All spheres are made from pure metals combines to provide required alloy composition according to J-STD-006 specification or customer specific. After forming the spheres are classified for size by a precise and non-abrasive sorting process. The diameters of the spheres are monitored and controlled within 0.001" +/- 0.0005" tolerance. Sphere size distribution is measured precisely by a sophisticated image analysis system connected to scanning Electron Microscope (SEM). To determine sphericity, sphere diameter is  measured in 16 directions in fraction of a second.