Overview
ISO 6520-1:2007 - "Welding and allied processes - Classification of geometric imperfections in metallic materials - Part 1: Fusion welding" - provides a standardized, precise system for identifying and describing weld imperfections produced by fusion welding. The document defines terminology, explains and illustrates geometric imperfections (metallurgical imperfections are excluded), and supplies a consistent designation method to avoid ambiguity in inspection, reporting, and documentation.
Key topics
- Scope and definitions: clear terms and limits for what constitutes a geometric imperfection in fusion welding.
- Classification and explanation: systematic categories of geometric imperfections with explanatory notes and illustrations where necessary to ensure unambiguous identification.
- Types of crack: dedicated classification and description of crack forms encountered in fusion welding.
- Designation rules: a consistent method for naming imperfections so engineers and inspectors use a common language.
- Informative annexes:
- Annex A covers cracking phenomena (informative guidance).
- Annex B provides correspondence between ISO 6520-1 and the alternative designation system in ISO/TS 17845, helping translate between classification schemes.
Practical applications
ISO 6520-1:2007 is a practical reference used to improve welding quality control and communication across industries. Typical uses include:
- Weld inspection and non-destructive testing (NDT) - provide consistent defect identification and reporting.
- Quality assurance and acceptance criteria - support preparation of inspection reports, weld maps and acceptance/rejection decisions.
- Welding procedure specification (WPS) and documentation - clarify imperfection definitions used in fabrication and contract specifications.
- Training and technical communication - supply standardized terminology and illustrations for welders, inspectors, and engineers.
- Design and fabrication reviews - ensure consistent interpretation of weld irregularities across suppliers and clients.
Who should use this standard
- Welding engineers and designers
- Quality control and NDT inspectors
- Fabricators and welding supervisors
- Certification bodies and auditors
- Technical authors preparing welding specifications and drawings
Related standards
- ISO/TS 17845 - alternative designation system for imperfections; Annex B in ISO 6520-1 shows correspondence between the two systems.
- ISO 6520 (Part 2) - covers classification of imperfections for welding with pressure (related part in the same series).
Using ISO 6520-1:2007 helps organizations standardize how weld geometry defects are described and reported, reducing misunderstandings and improving traceability of weld quality across projects and international supply chains.
Open preview (PDF)Welding and allied processes — Classification of geometric imperfections in metallic materials — Part 1: Fusion welding