The machine is for determining the resistance to wear of small size coarse aggregates and crushed rock. The machine consists of a hollow cylinder, mounted on a sturdy frame on ball bearings. A detachable shelf which extends throughout the inside length of the drum catches the abrasive charge and does not allow it to fall on the cover. The drum is rotated at a sped of 30-33 rpm by an electric motor through a heavy-duty reduction gear. Motor is suitable for operation on 415V, 3 phase, 50 HZ, AC Supply.