The mechanical strength of porous alumina catalyst carrier beads, used in the reforming units with continuous catalytic regeneration, was measured by impact testing. With this testing method particle strength can be measured at higher strain rates than the traditional crushing test method, hence providing a better simulation of pneumatic conveying and chute flow conditions, and also a large number of particles can be tested quickly. This is important for particles with a brittle failure mode such as the alumina particles used in this work as a wide distribution of mechanical strength usually prevails. Extensive impact testing was carried out first with an industrial sample, in order to understand the failure mechanism of this type of particles and to develop a methodology for analysing the extent of breakage by impact. Then the method was used to analyse the effect of a number of process parameters, such as filler, macroporosity and drying procedure on the particle strength with the aim of optimising the manufacturing process. The impact test results were then used to test the model of breakage behaviour of particulate solids proposed by Vogel and Peukert [Vogel and Peukert, Breakage behaviour of different materials-construction of a mastercurve for the breakage probability. Powder Technol., 129 (2003) pp. 101-110]. (c) 2005 Elsevier B.V. All rights reserved.