Ideal Brush Seater, 3/4 x 1/2 x 4-3/4 in. Soft Grade

For brush seating, choose a stone with a width equal to, or slightly greater, than the width of the brush. For cleaning commutators, pick a stone about 3/4 the length of the commutator bar and as thick aswill neatly fit between the brush riggings. For slip rings, select a stone about 1/2 in. wider than the ring.