Single row inch size tapered roller bearings are the basic and the most widely used type of tapered roller bearings. It consists of the inner-ring assembly and the outer ring. It is usually fitted as one of an opposing pair. During equipment assembly, single-row bearings can be “set” to the required clearance (endplay) or preload condition to optimize performance.Single row inch size tapered roller bearings is widely used in automotive,rolling mill,mining, metallurgy,plastics machinery and other industries. If you want to know more about WSBC 399A/3920 , welcome you contact us freely .