This paper aims at studying the influence of gangue aiid researching in the theoretical empirical methods in order to limit the formation of such gangue during the manufacture of steel. Gangues are divided to acids, sulfate and compound gangue. Such gangues are known for their bad influence on the mechanical characteristics of steel. Experiments have proved that the influence of Sulfur gangue especially FeS is worse than that of acids, as the melting point is 880t. Such gangue form capillary ducts within steel, thus there will be internal micro cleaves and stress points that will lead to collapse and break when the metal is exposed to stress less than the flowing point which is considered within the allowed stress values.