A rubber rotary shaft oil seal generally consists of an outer circular metal part and an inner flexible member that does the actual sealing and is bonded to the metal part by chemical adhesive agents. The sealing member is made of rubber, either synthetic or natural as the case may be and is widely used to prevent the leakage of oils or grease along a rotating shaft. Oil Seals AKA Hub Seals are offered in many different styles i.e. Single lipped, double-lipped, fully metal cased, springless and more. Choose a material below and search for the correct size.