PTFE, which is used in the well-known brand Teflon®, is less commonly used, but it is the preferred material for specific rotating seals in the chemical, food and pharmaceutical industries. This material is notable for having a very low frictional resistance and the best chemical resistance. It can also withstand a very wide range of temperatures in these types of seals; -80 ˚C to 200 ˚C. The shafts on which oil seals with PTFE lips are used require a harder and finer finish. Something like an axle sleeve can also be used to meet this requirement.
Here are some additional tips that will help you have a successful O-ring installation.
These are comparable to type R and RST, except the outer case does not have a metal reinforcement ring. To compensate, the outside is not made of normal rubber, but a hard, heavy-duty rubber fabric. The advantage is that these types can be made in a split version. They are almost always produced to order, and made of NBR or FKM.
Perfect Seal - of fluoro rubber
b + 0.8 Valve Cover Gasket and Spark Plugs: Ensuring Proper Sealing and Ignition
Oil seal size
Cassette seals are designed to maximise grease or oil retention and protection against liquid or solid contaminants. These seals are provided with their own bushings in which dirt is kept out and oil/grease kept in by a multi-lip seal.
Purpose of an Oil Seal



u shaped rubber gasket. The U shape of the gasket creates a compression seal when it is installed, ensuring that no air or liquid can escape from the sealed area. This tight seal helps to prevent leaks, reduce energy loss, and protect sensitive equipment from environmental contaminants.
Figure 2.9. Metal to rubber bonded seal