Abstract: Apparatus is disclosed for producing high purity metal powders of precisely controlled particle size. The apparatus employs a system for atomizing a stream of molten metal by a swirling fluid. After initial system set up, different particle sizes may be produced merely by interchanging atomization fluid inserts. Each replaceable atomization fluid insert includes an inlet for receiving a single gas supply at a fixed pressure. A spiral channel in the insert of decreasing cross-sectional dimension extends from the inlet to an outlet surrounding the streams of molten metal. The channel configuration of each of the replaceable inserts is designed so that a preselected atomization fluid velocity and/or spiral rate is provided for atomizing the molten metal to the desired particle size. Gas jets in a depending cooling tank are used to rapidly cool the particles while keeping them from impinging against the wall of the tank.