Also in the Knowledge Center
Frequently Asked Questions on Testing Methods
Which testing methods are available for stud welding, and which are relevant for the operator?
Inspection of the weld in stud welding is essential. Unlike other welding processes, all testing methods (except for visual inspection) are destructive. For the operator, only visual inspection and bend testing are generally relevant, and in some cases torque testing as well. Other methods such as X-ray inspection, macro sectioning, tensile testing, and process monitoring are the responsibility of the welding supervisor or external inspection bodies.
What must be considered during visual inspection after each weld?
The operator must carry out a visual inspection after every weld. The weld bead should always be completely closed all around and have a bright, shiny surface. After welding, the stud should measure its nominal length. This simple yet important check provides an initial indication of the weld joint’s quality.
When and how is the bend test performed?
Before starting work (at the beginning of each shift), the operator must weld at least three studs, bend them to 60°, and then visually inspect and properly document the results. The test is passed if no fracture or crack is found in the weld or heat-affected zone. The bend test can be performed using a hammer, a pipe, or a hydraulic press — always observing proper safety precautions.
What is the purpose of X-ray inspection in stud welding?
Radiographic testing is mainly used to detect porosity in the weld joint. Depending on the applicable standard, defects in the stud cross-section may not exceed 5% or 10%. This inspection is carried out by the welding supervisor or external testing bodies and provides insight into the internal quality of the weld.
Technical Resources
Our technical documents provide you with welding parameters, standards overviews and quality guidelines for various materials and industries – as a basis for norm-compliant welding results.
Bolzenschweißen in Übereinstimmung mit den DIN ISO 14555
7.25 MB
Sicheres Bolzenschweißen in der Werkstatt und auf der Baustellen nach internationalen Regelwerken
7.45 MB
Lichtbogenbolzenschweißen - zuverlässig auch bei dünnen beschichteten Blechen?
4.39 MB
Bolzenschweißen im Bauwesen
493.76 KB
Aufgeschweißte Kopfbolzen nach Eurocode 4
46.44 KB
Erweiterte Qualitätssicherung beim Bolzenschweißen mit Hubzündung
59.97 KB
KÖCO Verbundbau
5.19 MB
Glossary
Here you’ll find all the key terms related to quality testing and standards in stud welding. Each term is clearly explained, showing you how to assess and ensure the quality of your weld joints.
Hardness test
The hardness test is used to check the resistance of a stud weld in terms of strength and toughness, and assesses the hardness profile of the weld zones. The calculation of characteristic values (hardness values) enables the assessment of a stud weld for a technically relevant component, which requires official acceptance as part of general quality assurance. During the hardness test, an indenter with a defined dimension and defined load is pushed into the weld zone to be tested. The hardness is determined by measuring the size of the imprint left by the indenter and the associated test force.
Visual inspection
The quality of a stud weld connection can be negatively affected by external influences. An unnoticed draft, moisture, and impurities at the weld point as well as an insufficient power supply all impact the welding process. In addition, careless calibration or parameter configuration errors can have a significant adverse impact on the quality of the stud weld A trained eye and, where necessary, a magnifying glass are all that are needed to detect external defects.
Typical error patterns in stud welds are:
- slanted studs
- blowholes
- penetrations
- pores
Tensile test
The tensile test in line with DIN EN ISO 6892-1 determines the tensile strength and yield strength of a component. Two key pieces of information for assessing quality. The specimen is stressed such that it initially buckles and then breaks. While the result of a tensile test merely provides an indication of the quality of the specimen, it allows indirect conclusions to be drawn as to the behavior of the finished component in its installed state. Consistent sampling allows potential deviations from the defined tolerances to be identified early on.
Didn’t find the right term?
Explore all technical terms in the full glossary:
