According to a model which yields crack resistance values in good agreement with the experiments of Sigl and Fischmeister, crack propagation in WC-Co is opposed by the plastic stretching of binder ligaments and by the fracture energy of the carbides surrounding them. The size of the plastic zone is less than the mean free path in the binder, but very large strains occur in the ligaments. In contrast with this, a finite element model (FEM) study by Ljungberg et al. indicated a very large plastic zone. The present work shows that FEM calculations with a sufficiently fine net will model the localized deformation of the binder at the edges of the carbide cracks in good agreement with our experimental observations, confirming the proposed mechanism of ligament formation and crack propagation.