Abstract: A ball bearing is balanced by orbiting the balls in the gap between the race defining members, magnetically causing the orbiting balls to assume a spaced symmetrical array about the gap, and then inserting a keeper device in the spaces between pairs of balls, to preserve the array for the finished bearing when the set of balls ceases orbiting in the gap. Earlier, the balls were inserted between the race defining members, in preparation for the balancing operation, by angularly deflecting the relatively outer race defining member from the plane of relative rotation until the balls could be inserted through an end opening of the gap, at one circumferential side thereof.