Overview
ISO 12940-2:2026 is an international standard developed by ISO that outlines a specific method for determining the roll stability of lubricating greases under wet conditions. The procedure evaluates changes in grease consistency-measured by cone penetration-when the product is worked in a roll stability test apparatus in the presence of water. This method applies to greases with cone penetration values ranging from 175 × 0.1 mm to 385 × 0.1 mm, as specified by ISO 2137.
This standard is vital for manufacturers, suppliers, and users of lubricating greases, offering an objective and comparative way to assess how exposure to water affects grease performance, consistency, and ultimately, suitability for practical applications.
Key Topics
- Roll Stability in Wet Conditions: The test simulates real-world environments where lubricating grease may be exposed to water, influencing its physical properties.
- Consistency Measurement: Changes in grease consistency are quantified using worked cone penetration before and after exposure to wet rolling conditions.
- Applicability: The standard is relevant to a wide range of grease types within the specified penetration range, supporting product development, quality control, and specification compliance.
- Testing Procedures:
- Grease samples are prepared with water using standardized methods to ensure consistent and homogeneous mixtures.
- The roll stability apparatus subjects the sample to a defined combination of shear and temperature, either at ambient conditions or elevated temperatures.
- Post-test, the consistency is remeasured, and results are compared to pre-test values.
- Reporting and Repeatability: The standard provides guidance for consistent reporting, including test conditions, sample identification, deviations, and observations of physical changes.
Applications
ISO 12940-2:2026 is essential in several key areas:
- Product Development and R&D: Laboratories and manufacturers use the method to evaluate new grease formulations and understand how water exposure impacts performance.
- Quality Control and Specification Compliance: Routine batch testing ensures finished products meet technical requirements and perform reliably in wet environments.
- Industrial Sectors:
- Automotive and Heavy Machinery: For bearings and components exposed to water, such as wheel bearings, marine equipment, and off-road vehicles.
- Steel and Pulp & Paper Industries: Where process equipment operates in high-moisture environments.
- Comparative Benchmarking: Enables clear comparisons between different grease products, supporting purchasing decisions and supplier evaluations.
By adopting ISO 12940-2:2026, organizations can minimize the risk of equipment failure due to improper grease selection, improve machinery life, and document compliance with best practices for lubricant testing.
Related Standards
- ISO 2137: Methods for determining the cone penetration of lubricating greases and petrolatum.
- ISO 11009: Evaluation of grease resistance to water washout in bearings.
- ISO 11007-1 and ISO/TS 11007-2: Determination of rust-prevention characteristics of lubricating greases under dynamic wet conditions and with water wash-out.
- ASTM D7342, ISO 12921, NF T60-626: Additional methods for assessing grease stability in the presence of water.
- ISO 23572: Sampling of lubricating greases for testing purposes.
These complementary standards provide a comprehensive framework for characterizing the behavior of lubricating greases, particularly under challenging conditions involving water exposure.
By implementing ISO 12940-2:2026, stakeholders in the lubricants industry ensure robust, repeatable, and globally recognized evaluation of grease roll stability under wet conditions, supporting operational reliability across diverse sectors.
Open preview (PDF)Petroleum products and lubricants — Determination of roll stability of lubricating grease — Part 2: Wet condition test
