Used to determine the resistance of aggregates to abrasion. It comprises a heavy steel cylinder of 711 mm inside diameter x 508 mm inside length, mounted on a base frame. The cylinder rotates at a speed of between 31 and 33 rpm. The machine is fitted with an automatic digital counter which can be preset to the required number of revolutions of the drum. The cylinder is counterbalanced so that the filling opening stays in position without tilting; a push-button allows to position of such opening for the loading/unloading operations. Supplied without abrasive charges to be ordered separately according to the requested Standards. It cannot be sold in the CE markets without protection (see accessories).