ISO 6520-2:2013

Overview

ISO 6520-2:2013 - Welding and allied processes: Classification of geometric imperfections in metallic materials - Part 2: Welding with pressure defines a uniform system to identify and name geometric imperfections that arise specifically from welding processes performed under pressure (press welding). The standard focuses only on the type, shape and dimensions of these imperfections and provides a consistent designation system for reporting and documentation. It does not address metallurgical deviations, causes outside the welding operation (e.g., environmental damage, applied loads), nor the structural consequences or acceptance criteria for those imperfections.

Key topics and technical requirements

• Scope and limitations: Only imperfections caused by welding with pressure are classified; metallurgical issues and external damage are excluded. The standard explicitly does not give guidance on consequence assessment or acceptance criteria.
• Classification structure: Imperfections are grouped into six main classes:
  • P1 - Cracks
  • P2 - Cavities
  • P3 - Solid inclusions
  • P4 - Lack of fusion
  • P5 - Imperfect shape
  • P6 - Any other imperfections not in P1–P5
  • (The letter “P” denotes welding with pressure.)
• Designation and numbering: A uniform designation and a multi‑digit reference numbering system (three figures for principal imperfection; additional figures for sub-terms) are specified; the numbering follows the approach used in ISO 6520-1.
• Documentation format: Table 1 in the standard provides reference numbers, multilingual designations (English, French, German), explanations and, where necessary, illustrative figures to clarify defect forms.
• Normative references and editorial notes: The document is part of the ISO 6520 series and aligns with ISO/TC 44 terminology and representation rules.

Practical applications and who uses it

ISO 6520-2:2013 is a reference tool used to standardize the way welding-with-pressure imperfections are described and recorded across industries:

• Welding engineers and designers - to specify defect reporting language in fabrication documentation.
• Quality control and inspection teams - to classify and record observed geometric imperfections consistently during visual inspection and non-destructive testing (NDT).
• NDT technicians and inspectors - to annotate reports and link detected anomalies to a recognized defect taxonomy.
• Procurement and contract writers - to reference a common defect nomenclature in acceptance and inspection clauses.
• Standards writers and trainers - to harmonize terminology and instructional materials.

Note: For fusion-welding defect classification, refer to ISO 6520-1; ISO 6520-2 is specifically for press-welding contexts.

Related standards

• ISO 6520-1 - Welding and allied processes - Classification of geometric imperfections - Part 1: Fusion welding (numbering system alignment and complementary scope)
• ISO/TC 44 (Welding and allied processes) publications for related terminology and representation guidance

Keywords: ISO 6520-2:2013, welding with pressure, press welding, classification of geometric imperfections, weld defects, welding inspection, NDT, welding quality.