ISO 7146-1:2019

Overview - ISO 7146-1:2019 (Plain bearings - Part 1: General)

ISO 7146-1:2019 defines, describes and classifies the visual and physical damage characteristics that occur in service on metallic, hydrodynamically lubricated plain bearings and journals. The standard focuses on damage forms with a well-defined appearance that can be attributed to likely causes with a high degree of certainty. It illustrates various appearances using photographs and diagrams and provides practical guidance for consistent damage characterization and analysis.

Keywords: ISO 7146-1:2019, plain bearings, hydrodynamic bearings, metallic plain bearings, bearing damage, damage characterization, bearing inspection, tribology, failure analysis.

Key topics and technical content

• Definitions and terminology related to bearing damage and indicators of damage.
• Systematic description of damage causes and their characteristic appearances, including:
  • Static overload and dynamic overload
  • Wear by friction
  • Overheating
  • Insufficient lubrication (starvation)
  • Contamination (particles and chemicals)
  • Cavitation erosion
  • Electroerosion
  • Hydrogen diffusion
  • Bond failure
• Relationship between observed appearance and probable cause (damage characterization).
• Detailed sections on:
  • Damage to the bearing surface (typical appearances, possible causes, examples)
  • Damage to the bearing back (including dynamic overload and wear)
  • Special positions of damage appearances
• Practical guidelines for damage analysis, organized into a stepwise procedure (Step 1 through Step 5) to support systematic investigations.
• Illustrative content: photographs, diagrams and an informative annex with example use of tabular guidance.

Practical applications - who uses this standard

• Maintenance and reliability engineers conducting root-cause analysis of bearing failures.
• Tribologists and failure analysts diagnosing wear, erosion, contamination and electrochemical damage.
• OEMs and design engineers specifying bearing materials and lubrication systems for rotating machinery.
• Inspection teams, asset managers and laboratory technicians preparing visual and photographic reports for warranty or forensic investigations.
• Training and quality assurance programs aiming for consistent classification and reporting of bearing damage.

Related standards and notes

• ISO 7146-1:2019 is Part 1 (General) of the ISO 7146 series; consult other parts of the series and related ISO standards on bearings and lubrication for complementary test methods, dimensional standards and material specifications.
• The document is primarily a descriptive and diagnostic aid - it does not replace test procedures but supports consistent visual classification and interpretation of bearing damage.

For reliable bearing maintenance, use ISO 7146-1:2019 together with machine-specific maintenance practices, lubricant specifications and material data to achieve accurate failure diagnosis and effective corrective actions.