Abstract: A universal refiner plate assembly and a method of mounting the same within a disk refiner, such as a double disk refiner, a multiple disk refiner, or a counter-rotating disk refiner is described. When refiner plates of different manufacturers are of similar diameters, a universal plate mounting mechanism is possible. One refiner plate will fit in all types of refiners made by various manufacturers. A customized subplate will mount into a disk refiner directly to a rotor or stator as needed. A universal refiner plate will attach to the subplate. As a result, a refiner plate manufacturer will be able to make one refiner plate pattern to be used in various disk refiners of the same diameter. A refiner plate with finer bars and grooves is possible because the size of a refiner plate is reduced. The universal refiner plate and the customized subplate will eliminate the single one-piece fabricated plate currently used in multiple disk refiners.