Overview
EN ISO 6848:2015 (ISO 6848:2015) specifies requirements for the classification of nonconsumable tungsten electrodes used in inert-gas shielded arc welding (TIG/GTAW), and for plasma welding, cutting and thermal spraying. The standard defines how tungsten electrodes are characterized by chemical composition, how they are marked and sized, and gives informative guidance on conditions of use (Annex A). It is published by CEN as EN ISO 6848:2015 and supersedes the 2004 edition.
Key Topics
- Classification basis: Electrodes are classified by chemical composition (principal oxide additives).
- Symbol system:
- Process symbol: W for gas-shielded tungsten arc processes.
- Chemical symbol: oxide chemical symbols followed by digits indicating the nominal mass percent of oxide × 10; if no additive, symbol P is used.
- Standard classes (examples): WP (pure), WCe20, WLa10, WLa15, WLa20, WTh10, WTh20, WTh30, WZr3, WZr8, and WG for other compositions. Table 1 in the standard lists composition ranges and impurity limits.
- Marking and colour coding: Electrodes ≥50 mm are marked by colour rings (minimum 3 mm wide) or printed classification symbols; packaging must be marked for shorter electrodes. The standard provides specific colour codes per class.
- Chemical analysis and retests: Requirements for chemical testing of specimens; failing tests must be retested twice and both retests must pass.
- Physical requirements: Standard sizes, tolerances, electrode diameters and lengths, shape, straightness, finish, rounding procedures, packaging and labelling rules.
- Normative references: e.g., ISO 80000-1 (quantities and units).
Applications
- Selection and procurement: Choose the correct tungsten electrode chemistry for arc behavior, arc stability and application (TIG, plasma welding/cutting, thermal spray).
- Manufacturing & quality control: Producers use the classification, marking, testing and packaging rules to ensure consistent product identification and conformance.
- Welding procedure specification (WPS): Welding engineers reference electrode class and marking when preparing procedure documents and personnel training.
- Inspection & traceability: QA/QC teams use marking and labelling rules to trace electrode batches and confirm composition during audits.
Who should use this standard
- Welding engineers and technologists, electrode manufacturers, QA/QC personnel, procurement specialists, standards bodies, and training organizations involved in TIG/GTAW, plasma processes or thermal spraying.
Related standards
Keywords: tungsten electrodes, nonconsumable tungsten electrodes, ISO 6848:2015, EN ISO 6848, TIG, plasma welding, electrode classification, electrode marking, welding consumables.
