength decreases. Investigations showed also that the dominant structure of the nugget is martensite. The fracture due to tensile shear test was mainly intergranular in ferritic stainless steel side and the fracture mode was button pullout
