What Is an Oil Seal?
An oil seal (radial lip seal) is a precision elastomer component that seals the gap between a rotating shaft and a stationary housing bore. It consists of a metal casing (for rigid mounting), an elastomer lip (spring-loaded against the shaft), and a garter spring that maintains lip contact as the seal wears.
Materials
NBR (Nitrile): Standard, mineral oils, -40C to 100C. FKM (Viton): Synthetic oils, chemicals, -25C to 200C. PTFE: Universal chemical resistance, -70C to 250C. EPDM: Water, steam, brake fluid, -50C to 150C. See the Seal Selection Guide and our Sealing Solutions catalogue.
Frequently Asked Questions
What is the difference between an oil seal and a bearing seal?
A bearing seal is an integral part of the bearing itself (e.g., 2RS rubber seals, ZZ metal shields). An oil seal is a separate component installed in the housing bore to seal around the shaft, providing an additional external barrier against contamination and lubricant loss.
What material should I choose for an oil seal?
NBR (nitrile) for general mineral oils up to 100C. FKM (Viton) for synthetic oils, high temperatures up to 200C, and chemicals. PTFE for extreme temperatures (-70C to 250C) and aggressive chemicals. EPDM for water and steam applications.