Oil seals, also referred to as shaft seals, are widely used to prevent the leakage of medium (such as oils and grease) along a rotating shaft. This leak prevention is primarily achieved by the sealing element which can be made from a wide range of materials that are chosen according to each application. They are commonly used in gearboxes, hydraulic cylinders, and related components.
Metal O.D. wall
(with a reinforcing inner metal case)
How do oil seals work?
Slowly raise the engine about 11 in. (38 mm) and insert wedges between the mounting rubbers and pads .
The main benefits of Nitrile when opting for use as an oil seal includes:
Rubber O.D. wall type Provides stable sealing performance around the seal O.D. surface.
Oil Seals 101 – The Ultimate Guide
Rotary Wheel Of Auto Parts
They are typically made from elastomers such as rubber or silicone and consist of an outer metal case with a sealing lip on the inner side.

A wide range of sealing devices are used in various machines.
Sealing devices serve the following functions: