The traditional Bond work index proposed by F.C. Bond over 60 years ago is still today a useful tool for characterizing material crushability and grindability in the minerals industry. Although not as popular as the Bond ball mill or the Bond rod mill work indices, the impact work index, also called Bond crushability index, continues to be much used for crusher selection. The present work shows the application of a model that combines measurements of particle fracture energies and a parameter that characterizes material amenability to breakage by repeated impacts in the prediction of the Bond crushability index. Results show that a reasonably good agreement exists between measured and predicted results, as long as losses in the pendulum apparatus, used to determine the Bond crushability index, are taken into account in the simulations. (c) 2007 Elsevier Ltd. All rights reserved.