Rubrite flexible abrasive cleaning stones are excellent for removing surface imperfections from any metal. Mildly abrasive, they do only enough cutting to produce a high polish and fine finish. They can also be recommended to provide a smooth, clean finish on machined parts. - They are slow-wearing, non-loading and will not gum or dust. Recommended in commutator maintenance for periodic cleanup of surface or for polishing the commutator after grinding with Diamond D commstones.