Tapered roller bearings are designed so the tapered vertex of the raceway surface of the inner and outer rings and roller converge at one point on the centerline of the bearing. Due to this design feature, rollers move along the center of the raceway surface. 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 variety of these bearings, including single, double, and four row arrangements, are in use both in metric and inch series