Tapered roller bearings are designed so the tapered vertex of the raceway surfaces of the inner and outer rings and rollers converge at one point on the centerline of the bearing. Due to this design feature, rollers move along the center of the raceway surfaces. The tapered rollers are guided by the compound force of the inner and outer raceway surfaces which keep them pressed up against the large rib on the inner ring. A large veriety of these bearings, including single, double, and four row arrangements, are in use both in metric and inch series.