Presently, there are many different available material models. Some are used for modeling loose materials such as soil and sand. Such models could be usable for modeling the behavior of fragmented biomaterials e.g. sawdust. The subject of the present article is the M-C model, one of the models for describing the characteristics of plasticity in a material. The article presents the method of determining the material constants used in this model, including the cohesion coefficient and angle of internal friction. The results and types of experimental examinations necessary for the purpose of the implemented task are also presented herein. The study was carried out for the oak and pine sawdust mix.