ISO 21433:2025

Overview

ISO 21433:2025 - Plain bearings - Handling of plain bearings provides requirements and practical guidance for the safe and effective storage, transportation, handling, installation, operation and replacement of plain bearings and related parts. The second edition updates terminology and clarifies best practices to prevent damage, contamination and premature failure during the lifecycle from manufacture to replacement.

Key topics and requirements

• Scope and normative reference
  • Applies to plain bearings and related parts; uses terms from ISO 4378-1.
• Storage and transportation
  • Protection against damage, deformation, dust, moisture and corrosion during storage and transit.
  • Use of suitable packing materials (rust inhibitor paper, oil‑impregnated paper, polyethylene, foamed buffers) and robust packaging that is clearly labelled (type, part number, lot, quantity).
  • Guidance on container use (cardboard, plastic, metal) to prevent scattering, shock damage and contamination.
  • First‑in, first‑out inventory practice and appropriate ambient temperature/humidity control.
• Packing and unpacking
  • Packing methods must keep bearings secure yet allow safe unpacking for inspection/installation.
  • Avoid materials that shed fibres or produce dust; prevent damage from sharp tools when opening packages.
• Selection of rust inhibitors and cleaning agents
  • Choose inhibitors/cleaners compatible with bearing materials and downstream processes (oil-free packaging options and deoxidizing agents noted).
• Handling and documentation
  • Procedures to avoid contamination and deformation; retain test and quality certificates with shipments.
• Installation (fitting)
  • Accepted fitting methods are described including press‑fit, screw fixing, keyed joints, retaining rings, and shrink fitting (by cooling or heating).
  • Post‑installation checks: mating shaft inspection, assembly verification and operational checks.
• Operation
  • Lubrication system flushing/cleaning, running‑in procedures and monitoring/supervision (control items and record keeping).
• Replacement
  • Guidance on dismounting and replacing bearings with new units to maintain reliability.

Applications and users

ISO 21433:2025 is intended for:

• Bearing manufacturers and suppliers (packing, labeling and shipping practices)
• OEM design and assembly teams (fitting methods and mating-shaft requirements)
• Maintenance and reliability engineers (operation, running‑in, replacement and inspection)
• Warehouse, logistics and quality assurance personnel (storage environment, traceability and documentation)
• Integrators of automated assembly systems (container design agreements)

Related standards

• ISO 4378-1 - Terms, definitions and bearing material properties (normative reference)
• ISO 12843 - (referenced in Bibliography)
• ISO 14001 - Environmental management considerations for packaging

ISO 21433:2025 helps reduce bearing failure risk, improve lifecycle reliability and standardize handling across supply chains - essential for engineers and logistics teams working with plain bearings.