- Another important consideration when selecting metal-to-oil seals is their compatibility with the oil being used. Different oils have different properties, such as viscosity and chemical composition, which can affect the performance of the seal. It is essential to choose a seal that is specifically designed to work with the intended oil to ensure optimal performance and longevity.
In this article, we’ve discussed everything you need to know about oil seals, which are sometimes called radial shaft seals. Also, we’ve discussed the various types, their installation, and how to choose the right one for your application. With all these, you will be able to make an informed decision about the best oil seal for your needs.
OS/MOS: Designates if dimensions are displayed in inches or millimeters
Standard springs are made of carbon steel. We use stainless-steel springs for our GR and GRST oil seals made from FKM rubber. In some rare cases, an O-ring is even used as a spring element. Standard PTFE lip seals are not fitted with springs.

Seals are designed to create a tight seal around the shaft by utilising a combination of lip geometry, surface tension, and lubrication. When the shaft rotates, the lip of the oil seal comes into contact with the shaft surface, creating a frictional force that generates heat. This heat helps to soften and conform the elastomeric material of the oil seal to the shape of the shaft, ensuring an effective sealing action.
As type A with dust lip
All are fitted with a spring to preload the sealing lip. All these types are for non-pressurised or low-pressure applications up to 0.5 bar for diameters of a limited size. For diameter of 500 mm or more, the maximum pressure is 0.1 bar. For higher pressures, special types or PTFE lip seals can be used.
Before installing the oil seal, it is important to lubricate it to reduce friction and prevent damage during installation. A silicone-based lubricant is recommended for most applications. If the oil seal is to be installed in a high-temperature or high-pressure environment, a more specialized lubricant may be required.
: prevents particles from reaching the sealing lip.