. Stone mounted on a straight handle for difficult to reach commutator Commstones should be twice as long as the width of the longest flat spot and as long as will work freely between adjacent brush sets.
Mildly abrasive, they do only enough cutting to produce a high polish and fine finish. Rubrite, 1/8 in X 1 in X 5 in, Unmounted. They are slow-wearing, non-loading, and will not gum or dust.