What is ISO 21250-1 about?
ISO 21250-1 is the first part of the multi-series of International Standard on roll bearings.
ISO 21250-1 is applicable to the rolling bearings for noise testing of rolling bearing greases
ISO 21250-1 specifies:
- Basic principles, testing assembly and the test machine for noise testing of rolling bearing greases
- Symbols used in the test methods BQ+, MQ and NQ
Note: ISO 21250-1 is applicable for testing rolling bearing greases, especially of unused grease.
Note: Suitable greases are greases of NLGI classes 1 to 3 according to DIN 51818. Suitable greases for lubrication of rolling bearings are especially greased according to ISO 12924. The test method according to this document delivers meaningful results for rolling bearings; however, it can also be applied for greases in similar applications.
Who is ISO 21250-1 for?
ISO 21250-1 on noise testing of rolling bearing greases is useful for:
- Manufacturers of rolling bearings
- Automotive industry
- Lubricant manufacturers
- Electrical engineers 
- Mechanical engineers
Why should you use ISO 21250-1?
For long service-life and low noise performance of roll bearings, methods to verify the cleanliness and lubrication performance are critical.
The method described in ISO 21250-1 for determining the purity grade of bearing grease is influenced by thickeners, base oils, additives, and solid lubricant additives, as well as the manufacturing process, and this is reflected in the running noise. As a result, rolling bearing grease noise testing is advised.
Furthermore, ISO 21250-1 grease noise testing enables grease makers to design low-noise lubricants with improved damping qualities.
ISO 21250-1 can also help rolling bearing manufacturers and end-users choose low noise grease with improved damping qualities.
ISO 21250-1 specifies the basic concepts, standards for the testing assembly, and test machine used to jointly determine and assess the noise characteristics of bearing grease.
This will assist you in determining the quality of grease noise or selecting low-noise (quieter) greases. Ultimately, you will be able to avoid incidence of high fatigue life of bearings. If you are a bearing producer, ISO 21250-1 will help you select the right grease
