Overview
ISO 12940-1:2026 is an international standard developed by ISO that outlines a laboratory method for assessing the roll stability of lubricating greases under dry conditions. The standard is titled "Petroleum products and lubricants - Determination of roll stability of lubricating grease - Part 1: Dry condition test." It specifically addresses the evaluation of changes in grease consistency, as measured by cone penetration, after mechanical working in a roll stability test apparatus. This testing method applies to lubricating greases with cone penetration values between 175 × 0.1 mm and 385 × 0.1 mm, in accordance with ISO 2137.
The roll stability test is crucial for quality assurance, product development, and performance specification of lubricating greases used in various industrial and automotive applications. Proper grease selection and validation help ensure optimal mechanical stability, reducing equipment wear and maintenance costs.
Key Topics
- Test Scope: The standard applies to lubricating greases within a defined penetration range, as determined by ISO 2137.
- Principle: Grease samples are worked under controlled shear conditions using a standardized roll stability apparatus, simulating the mechanical stresses encountered in real-world bearing and gearbox environments.
- Testing Procedure:
- Preparation involves weighing and spreading the grease inside a steel cylinder, introducing a weighted roller, and subjecting the sample to a specified rotation speed.
- The test can be conducted at ambient temperature (Condition A) or at elevated temperature for extended periods (Condition B).
- After the test, cone penetration is measured again to determine the change in consistency.
- Evaluation and Results: The change in penetration value indicates the mechanical stability of the grease-whether it has softened or hardened due to rolling.
- Precision: Repeatability and reproducibility are defined, supporting consistent, comparable results across different laboratories and applications.
- Safety Considerations: Users must observe appropriate safety measures when handling samples and operating equipment.
Applications
ISO 12940-1:2026 provides significant practical value across industries that depend on lubricating greases for protection and performance of mechanical equipment. Typical applications include:
- Industrial Bearings: Ensuring that lubricating grease maintains appropriate consistency under rolling or shearing forces helps prevent premature bearing failure.
- Automotive Industry: Vehicle wheel bearings and gearboxes rely on stable lubricants; this standard aids in selecting and validating products for long-term operation.
- Product Development and Quality Control: Manufacturers use the roll stability test to develop new greases and verify product batches for mechanical stability before market release.
- Specification and Compliance: The standard provides a uniform methodology for suppliers and buyers to certify products for use in demanding environments.
The ability to accurately assess the roll stability of lubricating grease supports maintenance planning, reduces downtime, and enhances equipment life.
Related Standards
ISO 12940-1:2026 references other international standards and widely recognized test methods to ensure thorough and compatible testing protocols:
- ISO 2137: Petroleum products and lubricants - Determination of cone penetration of lubricating greases and petrolatum. This defines the procedure for measuring the cone penetration values essential for assessing grease consistency.
- ISO 23572: Petroleum products - Lubricating greases - Sampling of greases. It outlines the correct sampling methods to ensure representative testing.
- ASTM D1263: Addresses leakage tendencies of automotive wheel bearing greases.
- ASTM D1831: Covers roll stability testing methods similar in purpose to ISO 12940-1.
- NF T60-190: Specifies rolling stability testing for lubricating greases.
- ISO 4259-1: Explains the statistical treatment of test method precision, referenced for repeatability and reproducibility calculations.
By adhering to ISO 12940-1:2026, industries achieve a higher level of confidence in the mechanical stability and operational performance of lubricating greases, underlining safety, efficiency, and global market acceptance.