Cobalt chrome is extremely dense and this is a major factor when sieving it. The material can quickly settle on and in the screen and both coat and blind the screen mesh. The heavy density of it can result in machine overloads and may cause tensioned meshes to begin to stretch and tear.
Standard sieving companies have developed a great method to efficiently sieve cobalt chrome and other similar powders. CHEAT THE HOLE! Use a bigger micron size than actually required. Elcan is not a believer in this methodology. If your powder spec is 44 microns, it should be sieved at 44 microns, NOT 53, 63, or 74 microns as has become common place in the industry.