examined by NTN

How can you understand and avoid bearing failures when operating?
Do you want to try a new service?
Call on the expertise of NTN.


The EXPERT APPRAISAL service from NTN analyses your bearings and answers all your questions:

  • What are the causes of operational failure?
  • Can the bearings be repaired?
  • What is the best way to avoid failure again?

Integrated into your maintenance plan, our recommendations can increase the service life of bearings, optimize the usage of your machines and therefore, save money.

If in doubt, NTN will provide you with technical assistance for your maintenance operations.

Also consult our pages on mounting, dismounting and lubrication.

  1. Receiving a failing product results in the opening of a case.
  2. NTN commits to understand the application.
  3. An experienced technician dismantles the product and carries out appraisal of the bearing: visual inspections, dimensional measurements, analysis of the lubricant if necessary, or even metallurgical analysis.
  4. The expert diagnoses the likely causes of the failure.
  5. The diagnosis is discussed and confirmed in a multidisciplinary session
  6. The diagnosis and recommendations are provided in an expert appraisal report which is sent to you. The recommendations relate both to the bearing and its mounting on the machine in which it is used.

This process will also be used to analyse products used in tests. In this case, our expert knowledge will improve the product or manufacturing process.

Aircraft bearings can be subject to specific process.

Pierre B.

For many years, we have had a problem with high consumption of ball bearings used in a high speed application
NTN offered to undertake a comprehensive appraisal of several bearings to try and solve this recurring problem. The diagnosis highlighted:

  • a lubrication problem, but that was not the main cause of the failure
  • a locking problem with the inner ring on the shaft

In discussions with maintenance and the NTN technician, it turned out that the bearing was not locked down firmly enough and so loosened after a few hours of operation. This approach has allowed us to increase the utilisation rate of the machines and therefore the level of production.

Pierre B., Maintenance Manager in consumer goods manufacturing industry. NTN signed a contract of confidentiality with this customer.

Would you like an expert appraisal of your bearings? CONTACT US