Longer seal life can be expected with shafts having a Rockwell (RC) hardness of 30 or more. When exposed to abrasive contamination, the hardness should be increased to RC 60.
What are Oil Seals and how should they be ordered?
Double metal cased
Oil Seals 101 – Part 1

Oil seals operate by creating a tight barrier between two moving or stationary parts, such as a shaft and housing, to prevent oil from escaping and contaminants from entering the system. This is essential for maintaining the efficiency and performance of the machinery, as well as preventing potential safety hazards.
The advantages are low friction and minimum power consumption, the possible use even in case of insufficient lubrication, operating range of -130º c to +200º c and much more: high chemical resistance and a low breakaway torque after standstill. Further, the PTFE, when heated, can” remember” its original form and return to it (phenomenon known as” plastic memory effect”).Therefore, this kind of seal do not need the old school metallic spring.
Sometimes, two different kinds of fluids leak from one chamber to another and gets mixed up. Here, this type comes as a boon. This is a metal inserted duplex type oil seal recommended on such assembly where mix-up of two different fluids is to be prevented.
Figure 7: Oil seals for steel production equipment (rolling mill)
Valve Cover Gasket: Role in Engine Functionality
Rubber valve cover gaskets are crucial components in automotive engines, serving to create a secure seal between the valve cover and the cylinder head. These gaskets prevent oil leaks and contaminants from entering the engine, ensuring proper lubrication and protection of critical components. High-quality rubber valve cover gaskets are essential for maintaining the integrity and performance of the engine, contributing to optimal engine operation and reliability.
An oil seal type that is resistant to oils, fuels, and solvents, fluorosilicone also offers temperature stability. Primarily found in aerospace fuel applications and automotive fuel emission control, this o ring material is fast becoming popular in more and more oil-based applications across a wide spectrum of industries.
The perfect remedy for this is to use oil seal materials that are rated for the temperature of your application. Also, ensure that the elastomer is free from volatile constituents like waxes, plasticizers, etc.
Case study 3: Product changes in oil seals
Select the correct oil seal size
It is quite common for a groove to develop at the sealing lip at some point due to long-term use. As a result, the new oil seal no longer fits and seals properly. It is not strictly necessary to replace or repair the entire shaft. Take a closer look at the dimensions first. It may be possible to fit with a slightly narrower or wider oil seal next to the groove. Alternatively, using the Speedi-Sleeve repair kit, repair the running surface under the seal.