NBR, FKM or HNBR? Choosing an oil seal compound

The rubber compound sets the temperature a seal can live with, and it has to suit the oil or grease it touches. Start with the operating temperature, then check the medium and the shaft speed.

Reference temperature ranges

• NBR (nitrile): −40 to 120 °C
• HNBR: −40 to 150 °C
• ACM (acrylate): −25 to 150 °C
• FKM (fluoroelastomer): −20 to 200 °C
• VMQ (silicone): −70 to 220 °C
• PTFE: −100 to 280 °C

For water, steam, sea water, acids and alkalis, the spring and the metal case can be 304 or 316 stainless steel instead of carbon steel. Properties vary with compound, so send us your operating conditions for a recommendation.

Materials and temperature chart