Counterfeit bearings – know the risks

The relentless drive to remain competitive and profitable has created a culture where too many companies are forced into making purchase decisions based solely on unit price, ignoring other factors such as total cost of ownership (TCO) and performance. However, shopping around for irresistible bargains often comes at a far higher price, with many purchasing and engineering teams unaware of the risks and dangers involved from adopting such a strategy.

The end result is usually the inadvertent acquisition and arrival of counterfeit bearings. Although the price may have been cheaper, in reality the overall cost is likely to be considerably greater. For a start, these poor-quality fakes fail more frequently when put into service, increasing maintenance and downtime costs. It should also be noted that these costs invariably far exceed the amount saved on the initial purchase.

The origins of counterfeits

Counterfeit bearings tend to originate from uncontrolled sources in countries with low-cost economies, where disingenuous organisations use lower-grade materials that are usually processed on ageing machines operated by low-paid, unskilled operatives. The bearings, which are often poorly handled and stored, are then placed in boxes designed to resemble the packaging of the manufacturer being replicated, completely disguising the inauthenticity of the product to cheat both purchasers and users.

Inconsistent quality is assured when buying bogus bearings. Such bearings may last long enough to pass pre-production trials, but their subsequent premature failure in the field will cast uncertainty over the performance of the machine, system or vehicle to which they are fitted. This eventuality can compromise brand reputation and damage sales.

Many companies finding themselves in this situation will call for help, only to discover a complete absence of technical support or advice. Typically, counterfeiters will not have local application engineers available to help with questions, nor will there be any modern, wellequipped technology centres to provide test data, product defect assessments or failure analysis.

Material matters

The materials used to produce fake bearings are not of the quality provided by OEM suppliers such as NSK, which leverages decades of experience in materials science to ensure its bearings exceed the demands of modern industrial applications. Steel quality is the major factor in bearing reliability, where a difference in operating life of up to 20 times (between genuine and counterfeit) is not uncommon.

The fatigue life of alloyed bearing steels such as 100 Cr6 (or SUJ2 in the Japanese standard) depends principally on the inclusion content. Oxide or non-metallic inclusions, in particular, promote negative effects under the raceway surface. As an example, it is known that aluminium oxide inclusions, which are formed via oxidisation during the melt, can lead to a major reduction in bearing fatigue life. This effect is created because aluminium oxide inclusions are relatively hard and can break up when steel undergoes processes such as forging. During break-up, inclusions shrink and weaken the microstructure. Working with a leading steel manufacturer, NSK has developed materials like Z Steel, EP Steel and BNEQARTET to prevent this negative effect. The company also uses special melting processes that reduce non-metallic content and prolong fatigue life.

With counterfeits, heat treatment is another factor that is often absent or poorly applied, compromising the specific characteristics of steels and, consequently, bearings. Materials such as NSK’s SHX steel are subjected to a specific heat treatment that is particularly resistant to wear at high operating temperatures. Bearings of this type are required not just when heat is present as an inherent part of the process, but in applications such as machine tools, where fast spindle speeds generate high temperatures in the drive components. During development, the characteristics of SHX steel were proven by means of comprehensive wear resistance and surface fatigue life tests. Counterfeit manufacturers do not offer this kind of product development and analysis.

The fight continues

Although NSK continues to invest extensively in efforts to identify and prosecute counterfeiters, the advice is clear: when purchasing NSK products, customers should exercise due caution. Only buy from trusted sources such as Authorised NSK Distributors. Additional information about the fake bearings industry can be found at www.stopfakebearings.com