Learn about international weld quality standards including ISO 5817 and AWS D1.1. Discover inspection methods, acceptance criteria, and documentation requirements.
Introduction
Weld quality standards ensure consistency and reliability. At Fulei Metal, we work to international standards for our clients across Europe, North America, Japan, and beyond.
Major Welding Standards
ISO 5817
European standard for weld quality. Three quality levels: B (stringent), C (intermediate), D (moderate). Specifies acceptance criteria for imperfections.
ISO 3834
Quality requirements for fusion welding. Defines comprehensive quality management for welding.
AWS D1.1
American standard for structural steel welding. Defines weld types, inspection, and acceptance. Common for North American clients.
AWS D1.6
American standard for stainless steel welding. Similar structure to D1.1.
EN 1090
European standard for execution of steel structures. Includes welding requirements. CE marking requires compliance.
Quality Levels (ISO 5817)
Level B (Stringent)
For critical applications. Minimal imperfections allowed. Requires high skill and control. Aerospace, pressure vessels, critical structures.
Level C (Intermediate)
Standard quality level. Moderate imperfections allowed. Most industrial applications. General fabrication.
Level D (Moderate)
For non-critical applications. More imperfections allowed. Architectural, non-structural. Cost-effective.
Inspection Methods
Visual Inspection (VT)
100% of welds visually inspected. Checks: bead shape, size, undercut, overlap, surface cracks, spatter, cleanliness. First-line quality check. Requires good lighting and access.
Dye Penetrant Testing (PT)
Detects surface-breaking defects. Apply penetrant, remove excess, apply developer. Defects show as colored indications. Good for non-magnetic materials (stainless, aluminum).
Magnetic Particle Testing (MT)
Detects surface and near-surface cracks. Magnetize the part, apply iron particles. Particles cluster at defects. Ferromagnetic materials only (carbon steel).
Radiographic Testing (RT)
X-rays or gamma rays penetrate the weld. Defects show as dark or light areas on film. Detects internal porosity, lack of fusion, cracks. Expensive but comprehensive.
Ultrasonic Testing (UT)
Sound waves reflect off defects. Detects internal flaws. Good for thick sections. Requires skilled operator.
Acceptance Criteria
Crack Tolerance
No cracks accepted at any quality level. All cracks must be repaired.
Porosity Tolerance
Level B: minimal porosity, small diameter. Level C: moderate porosity. Level D: more porosity allowed. Specific limits depend on thickness and weld type.
Undercut Tolerance
Level B: max 0.5 mm depth. Level C: max 0.5-1.0 mm. Level D: max 1.0-1.5 mm.
Excess Weld Metal
Limits on reinforcement height. Typically 1-3 mm depending on thickness.
Documentation
Welding Procedure Specification (WPS)
Documents: process, base metal, filler metal, parameters, positions, gas. Ensures consistent quality. Required for certified welding.
Procedure Qualification Record (PQR)
Records actual parameters used for test weld. Includes test results. Validates the WPS.
Welder Qualification
Certifies welder skill. Test weld evaluated per standard. Periodic renewal required. At Fulei Metal, our welders are qualified to international standards.
Inspection Reports
Document: inspection method, results, acceptance level, inspector, date. Traceability for quality records. Provided to clients as required.
Conclusion
Weld quality standards ensure consistent, reliable welds. At Fulei Metal, our adherence to international standards and comprehensive inspection ensures welds meet client requirements.