Understanding Welding Consumable Nomenclature is key to choosing the right filler metal, electrode, or wire for a specific welding process, base material, and service condition. Standards such as AWS‑A5, ISO 2560, and EN 499 define naming systems used in processes like SMAW, GMAW, GTAW, FCAW, and SAW. Through careful interpretation, welders and engineers gain insight into tensile strength, coating, position suitability, hydrogen control, and alloy composition—ensuring compliant and high-quality welds.
✅ SMAW Welding Consumable Nomenclature (e.g. E7018)
Per AWS A5.1 classification, SMAW electrodes are designated by “E” followed by four or five digits that encode key performance characteristics as defined below
- E – Electrode
- 70 – Minimum tensile strength: 70 ksi
- 1 – Suitable for all welding positions
- 8 – Indicates low-hydrogen potassium coating with iron powder, suitable for AC or DCEP current
Optional suffixes offer further detail:
- “-1”: improved ductility or toughness requirement
- “H4”: diffusible hydrogen ≤4 ml/100g
- “R”: passed moisture absorption resistance
🔹 Examples:
- E6010 – Cellulose coating; deep penetration; DC+ only
- E7018‑H4R – Low-hydrogen, iron powder coating; multi-position; AC/DC+
GMAW & GTAW Wire Nomenclature (e.g. ER70S‑6)
According to AWS A5.18, solid wire designations are identified via:
- ER – Electrode Rod for GMAW/GTAW
- 70 – Tensile strength: 70 ksi
- S – Solid wire
- 6 – Chemical additives/deoxidizer content, affecting weld cleanliness and arc stability
🔹 Common wire examples:
- ER70S‑2 – Triple deoxidized for welding dirty/rusted surfaces
- ER70S‑6 – Silicon-rich wire; tolerant of mill scale; fluid weld pool
FCAW Wire Nomenclature (e.g. E71T‑1C/MJH8)
Under AWS A5.20, flux-cored wire is designated as:
- E – Electrode
- 71 – Minimum tensile strength: 71 ksi
- T – Tubular flux-cored wire
- 1 – All-position usability
- Suffixes (e.g. C, M, J, H) define shielding gas compatibility, arc characteristics, hydrogen level, and impact toughness
🔹 Example variations:
- E71T‑1C – CO₂-shielded; all-position
- E71T‑1M – Mixed gas (Ar+CO₂); enhanced arc control
- MJH8 – Includes modifiers for toughness, hydrogen, and impact resistance
SAW Consumables Nomenclature (e.g. F7A2‑EM12K)
According to AWS A5 and ISO/EN standards, SAW flux and electrode classifications encode performance metrics:
- F7A2
- F7 – Flux for 70 ksi ultimate tensile strength
- A2 – Minimum impact toughness at –20 °C
- EM12K
- E – Electrode
- M12K – Alloy content (manganese and carbon), K = aluminum-killed steel
These consumables are suited for high-deposition SAW in critical structural and pressure vessel applications.
Global Standards & Specifications
Consumable nomenclature and properties are governed by international standards:
- AWS A5.1–A5.29 series, adopted by ASME SFA designations (§II‑C) for SMAW, GMAW, FCAW, SAW, etc.
- ISO 2560, ISO 14343, ISO 17632 – Global classification of electrodes and wires
- EN 499, EN 12536 – European electrode/wire classification systems
These codes ensure consistent mechanical, chemical, and usability properties worldwide.
Why This Nomenclature Matters
Understanding and applying correct nomenclature helps to:
- Match consumables to base material and application requirements
- Meet welding code compliance, such as ASME, API, ISO
- Avoid defects like hydrogen cracking, porosity, and poor toughness
- Enable proper traceability and inventory control
- Ensure repeatable weld quality regardless of supplier
- For toughness-critical applications, evaluate suffixes like H4, J, etc. in consumable classification.
📊 Quick Reference Summary
| Process | Example Designation | Tensile (ksi) | Pos. | Coating / Gas | Special Notes |
|---|---|---|---|---|---|
| SMAW | E7018‑H4R | 70 | All | Low‑H₂/iron powder | H4R = low hydrogen, moisture resistant |
| GMAW | ER70S‑6 | 70 | — | Solid/Silicon-rich | Good on mill scale |
| FCAW | E71T‑1M | 71 | All | Tubular/Mixed gas | Stable arc, higher deposition |
| SAW | EM12K (with F7A2) | 70 | — | Flux for –20 °C toughness | For heavy section and critical welds |
📢 Final Thoughts
Accurate interpretation of welding consumable nomenclature is essential for weld integrity, safety, and code compliance. Whether you’re a fabricator, inspector, or welding engineer, understanding the meaning behind designations like E7018, ER70S‑6, E71T‑1M, or EM12K empowers you to make proper choices. These naming conventions are standardized via AWS, ISO, and EN systems—eliminating guesswork and reducing risk.