No single physical property of rubbers is responsible for the successful performance of an oil seal or ‘O’ ring. The ultimate tensile strength, breaking elongation, modulus, shore hardness, creep and stress relaxation in tension and compression loads are all important physical properties that characterize a seal or ‘O’ ring. Compression strength and set together with stress relaxation or decay are important for effective sealing. The difference in these properties in a swollen seal is highly critical. An optimum swelling value in a fluid medium is a desirable feature. De-swelling decreases the seal pressure against the wall of the housing where the seal is fixed, leading to leakage. Over swelling minimizes the physical properties of the rubber. Seals made of polysulfide rubbers have extreme fuel resistance but undesirably high compression set. The effect of temperature on the seal is an important factor. Swelling under stress can increase at higher temperatures and a suitable compounding technique should be adopted to reduce this effect.
Significance of Valve Cover Gaskets and Head Gaskets


The pulley is kept from turning on the crankshaft by a key fitting into grooves on the crankshaft and pulley.
Rubber valve cover gaskets offer several advantages, including flexibility, resilience, and resistance to heat and oil. These gaskets are designed to withstand the demanding conditions of automotive operation, providing reliable sealing solutions that contribute to the overall performance and safety of the vehicle. The use of high-quality rubber valve cover gaskets ensures effective sealing and protection of the engine components, contributing to the longevity and efficiency of the engine.
How do oil seals work?
6, the seal is cheap.
Polytetrafluoroethylene
Chemical resistant
Low coefficient of friction poor elastic properties not wear resistant if used by dynamic applications
Nitrile is the most widely used rubber (elastomer) and it’s recommended as the best for almost all standard applications. This is solely due to the fact that nitrile has some intrinsic properties, such as low cost and compatibility with most environments. Some of the general applications of nitrile are non-latex gloves, automotive transmission belts, footwear, gaskets, synthetic leather, hoses, o-rings, and oil seals.
For more information on the characteristics of Oil Seals click on some of the links below:
Figure 3: Sealing function of main lip radial load
* KOYO is a registered trademark of JTEKT.
Neoprene foam gaskets are an essential component in various industrial and commercial applications. These gaskets are made from a type of synthetic rubber known as neoprene, which is valued for its excellent resistance to chemicals, oils, and extreme temperatures. Neoprene foam gaskets have unique properties that make them ideal for sealing and insulation purposes in a wide range of industries.