BS EN ISO 5173: Guided Bend Testing for Metallic Welds

BS EN ISO 5173 is a European Standard titled "Resistance welding - Spot welding of aluminum and aluminum alloys - Weldability, welding and testing". It specifies the requirements for the spot welding of aluminum and aluminum alloys using resistance welding.

Talk to an Expert

BS EN ISO 5173: Guided Bend Testing for Metallic Welds

TRUSTED BY

Precision-driven testing for dimensional accuracy and compliance

Overview
Scope, Applications, and Benefits
Test Process
Specifications
Instrumentation
Results and Deliverables

Overview

BS EN ISO 5173 is a standard test procedure that examines the ductility and the soundness of the welds in metals through a test procedure called the guided bend test. It examines the weld and the heat-affected zone’s ability to bend without cracking when subjected to stress.

The test procedure involves bending the weld sample around a fixed mandrel using the guided bending test. It involves the examination of the surface of the weld for signs of cracks that may be associated with welding defects such as poor fusion, slag inclusions, and porosity.

Scope, Applications, and Benefits

Scope

BS EN ISO 5173 specifies a testing method that assesses the ductility and soundness of the weld joint by bending the joint. The welding structures covered by this standard are metallic weld joints, butt welds, fillets, fusion weld joints, weld procedure qualification tests, and welder qualification tests. The bending test is used to determine if the weld joint is capable of deforming without cracking. This is significant information regarding the weld joint.

The key aspects covered by this standard are:

– Ductility of the weld
– Soundness of the weld
– Performance in the HAZ
– The presence of weld discontinuities

Applications

Weld procedure qualification testing (WPQT)
Welder qualification and certification
Structural steel fabrication
Pressure vessel manufacturing
Pipeline welding inspection
Shipbuilding and offshore structures
Heavy engineering industries

Benefits

Verifies weld ductility and flexibility
Detects weld defects and discontinuities
Ensures welding process reliability
Supports weld procedure qualification
Improves the structural integrity of welded components
Provides standardised testing for weld quality
Enhances safety and compliance with welding standards

Test Process

Specimen Preparation

A welded test coupon is machined into a bend specimen with the weld positioned at the centre.

Fixture Setup

The specimen is placed in a guided bend test fixture with a specified mandrel and supports.

Bending Operation

Force is applied to bend the specimen around the mandrel to the required angle.

Inspection & Evaluation

The bent surface is inspected for cracks or discontinuities and assessed against acceptance criteria.

Technical Specifications

Parameter	Details
Applicable Materials	Welded metallic materials and joints
Specimen Types	Face bend, root bend, and side bend specimens
Bend Angle	Typically up to 180°
Mandrel Diameter	Specified based on material thickness and welding standard
Evaluation Method	Visual inspection of outer bend surface
Output Units	Pass / Fail based on crack or discontinuity limits

Instrumentation Used for Testing

Guided bend test fixture
Universal testing machine or bend testing machine
Mandrels of specified diameter
Specimen supports and rollers
Precision cutting and machining tools
Surface inspection tools
Measuring instruments
Documentation and reporting software

Results and Deliverables

Pass/fail evaluation of weld ductility
Detection of cracks or weld discontinuities
Assessment of weld metal and heat-affected zone integrity
Weld procedure qualification documentation
Welder qualification verification reports
Reports

Partnering with Infinita Lab for Optimal Results

Infinita Lab addresses the most frustrating pain points in the BS EN ISO 5173 testing process: complexity, coordination, and confidentiality. Our platform is built for secure, simplified support, allowing engineering and R&D teams to focus on what matters most: innovation. From kickoff to final report, we orchestrate every detail—fast, seamlessly, and behind the scenes.

Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you. Request a Quote

Frequently Asked Questions

BS EN ISO 5173 specifies a mechanical test that assesses how ductile and sound the weld joint is in the metal. The test works by bending the weld sample over a mandrel and checking if any signs of defects appear in the weld metal and the heat-affected zone.

The purpose of the test is to measure the soundness and ductility of the weld joints and detect defects such as lack of fusion, slag inclusions, and porosity in the welds that could affect their performance in service.

Normally, the bend tests involve bending the sample to an angle of about 180 degrees, but this could vary depending on the welding procedure specification and the material thickness.

After that, the external surface is visually inspected for any cracks or openings. If the number and size of the cracks remain within the limit set by the relevant welding standard, the weld is acceptable.

Yes. This test falls under the destructive tests since the welded specimen is deformed when it is subjected to bending.