UIC Leaflet 506: Standards for Railway Vehicle Wheels and Axles
UIC Leaflet 506 defines standards for railway vehicle wheels and axles, including dimensions, wear limits, and maintenance guidelines for safe and efficient train operations.

Introduction to UIC Leaflet 506
UIC Leaflet No: 506 is an international standard from the International Union of Railways (UIC) that specifies requirements for wheels and axles of railway rolling stock. It ensures safe operation, longevity, and interoperability across different rail networks.
Scope and Purpose
The leaflet provides guidelines for wheel and axle dimensions, tolerances, material properties, and wear limits. Its purpose is to maintain vehicle safety, optimize performance, and ensure compatibility with track and infrastructure.
Key Components
- Wheel Dimensions: Defines wheel diameter, flange height, tread profile, and tolerances for safe operation.
- Axle Standards: Specifies material requirements, strength, and mounting geometry for axles.
- Wear and Maintenance: Sets maximum wear limits and inspection intervals to prevent derailments and maintain stability.
- Testing Procedures: Standardizes measurements, load tests, and non-destructive testing for quality assurance.
Comparison Table
| Component | UIC 506 Requirement | Typical Practice |
|---|---|---|
| Wheel Diameter | 920–1050 mm (passenger coaches) | 900–1040 mm |
| Flange Height | ≥ 28 mm | ≈ 25–27 mm |
| Axle Material | High-strength steel, heat-treated | Various grades depending on manufacturer |
Implementation and Benefits
UIC Leaflet 506 is adopted by railway operators and manufacturers globally to ensure wheels and axles meet safety, wear, and performance standards. Implementation reduces derailment risks, enhances ride quality, and supports interoperability across networks.
Snippet Bait
UIC Leaflet 506 sets international standards for railway wheels and axles, defining dimensions, wear limits, and maintenance procedures for safe and reliable train operation.





