Pelleted animal feeds are processed from ground and mixed feedstocks. The ingredients are pressed through an array of dies at pressures exceeding 35 MPa. Cubing is a related process, producing larger, more fibrous blocks from chopped materials. The end product is a hardened agglomerated mass that needs to be capable of withstanding subsequent handling operations. The measurement of the durability of the product is very important to the processors and feed handlers. The existing ASAE durability tester (S267) is not adequately sensitive to compare the hardness of pellets and cubes. A new tester, with a working principle based on impact and shear, has been developed and refined for usability. The unit can accommodate pelleted and cubed material varying in size and hardness. The paper discusses the development history of the unit and presents some experimental data from its application.