This listing is for 2 piece/s.Self-lubricating bearings, as the name suggests, provide their own lubrication during operation without requiring application of grease or oil lubricants. Due to this, self-lubricating bearings are also referred to as maintenance-free or greaseless bearings as they require no relubrication or grease. Self-lubricating bearings work by having lubricant impregnated within the sliding layer of the bearing. This lubricant can either be liquid (oil) or solid (graphite, MoS2, lead) based on the requirements of the application (such as operating temperature). As the bearing operates, the lubricant is released through pores in the sliding layer, lubricating the bearing surface. The lubricant is uniformly dispersed throughout the sliding layer and thus there is no reduction in low friction bearing performance, even if the sliding layer becomes worn. A "running-in" surface is also usually included at the top of the sliding layer to provide low friction bearing performance at start up before the impregnated lubricant reaches the bearing surface. Industries Agriculture Cement Fans and Blowers Food and Beverage Material Handling Medical and Health Care Packaging Paper Print Quarrying, Mining and Construction Textile and Leather Utilities Benefits Simple cost effective bearing arrangement - units can be regreased. Can be used on fabricated and general engineering equipment. Secure shaft locking for all speed, load and vibration conditions. Effective sealing for all conditions and applications. Protects from the dangers of rotating shaft ends. Specifications Shaft Diameter (d): 20.00mm Insert Type: EC - Eccentric Collar Flat Back Outside Diameter (D): 47mm Inner Race Width (B): 30.92mm Outer Race Width (C): 14mm