Why Are Bearings Frozen Before Installation

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1 Why Are Bearings Frozen Before Installation

1.1 Why freeze bearings？

1.2 How to freeze bearings？

1.3 Which bearings can be frozen？

1.4 How to select bearing freezing equipment？

1.5 Conclusion

1.6 Related freezers

1.7 CONTACT US

Bearings are critical components that allow machinery to rotate smoothly. They are widely used in automobiles, household appliances, and industrial equipment.

To facilitate easier installation, bearings are often pre-frozen before assembly. But why? In this article, we’ll uncover the little-known reasons behind this practice.

Why freeze bearings？

When temperature changes, the volume of most materials changes as well—a concept known as thermal expansion and contraction. Metals also exhibit this behavior, though the change in size is usually tiny and not visible to the naked eye.

For example, a 60°C drop in temperature may only cause a shrinkage of a few microns. While this may seem negligible, such tiny differences can significantly impact precision mechanical assemblies. At room temperature, the inner diameter of a bearing is slightly smaller than the shaft it’s mounted on. This creates a tight interference fit, which prevents the bearing from slipping during operation.

However, this tight fit can make installation difficult. To solve this, engineers take advantage of the metal’s contraction at low temperatures. By freezing the bearing, its inner diameter increases just enough to allow easier mounting without forcing or damaging it.

Since most bearings are made of steel or alloy with relatively stable thermal expansion coefficients, the effect of freezing can be accurately controlled. Once installed, the bearing warms back to room temperature and regains its original size—creating a tight and secure fit on the shaft.

How to freeze bearings？

To freeze a bearing, you need suitable refrigeration equipment. The most commonly used tool is an industrial freezer, which can lower the temperature to between -30°C and -80°C. Some specialized models can even reach -180°C.Make sure the freezer is large enough to accommodate the size of your bearing.

The bearing should be clean and free of oil or moisture—otherwise, it could be damaged during freezing. Not all bearings are suitable for freezing. You should set the appropriate temperature and freezing time based on the bearing’s material and size.

Once placed in the freezer, close the door tightly and start the machine. Avoid opening the door frequently, as it may cause ice buildup and temperature fluctuations. Typically, bearings are frozen for 1 to 4 hours, depending on the size. After freezing, assemble the bearing as soon as possible before it warms up.During operation, always wear gloves and monitor temperature conditions to ensure safety and proper handling.

Which bearings can be frozen？

Not all bearings need to be frozen, but the following types benefit the most from this treatment:

• Large Bearings
Typically used in wind turbines, mining equipment, and other heavy machinery. These bearings often exceed several hundred millimeters in diameter.

• Heavy-Load Bearings
Designed to withstand extreme pressure and stress, such as those in ship propulsion systems and steel rolling mills.

• High-Speed Precision Bearings
Common in aerospace systems and machine tool spindles where precise alignment is critical.

• Bearings Made of Special Materials
Such as high-alloy or custom steel components that require exact interference fits.

How to select bearing freezing equipment？

When selecting a bearing freezing system, consider the following factors:

• Temperature Range
Different bearing types require different freezing temperatures. Most industrial bearings need freezing temperatures between 30°C and 80°C.

• Freezer Size & Capacity
Ensure the chamber is large enough to accommodate your bearings with space for proper airflow. If you need to freeze multiple bearings simultaneously, choose a model with high capacity.

• Temperature Control Accuracy & Uniformity
Precise temperature control prevents uneven freezing, which could affect the final fit and damage the bearing.

• Cooling Speed
Faster cooling improves productivity but may increase power consumption. Match cooling speed to your production schedule.

• Safety Features
Look for systems with automatic alarms, overcooling protection, and thermal monitoring to ensure safe operation.

• Level of Automation
Automated control systems reduce manual labor, improve safety, and make processes easier to manage.

• Manufacturer Reputation
Choose a manufacturer with proven expertise in industrial refrigeration. Experienced suppliers offer better support and long-term reliability.

Conclusion

Freezing bearings makes installation easier, more precise, and safer—especially for large or heavy duty components. If you’re facing difficulties during bearing assembly, investing in a dedicated industrial freezer might be the solution.

At LNEYA, we offer a wide range of industrial freezers and custom refrigeration solutions. Our experts are ready to help you select the right model based on your application needs.[Click here] to simplify your bearing freezing pro