Attrition of particles is unavoidable in many processing operations. One of the methods available for the evaluation of the phenomenon relies upon the testing of materials in an annular shear cell in which a sample is subjected to known stress and strain. In previous work the extent of attrition has been related by a power law relationship to the shear strain. Here the approach is evaluated over a far wider range of parameters than has been attempted hitherto, normal stresses now ranging from 0.15 to 292 kPa, and shear strains from 0.9 to 8 x 10(4). This was performed on two types of ceramic cylinder, similar to some catalyst supports, which were manufactured under well-controlled conditions. Despite a changing balance of the processes of fragmentation and surface abrasion due to the effect of stress, the data for each material was unified whatever size cut was selected to represent material that had suffered attrition. Experiments with a range on initial particle shapes formed by the method showed the same behaviour except when the extent of attrition was assessed at the largest sieve cut size. The method is effective in describing the complexities of attrition as the pattern of breakage in an environment in which force transmission changes in the stress chains as these vary with the changing size distribution. (C) 2003 Elsevier Ltd. All rights reserved.