ISO 17635-2025 PDF

Full title and description

ISO 17635:2025 — Non‑destructive testing of welds — General rules for metallic materials. Guidance and general rules for selecting and applying NDT methods to welded metallic joints and for evaluation of results for quality control, taking into account material, weld thickness, welding process, quality requirements and extent of testing.

Abstract

This International Standard provides recommendations for the choice of non‑destructive testing (NDT) techniques for welds in metallic materials and for the interpretation and evaluation of NDT results for quality control purposes. It gives general rules for the selection of methods, testing levels and acceptance criteria, and aligns acceptance guidance with commonly used welding quality levels (e.g. those in ISO 5817 and ISO 10042) on a general basis. Annex A provides correlations between quality levels, testing levels and acceptance levels for specific techniques; Annex B gives an overview of standards related to techniques, testing and acceptance.

General information

• Status: Published
• Publication date: April 2025
• Publisher: International Organization for Standardization (ISO)
• ICS / categories: 25.160.40 (Welded joints and welds)
• Edition / version: 4th edition (2025)
• Number of pages: 15

Scope

ISO 17635:2025 applies to completed welds in metallic materials and provides guidance on selecting suitable NDT methods and on evaluating NDT results for quality control. The standard covers how material, weld thickness, welding process, required quality level and extent of testing influence method selection, specifies general rules and standards to be applied to different test types, and describes how acceptance levels relate to overall batch quality rather than being a direct one‑to‑one mapping from welding quality levels.

Key topics and requirements

• Principles for selecting appropriate NDT methods and combinations (visual, radiographic, ultrasonic, eddy‑current, magnetic‑particle, penetrant, leak and others) based on material, weld geometry and inspection objectives.
• Definition of testing levels and extent of examination relative to production batch, quality requirements and risk.
• Guidance on setting and applying acceptance levels for discontinuities (general alignment with ISO 5817 / ISO 10042 quality levels on a general basis).
• General rules for test technique application, technique‑specific considerations and recommended referenced standards for each technique.
• Recommendations on sampling strategies, documentation, reporting and recordkeeping for NDT of welds.
• References to competence and qualification of personnel (industry practice and relevant standards) and to laboratory/inspection body capabilities.
• Annex A: correlations between welding quality levels, testing levels and acceptance for selected techniques; Annex B: overview of standards linked to techniques and acceptance/testing levels.

Typical use and users

Used by welding engineers, NDT/inspection specialists, quality managers, fabricators, inspection and certification bodies, procurement and contract authors, designers specifying acceptance criteria, and regulatory or owner inspection teams. Typical applications include manufacture and inspection of pressure equipment, structural steel, pipelines, vessels, automotive and aerospace components where welded joints require standardized NDT selection and evaluation.

Related standards

Commonly used alongside ISO 5817 (quality levels for imperfections in fusion‑welded joints), ISO 10042 (quality levels for arc‑welded joints in aluminium), ISO 17637 (visual testing of fusion‑welded joints), ISO 9712 (qualification and certification of NDT personnel), ISO/IEC 17025 (laboratory competence) and quality management standards such as ISO 9001. Regional/adopted versions (EN/ISO, national adoptions) also exist.

Keywords

non‑destructive testing, NDT, weld inspection, weld acceptance, acceptance levels, testing levels, ultrasonic, radiographic, eddy‑current, magnetic particle, penetrant testing, visual testing, weld quality, ISO 17635

FAQ

Q: What is this standard?

A: ISO 17635:2025 is an international standard providing general rules and guidance for selecting and applying non‑destructive testing methods to welded joints in metallic materials and for evaluating the results for quality control purposes.

Q: What does it cover?

A: It covers guidance on choosing NDT methods and testing levels based on material, weld thickness and welding process, how to interpret results and apply acceptance guidance, and references to technique‑specific standards. It includes informative annexes correlating quality, testing and acceptance levels.

Q: Who typically uses it?

A: Welding engineers, NDT technicians and supervisors, QA/QC managers, inspection bodies, fabricators, designers and anyone specifying or performing weld inspection and acceptance activities.

Q: Is it current or superseded?

A: ISO 17635:2025 is the current (2025) edition; it supersedes earlier editions (for example the 2016 edition).

Q: Is it part of a series?

A: It is part of the ISO family of welding and NDT standards and is commonly used together with related standards such as ISO 5817, ISO 10042, ISO 17637 and personnel competence standards (e.g., ISO 9712).

Q: What are the key keywords?

A: NDT, weld inspection, acceptance levels, testing levels, ultrasonic, radiography, eddy‑current, magnetic particle, penetrant, visual testing, weld quality.