Overview
ISO/TR 25901-4:2016 - Welding and allied processes - Vocabulary - Part 4: Arc welding is an ISO technical report that standardizes terms and definitions applicable to arc welding. It organizes arc-welding vocabulary systematically and helps ensure consistent use of language across specifications, procedures, technical documents and translations. The report does not repeat terms covered in other parts of ISO/TR 25901 or other ISO standards; it focuses specifically on arc welding terminology. All terms are also available on the ISO Online Browsing Platform (OBP): https://www.iso.org/obp/ui/
Key topics
The document defines and groups arc-welding vocabulary in practical categories, including:
- Welding procedures: e.g., pulsed MAG, pulsed MIG, pulsed TIG, arc‑spot, microplasma, narrow-gap welding.
- Welding execution: techniques and parameters such as push/pull technique, weaving (width, amplitude, frequency), travel and electrode angles, wire feed rate, contact electrode.
- Process characteristics: metal transfer modes (globular, spray, short‑circuit/dip), arc voltage, striking voltage, arc length/time, pulse time, duty cycle, arc blow, stand-off, stickout, deposition coefficient and efficiencies.
- Consumables: covered electrodes (acid, basic, cellulosic, rutile), iron‑powder and high‑efficiency electrodes, wire and strip electrodes, flux‑cored/tubular/metal‑cored electrodes, non‑consumable electrodes, stub ends.
- Power-source characteristics: static and dynamic characteristics, drooping and flat (constant‑voltage) characteristics, no‑load (open‑circuit) voltage.
- Equipment terms: contact tips, collets, welding guns/torches and other torch components.
Annex A provides an alphabetical index of English terms with French translations (ISO official language) and German translations (provided by DIN for information). Note: only English, French and Russian are official ISO terms per the report.
Applications and users
ISO/TR 25901-4 is useful for:
- Welding engineers, inspectors and QA professionals who need consistent terminology in specifications, procedure documents and reports.
- Standards writers and technical authors preparing manuals, test methods and procurement documents.
- Training organizations and educators building curricula and teaching materials for arc welding (MIG, MAG, TIG, plasma).
- Translators and multilingual teams working on technical translation and harmonization of welding terminology.
- Manufacturers and procurement teams creating product documentation or purchasing specifications referencing standardized terms.
Using this vocabulary helps reduce ambiguity in contracts, design documents, inspection criteria and international collaboration on welding projects.
Related standards
Keywords: ISO/TR 25901-4:2016, arc welding vocabulary, welding terminology, MIG MIG/MAG TIG, welding standards, welding consumables, welding procedures.