sliding bearing knuckle bushing, centripetal knuckle bushing, spherical hinge#500SP5 is based on high strength brass alloy which is processed through unique high-tech cast technique. The anti-abrasion surfaces of the bearing are drilled proportionally and embedded with solid lubricants. Due to its high mechanical strength and hardness, its broadly used for heavy load, low velocity application. There are two kinds of solid lubricants available for different application, such as, SL-1 for general-purpose use, SL-4 for in-water or seawater use. lSelf-lubricated and maintenance-free. lSuitable for heavy load, low speed application. lExert excellent wear resistance where its difficult of lubricating film to be formed during reciprocating, oscillating or frequently intermittent operation. lChemical attack resistant and corrosion resistant.