A test was performed to further define the mechanical properties of rounded ceramic particles. This test involves the measurement of the strength of individual particles under a compressive load using a standard compressiontesting apparatus. An average of several crush strength determinations is used to assign a compressive strength value to each material tested. The materials used were glass beads, SiO/sub 2/ particles, ZrO/sub 2/ spheres, and Al/sub 2/O/sub 3/ spheres. The test was designed to investigate various test parameters that affect crush strength values. It was found that considerable variation resulted from the use of anvil materials which differed in hardness, i.e., tungsten carbide, sapphire, and hardened steel. The crush strength of particles of a single material was found to vary with shape and size. Particles with spherical shapes produce higher crush strength values than those with rounded or egg shapes. The spherical particles crush under a nearly perfect axiai compressive load whereas rounded particles are exposed to a shear component. Larger diameter particles of a given material crush under higher loads than smaller particles of the same material. It is believed that this is due to the lower load per unit area on the larger particles. Typical results formore » each material are presented graphically including crush strength charts, comparison of shape factors, and particle diameters. (auth)« less