Abstract: Apparatus for determining the mechanical properties of particulate material comprises an outer member defining a cylindrical cavity, and an inner member rotatable in the cavity, the inner and outer members together defining a pulverizing chamber. The inner member has a pressure-bearing face facing the pulverizing chamber and a diametrically disposed groove in which a steel blade can be fitted so as to protrude into the pulverizing chamber. In use, the inner and outer members are rotated with respect to one another, while the particulate material in the pulverizing chamber is placed under axial compression. The torque transmitted from one member to the other, as well as the axial force transmitted from one member to the other is measured during the relative rotation, and these measurements used to determine the mechanical properties of the coal as well as the wear characteristics of the blade.