An unopened, unused bearing can remain in storage for several years. But if it is taken off the shelf after 5 years, can it still be installed without concern?
The age of the bearing alone is not enough to answer this question.
For longer storage periods, the condition of the packaging, storage conditions, bearing design, lubricant, and the manufacturer’s recommendations should all be considered when making a decision.
1. What Condition Is the Packaging In?
The original packaging is part of the bearing’s protection during storage. Therefore, whenever possible, the bearing should remain in its original, undamaged packaging until installation.
If the packaging has previously been opened, damaged, or exposed to moisture, the risk of contamination and corrosion may increase.
Unopened packaging is therefore a positive sign, but it does not by itself confirm that the bearing is suitable for use.
2. Under What Conditions Was It Stored?
There can be a significant difference between a bearing stored for five years in suitable warehouse conditions and one exposed to high humidity and significant temperature fluctuations over the same period.
High humidity and condensation caused by temperature changes can increase the risk of corrosion.
For the storage of rolling bearings, NTN recommends indoor storage at room temperature with relative humidity below 60%, while avoiding direct sunlight and condensation, among other factors.
FBJ recommends a dry, well-ventilated storage environment with relative humidity of no more than 60%, preferably at a temperature between 10 and 30 °C, while avoiding significant temperature fluctuations.
Specific requirements may vary, however, so the recommendations of the relevant manufacturer and product should always be followed.
3. The Type of Bearing Also Matters
Factory-greased and sealed bearings require particular attention.
During extended storage, not only the condition of the bearing’s metal components should be considered, but also the condition of the lubricant.
NTN-SNR technical documentation specifically points out that after a long storage period, the shelf life of the grease should also be taken into account, even if there are no visible signs of deterioration.
Therefore, two bearings of the same age but with different designs may not necessarily be assessed in the same way.
4. What Can the Condition of the Bearing Tell You?
Corrosion, discoloration, contamination, or other abnormalities can be warning signs.
Visual inspection is therefore an important part of the assessment, but it cannot answer every question.
Even if a bearing appears to be in perfect condition externally, this does not automatically mean that it is suitable for the intended application in every respect. With factory-greased bearings, for example, the condition of the lubricant cannot necessarily be determined through visual inspection alone.
5. What Does the Manufacturer Recommend?
Manufacturer recommendations clearly show why it is not advisable to rely on a single general “expiry date” for bearings.
NTN / NTN-SNR: for certain bearing units, the manufacturer allows for storage periods of several years under suitable conditions. It emphasizes the importance of original, undamaged packaging, appropriate temperature and humidity, and avoiding condensation, dust, and aggressive substances. For extended storage periods, the shelf life of the grease should also be taken into account.
FBJ: likewise emphasizes corrosion prevention, humidity control, and maintaining an appropriate warehouse temperature.
Manufacturer documentation therefore does not simply ask “How old is the bearing?” but considers the overall storage conditions.
How Should You Decide Whether to Use the Bearing?
For an older bearing, it is worth considering the following factors in this order:
Is its storage history known?
If it can be documented that the bearing was stored under suitable conditions and in its original, undamaged packaging, this is a positive starting point. If its storage history is unknown, there is greater uncertainty.
Did the storage conditions meet the manufacturer’s recommendations?
Rather than considering storage time alone, the actual storage conditions should be assessed against the manufacturer’s recommendations for the specific product.
Is it factory-greased?
If so, the shelf life of the lubricant should also be taken into account after an extended storage period.
Are there any visible abnormalities?
Damaged packaging, corrosion, contamination, or other signs of deterioration require further consideration.
What type of application will it be used in?
This also matters. A bearing in an easily accessible location presents a different level of risk from one used in a critical application where failure could result in significant downtime or other serious consequences.
A Simple Way to Prevent Old Stock from Accumulating: FIFO
It is worth preventing older stock from accumulating through effective inventory management.
The FIFO (First In, First Out) principle can help: whenever possible, bearings that arrived earlier should be used or sold first.
It is also advisable to monitor the age and turnover of inventory, keep bearings in their original packaging, and ensure dry, clean, and suitable storage conditions.
This reduces the likelihood of finding a bearing years later without knowing exactly how it was stored throughout that period.
Do You Need a New Bearing?
If you decide to replace an older bearing with a new one, search our product range by part number or technical parameters to find the right type.
If you need assistance selecting the right bearing or finding the appropriate design for a specific application, feel free to contact our team.
Frequently Asked Questions About Bearing Storage
How long can a bearing be stored?
There is no single storage period that applies to all bearings. Suitability for use depends on factors such as the bearing design, the condition of the packaging, the storage environment and, for factory-greased bearings, the shelf life of the lubricant.
For extended storage periods, always check the storage recommendations provided by the manufacturer for the specific product.
Can a bearing that has been stored for 5 years still be installed?
The fact that a bearing has been in storage for 5 years does not by itself determine whether it is suitable for use.
Factors to consider include the condition of the original packaging, storage conditions, bearing design, any signs of corrosion, and the manufacturer’s recommendations.
Does it matter if the bearing is still in its unopened packaging?
Yes. The original factory packaging is part of the bearing’s protection during storage.
Undamaged, unopened packaging is a positive starting point, but it does not by itself guarantee that a bearing stored for an extended period is suitable for installation.
What are the recommended storage conditions for bearings?
Bearings should be stored in their original packaging in a dry, clean environment with a reasonably stable temperature.
High humidity, condensation, significant temperature fluctuations, dust, and corrosive substances should be avoided. Specific storage requirements may vary between manufacturers and products.
Why is humidity important when storing bearings?
High humidity and condensation can increase the risk of corrosion on the metal surfaces of a bearing.
For this reason, bearing manufacturers’ storage recommendations generally address relative humidity and the importance of avoiding significant temperature fluctuations.
What should be considered when storing factory-greased bearings?
With factory-greased or sealed bearings, not only the condition of the metal components but also the ageing of the lubricant during storage should be considered.
After an extended storage period, the shelf life of the grease should therefore be checked according to the recommendations of the relevant manufacturer.
If there is no visible corrosion, is the bearing definitely suitable for installation?
Not necessarily. Corrosion, discoloration, or contamination can be important warning signs, but the absence of visible defects does not by itself confirm that a bearing stored for an extended period is suitable in every respect.
Factory-greased bearings in particular may involve factors that cannot be assessed through visual inspection alone.
What should I do if I need a new bearing instead of using an older one?
If you decide to use a new bearing, you can select the appropriate type by part number or technical parameters.
If you need assistance selecting the right new bearing for a specific application, contact the Bearing Kft. team.
