Quantitative analysis of characteristics in powders and powder processing is essential for the quality control of the products or the processes. The present effort has been focused onto relationship between the fluidity and the particle characteristics of metallic powders. The flow ability [cm³/sec] and the repose angle [deg] have been measured as quantitative values of the fluidity. The fluidity has been discussed with the parameters which characterize the particle properties. The results are summarized as follows:
1. The relation between the flow ability and the repose angle can be expressed quantitatively with an exponential equation.
2. The fluidity is mainly controlled by the product of two parameters concerned with the mean particle size and the mean particle shape of powders and it can be predicted from the particle characteristics.