The measurement of melt quality of aluminum alloys have been a complex phenomenon. There exists various methods but the general experience show that they were slow, complicated or expensive for use on the foundry floor. In addition, these methods were not quantifiable. For the first time, bifilm index was proposed by the authors which give a numerical indication of the melt quality in millimeters as the total oxide length. Numerous studies were carried out to correlate this index with the mechanical properties. In this work, toughness measurements were made by using MatLab software. Alloy studied was 356 which were cast under various conditions (degassed and upgassed for 0.1, 0.2 and 0.4 cm(3)/100g Al) and the results were correlated with bifilm index.