Typical Bearing Materials and Temperature Limits

Many problems with bearing applications revolve around operating a standard bearing product in heat related applicatons. The typical bearing has been processed in a heat treatment cycle that provides dimensional control only up to 250F or 300F (121C – 148C). Bearing steel grows when heat is applied to it. It contracts to the original size, when cooled. Operating above the heat stabilization temperature may allow changes to the metallurgical structure, thus permanently deforming the product and limiting its ability to return to its original size. It also affects the hardness and operating clearances.

It is always important to examine the temperature limit of each component in a bearing. The component with the lowest temperature is the maximum limit at which the bearing can be operated at. As an example, the maximum temperature for a typical sealed bearing with nitrile rubber seals is 250F(121C). Therefore, a standard sealed bearing will not operate properly above 250F(121C). Don’t forget to include the grease or oil temperature limits into your analysis.

Bearing componentMaterialTemp Limits
Rings/BallsSAE 52100250F (121C) Max (Std Heat Treat)
 SAE 52100400F (204C)(Special Heat Treat)
 440C Stainless300F Max(Std Heat Treat)
 440C Stainless800F (Special Heat Treat)
 M50600F (Maximum)
SealsNitrile Rubber-70F to 250F
 Viton-40F to 400F
 Teflon-450F to 550F
Shields1010 steel450F Max
 302 stainless450F Max
Cages1010 steel450F Max
 302 stainless450F Max
 4340 steel575F Max
 Phenolic225F Max
 Nylon 6/6250F Max
 Nylon w/ moly disulfide200F Max
 Bronze/Brass450F Max
 PEEK or Vespel600F Max short term
 PEEK or Vespel480F Max long term

Related Reference Materials

  • Bearing Material Temperature Limits
  • Proper Bearing Handling
  • The Basics of Bearing Life
  • Solving Bearing Issues in
  • Electric Motors
  • Ceramic Hybrid Bearing
  • Performance Advantages