In this study, an instrument for air classification of metal powders was desinged and constructed. Powders were fed through a chute to a rotating disc which sprayed them horizontally. Powders were deflected from their horizontal path by gravity and air flow. Disc speed and air pressure were adjusted so that coarse powders pass a barrier while fine powder fail to do so. The tests with dry casting sand were successful in classification. But, there were problems relating to powder feeding and air pressure.