Ultra Low Temperature Bearings (Down to -250°C) are precision components engineered to maintain reliable operation in cryogenic and extreme cold environments where conventional bearing materials become brittle, lubricants solidify, and clearances shrink unpredictably. These bearings are critical for applications in liquid nitrogen (-196°C), liquid hydrogen (-253°C), and liquid helium (-269°C) systems.
Low Temp. -250°C Bearings
Characteristics: AISI 304 or Invar raceways; self-lubricating PTFE or MoS2; no ferromagnetic phases; silicon nitride balls.
Advantages: Operates in liquid helium or nitrogen (cryogenic pumps, space actuators) where standard 52100 steel becomes brittle (fracture at -100°C). Life >5000 cycles from 293K to 20K.
Technical Ceiling: Impact toughness maintained at >15 J/cm² at -250°C; thermal contraction difference (shaft vs. bearing) must be matched; maximum speed 1 m/s.
Caution: Standard bearings will shatter at -250°C due to retained austenite transformation. Material must be fully austenitic. Grease freezes – use solid lubricant. Must allow 0.3 mm cold clearance at room temperature.
