When purchasing bearings, customers often ask, "How long is the warranty on these bearings?"
Because bearings are affected by operating conditions such as speed, load, operating temperature, dust, and lubrication conditions, there's no universal answer to this question, and we can't provide a warranty period.
For basic industrial components, the so-called warranty refers to the shelf life-how many years can they withstand wear and tear? This same question applies to bearings. In most cases, bearings aren't installed and used immediately after production. They undergo warehousing, transportation, and sales. Once they reach the user, they may not need them urgently. Instead, they are stored as spare parts and may be used later. This process can take anywhere from a few months to one or two years, or even five years.
So, under normal storage conditions, how many years can a bearing last without affecting its performance? Bearings are essential components, and they are also precision components, which place high demands on transportation and storage. So, how long can a bearing be stored? Let's take a look at the authoritative answer from SKF.
SKF first defines the storage life of bearings:
The storage life of bearings refers to the period of time during which bearings can be stored without adversely affecting their operating performance. Bearings are coated with high-quality rust-proof oil before leaving the factory to protect them from corrosion. Long-term storage is possible if bearings are stored in their original, unopened, undamaged packaging. The storage life of bearings also depends on the environmental conditions. The storage life of unsealed bearings is listed in the table below.
We all know that storage generally requires a cool, dry environment. But is this cool, dry environment quantifiable?
Let's return to this SKF table. First, we need to understand the concept of relative humidity. As we all know, rain falls when the air is saturated with water vapor. Relative humidity can be simply understood as the percentage of saturation water vapor in the air. To give you a more concrete understanding, let's first explain the basics: at room temperature, most mold cannot develop normally when the relative humidity is below 65%. Therefore, the value of 65% in the table is not randomly chosen. Due to dust in the air, condensation and rain are more likely to form when relative humidity reaches 80% or above, indicating extremely high humidity.
For the human body, experts believe that the upper limit of relative humidity should not exceed 80%, and the lower limit should not be less than 30%. The most suitable room temperature is 20°C and a relative humidity between 40% and 60%, at which point people are in good spirits and their thinking is most agile.
As can be seen, the table lists conditions under high humidity, which can also be understood as the lower limit of storage time. Bearings in relatively drier environments can have longer storage times.
In most areas of China, as long as they are not opened, bearings can be stored for 3-5 years without any problems.
Of course, there is an exception: bearings with sealing caps. The maximum storage time for sealed bearings is three years, not to prevent rust, but to prevent the deterioration of the pre-filled grease inside the bearings. Sealed bearings without lubrication holes should be used within three years. Sealed bearings with lubrication holes can be relubricated and continued to be used after the warranty period has expired.
In addition, to prevent bearing performance degradation during storage, please consider the following factors: First, store indoors in a frost-free, condensation-free environment, with a maximum room temperature not exceeding 40°C. Second, avoid drafts and avoid placing bearings in large aisles, where strong winds can easily cause evaporation of the anti-rust oil. Third, store bearings in a vibration-free environment, as vibration can damage the raceways. Fourth, store bearings horizontally to prevent damage from falling. Fifth, be sure not to open or damage the original packaging.
