For high load low speed of rotation,oscillating motion and the heavy load can not open and close as often as the site,under the boundary lubrication conditions,long-term use without refueling,refurling process will greatly improve the life of sleeve.Wear-resistant surface layer of the oil hole size holes can be used as storage.Has been widely used in metallurgical machinery,mining machinery,imigation machinery motor vehicles,construction machinery,agricultural machinery,steel rolling machinery.