Gas porosities and Fe-rich phases and entrapped double oxide films (hereafter: oxides) are known to be the most detrimental defects in cast Al–Si–Mg alloys. The effects of H (gas porosities) and Fe ( b-Al5FeSi phase) on reproducibility of tensile properties in Al–7Si–0.35Mg alloy have been investigated in this study. Four different casting conditions (Low H–Low Fe, Low H–High Fe, High H–Low Fe and High H–High Fe) were studied. In each case, 30 tensile test samples were prepared by casting in a metallic mold and machining (total of 120 tensile test samples). Results of tensile test were analyzed by Weibull threeparameter analyses. The microstructures of samples were studied by optical microscope. Total of 800 metallography images (200 images for each experiment) were taken and analyzed by image analysis software. Finally, the relationship between tensile properties and defects characteristics was discussed According to the results, Fe ( b-Al5FeSi phase) showed considerably larger negative impact on tensile properties of the alloy compared to H (pores). Results of Weibull analysis revealed that the scattering of tensile properties was mainly due to the presence of b phase within the microstructure. Results of image analysis showed that the pore area% and number of pores/cm2 were mainly controlled by H and Fe content of the melt, respectively. Also, it was shown that Weibull modules of UTS and El% increased linearly with increasing the shape factor of pores. Furthermore, tensile properties of the examined alloy showed strong dependence to the number of pores
