is the international standard governing ultrasonic acceptance testing
for railway rolling stock materials, specifically focusing on tyres, axles, and wheels. ISO - International Organization for Standardization Key Overview Standard Name
: Railway rolling stock material — Ultrasonic acceptance testing. Latest Edition
: ISO 5948:2018 (3rd edition), which replaced the 1994 version. Primary Application
: It is used when product standards (like ISO 1005-1, -3, or -6) require mandatory ultrasonic tests or when optional tests are made mandatory by agreement. ISO - International Organization for Standardization Technical Scope & Requirements Components Covered
: Mainly rough-rolled or machined tyres, axles (solid and hollow), and wheels. Test Conditions
: Specifies pulse-echo ultrasonic instrument requirements (typically 1 MHz to 10 MHz) and probe selection. Testing Timing
: Generally performed after final heat treatment and before applying corrosion protection. Personnel Qualification : Operators must typically be qualified to or an equivalent standard. Acceptance Levels Discontinuity Detection
: Uses sensitivity settings based on reference reflectors (like a 3 mm flat-bottomed hole). Axle Permeability
: Determined by the height of the first back-wall echo, which usually must be of the screen height. High-Speed/High-Load
: The 2018 edition introduced stricter acceptance levels for rolling stock used in high-speed rail or heavy-load service. ISO - International Organization for Standardization Accessing the PDF
As a copyrighted document, the full text of ISO 5948 is not legally available for free download as a public PDF. You can preview or purchase the official version through the following platforms:
To understand why this standard matters, let's examine its core technical clauses (as found in the official ISO 5948 PDF).
When industry professionals search for "ISO 5948 PDF," they are looking for the portable, digital version of the standard. In a maintenance depot or manufacturing floor, having the PDF available on tablets or workstations allows technicians to instantly reference:
This immediate access to information reduces downtime and ensures that inspection procedures adhere strictly to international best practices.
A: No. ISO 5948 gives schematic diagrams (e.g., test setup for vibration), but not 3D CAD models of the lamp itself. You must design compliant hardware.
The standard categorized indications found during testing based on their appearance and size.
Many engineering universities and large railway companies have an institutional subscription to ISO standards. If you are a student or employee, check your internal intranet for a free, legal PDF download.
| Feature | Description | | :--- | :--- | | Standard | ISO 5948 | | Subject | Magnetic Particle Acceptance Testing for Railway Rolling Stock | | Status | Withdrawn | | Superseded By | EN 13698-2 (specifically for acceptance) and EN 13261/EN 13262 (product specs). | | Key Focus | Defining what constitutes a rejectable defect in steel axles, wheels, and frames. | | Industry | Railway / Mass Transit | iso 5948 pdf
Note for Engineers: If you are currently writing a procedure or specification, do not reference ISO 5948. You should reference EN 13698-2 for acceptance levels or the component-specific standards (EN 13261 for axles, EN 13262 for wheels) which contain the most up-to-date acceptance criteria tables.
ISO 5948:1994 is the international standard specifically governing the ultrasonic testing of railway rolling stock material, specifically for forged or rolled steel tires. What is ISO 5948?
This standard provides the technical requirements and acceptance criteria for ultrasonic examination. It ensures that the steel components used in train wheels (tires) are free from internal defects that could lead to catastrophic failure under the high-stress conditions of rail travel. Key Content of the Standard
Scope: Focuses on forged or rolled steel tires for railway vehicles.
Testing Procedures: Outlines the methods for manual or automated ultrasonic testing.
Equipment Requirements: Specifies the types of probes and calibration standards needed to ensure accuracy.
Acceptance Criteria: Defines the limits for "allowable" internal discontinuities and specifies what qualifies as a rejection. How to Access the PDF
Because ISO standards are protected by copyright, you generally cannot find a legal, free PDF download. You can obtain the official document through these channels:
ISO Store: The official ISO 5948:1994 page allows you to purchase and download the PDF directly.
National Standards Bodies: Many countries have their own portals (like ANSI in the US or BSI in the UK) that sell the document.
Industry Libraries: If you are working in engineering or manufacturing, your organization may have a subscription to standards databases like IHS Markit or ASTM Compass. Technical Context
ISO 5948 is often used alongside other railway standards, such as:
ISO 1005 Series: For railway rolling stock material (tyres, axles, and wheels). EN 13262: The European equivalent for wheel requirements.
ISO 5948 is the primary international standard for the ultrasonic acceptance testing of railway rolling stock materials, specifically focusing on critical components like wheels, axles, and tyres.
The latest version, ISO 5948:2018, outlines the rigorous Non-Destructive Testing (NDT) procedures required to ensure these components can withstand the extreme stresses of modern rail operations. Scope and Application
The standard provides a comprehensive framework for identifying internal discontinuities and assessing the "ultrasonic permeability" (the material's ability to transmit sound waves) of rail components.
Mandatory Testing: It is applied whenever product standards (such as ISO 1005-1, -3, or -6) require mandatory ultrasonic tests or when optional tests are specified in a contract.
Components Covered: Specifically applies to solid wheels, rough-rolled tyres, and both solid and hollow axles used in tractive and trailing rail stock. Key Technical Requirements of ISO 5948:2018 Technical Breakdown of ISO 5948 To understand why
The 2018 edition introduced several critical updates to accommodate high-speed and high-load rail environments.
Timing of Inspection: Testing must be performed after the final heat treatment but before any corrosion protection is applied. For axles, specific sequencing is required, such as testing permeability after end-facing but before final marking.
Equipment Standards: Pulse-echo ultrasonic instruments must be capable of operating within a 1 MHz to 10 MHz frequency range. Automated testing is highly preferred over manual methods for better accuracy.
Personnel Qualification: All personnel performing the tests must be qualified according to ISO 9712 or an equivalent standard recognized by both the manufacturer and the purchaser.
"Dead Zone" Limits: To ensure surface-level defects aren't missed, the standard limits the "dead zone" (the area where the probe cannot detect flaws) to typically 30 mm, with stricter limits of 10 mm for wheel treads. Evaluation Methods
ISO 5948 utilizes two primary methods for evaluating internal flaws:
DGS (Distance-Gain-Size) Method: Compares the echo height from a defect to a diagram to estimate its equivalent size.
DAC (Distance-Amplitude Curve) Method: Uses reference blocks with flat-bottomed holes to set a sensitivity curve for detecting discontinuities.
Permeability Assessment: Measures the height of the back-wall echo. For axles, a high back-wall echo (often at least 90% of screen height) is required to confirm the material's integrity. Why the ISO 5948 PDF is Critical for Safety ISO 5948:2018 - Ultrasonic acceptance testing
ISO 5948:2018 is the current international standard that defines the procedures and criteria for the ultrasonic acceptance testing
of railway rolling stock materials. It ensures that components like wheels, axles, and tyres are free from critical internal defects before they are put into service. ISO - International Organization for Standardization Core Purpose and Scope
The standard specifies how to perform non-destructive ultrasonic tests to detect internal discontinuities. It is primarily applied when product standards (such as ISO 1005-1 for tyres or ISO 1005-3
for axles) mandate such testing or when a purchaser specifically requests it during ordering. ISO - International Organization for Standardization Materials Covered : Tyres, axles (solid and hollow), and wheels. Key Objectives
Detecting internal discontinuities (cracks, inclusions, or voids). Determining the ultrasonic permeability
of axles to ensure the material allows sound waves to pass effectively for reliable testing. iTeh Standards Technical Requirements
The standard outlines the technical environment required for valid testing results: Personnel Qualifications
: Operators must be qualified and certified according to recognized NDT (non-destructive testing) standards. Equipment Specifications
: Defines the characteristics of the ultrasonic probes, transducers, and testing electronics. Calibration Calibration diagrams
: Use of reference blocks (specified in the document's annexes) to set testing sensitivity and evaluate discontinuity sizes. Testing Methods : Includes methods like the DGS (Distance Gain Size) diagram
or comparison of echo heights against reference echoes (back-wall echo or flat-bottomed holes) to estimate defect size. iTeh Standards Key Updates in the 2018 Edition
The third edition (2018) replaced the older 1994 version with several significant advancements: Hollow Axle Testing
: Introduced specific techniques for testing hollow axles, typically by inserting probes into the central bore. High-Speed Requirements
: Added more stringent acceptance levels for components used in high-speed trains or under heavy axle loads. Standardization
: Updated normative references to align with current international safety and quality standards. iTeh Standards Purchasing and Access INTERNATIONAL STANDARD ISO 5948
ISO 5948 is the international standard for the ultrasonic acceptance testing of railway rolling stock materials, such as wheels, tyres, and axles.
The current version is ISO 5948:2018, which replaced the 1994 edition. 🛠️ Key Technical Requirements
The standard ensures components are free from internal defects like cracks or hydrogen flakes using pulse-echo ultrasonic instruments (1 MHz to 10 MHz).
Acceptance Levels: Defects are typically measured against a flat-bottomed hole (FBH) reference. For high-speed wheels, the allowable diameter may be as small as 2 mm.
Permeability: For axles, the first backwall echo must generally be ≥ 90% of the screen height to ensure the material is "transparent" to ultrasound.
Dead Zones: Testing must limit "dead zones" (areas where defects can't be seen) to specific depths, such as 10 mm for wheel treads. Major Updates in the 2018 Edition
The 2018 revision introduced several critical updates over the 1994 version:
Hollow Axles: Now includes specific testing procedures for hollow-axle bores.
Stricter Criteria: Added more stringent acceptance levels for high-speed and high-load trains.
Permeability Reference Blocks: Introduces new techniques and reference blocks for determining axle permeability. 📥 Where to Access the PDF
Official copies must be purchased from authorized distributors; they are rarely available for free legally due to copyright. Official Source: ISO Store - ISO 5948:2018
National Bodies: Available via the ANSI Webstore or iTeh Standards.
Preview: You can view the Table of Contents and Foreword for free on the ISO Online Browsing Platform. ISO/DIS 5948(en), Railway rolling stock material