The term agglomerate is generally described as an assembly formed by various binding mechanism 1)2)3) existing between solid particles. A number of problems relating to agglomerate strength are divided into two groups. One is the breakage of spherical or irregular shaped agglomerates induced in particle handling processes such as solid-liquid mixing, moving bed, fluidized bed, rotary drum, hopper, and so on. Another is the evaluation of a strength of agglomerates or compacts handled in the field of various granulation techniques. In view of each agglomerate having various shapes, dimensions, and particular structure, it is extremely difficult to indiscriminately discuss the mechanical properties related to agglomerate strength. However, it is well known that typical tensile strength of agglomerate, in general, is influenced by particle diameter and porosity as shown in Fig. 1, and also the pioneered studies on other important factors influenced by forces existing between particles have been made by Rumpf and his coworkers 4)5). Other agglomerate strength, generally, of abrasion/attrition and impaction are important factors 6)7) to judge whether or not their shapes are maintained during handling and processing in various industries.