UIC Leaflet 805-70: The Standard for Railway Steel Supply and Quality Control

What is UIC Leaflet 805-70?

UIC Leaflet 805-70 is a fundamental quality standard titled “Technical specification for the supply of semi-finished products in steel for the construction of rolling stock.” It governs the procurement of the raw and semi-processed steel materials (such as billets, blooms, slabs, and bars) that are eventually forged or machined into critical train components.

Because railway vehicles operate under intense dynamic loads and varying climatic conditions, the “base” metal must be free from internal defects. UIC 805-70 ensures that the supply chain—from the steel mill to the manufacturer—adheres to strict metallurgical and administrative protocols.

Key Technical Delivery Conditions

The leaflet acts as a technical contract between the supplier and the railway undertaking. It focuses on three primary pillars of quality:

• Chemical Composition: Mandatory limits on elements such as carbon, phosphorus, and sulfur to ensure weldability and prevent cold brittleness.
• Internal Soundness: Requirements for Non-Destructive Testing (NDT), specifically ultrasonic testing, to detect microscopic inclusions or voids that could cause a component to snap under stress.
• Surface Quality: Standards for identifying and removing surface cracks or “scales” before the material is used in the final production of axles, frames, or engine components.

Material Traceability and Certification

A significant portion of UIC 805-70 is dedicated to Material Traceability. In the event of a structural failure in the field, the operator must be able to trace the component back to the specific “heat” (batch) of steel produced at the mill.

The standard mandates the use of inspection certificates (typically aligning with EN 10204 Type 3.1 or 3.2), which document the physical and chemical test results for every delivery. This level of documentation is a prerequisite for Quality Assurance (QA) in modern rolling stock maintenance and construction.

Comparison: UIC 805-70 vs. General Industrial Steel (EN 10025)

Modern Compliance and Evolution

While modern European procurement often references EN 10025 or ISO 630 for general steel, the 800-series UIC leaflets remain the definitive “Railway-Grade” overlay. They bridge the gap between general metallurgy and the specific, safety-critical needs of the rail sector. Adhering to UIC 805-70 is essential for manufacturers aiming for TSI (Technical Specifications for Interoperability) compliance in the structural sub-systems of new trains.