ISO/TR 15608 Material Groups: Classification and Qualification Coverage
Introduction
ISO/TR 15608 establishes a grouping system for metallic materials for welding qualification purposes. It is the basis of ISO 15614-1 (welding procedure qualification) and ISO 9606-1 (welder qualification). Understanding the groups is essential to determine the coverage of an existing qualification and whether new qualifications are needed for a given material.
---
Steel Groups (Groups 1 to 11)
Group 1 — Structural steels (low alloy, Re ≤ 460 MPa)
| Sub-group | Description | Examples |
|---|---|---|
| 1.1 | Re ≤ 275 MPa | S235, S275 |
| 1.2 | 275 < Re ≤ 360 MPa | S355 |
| 1.3 | Re > 360 MPa (up to 460) | S420, S460 |
| 1.4 | With impact guarantee at T < −20°C | S355N, S420M |
Group 2 — Thermomechanically rolled fine-grain steels (Re > 360 MPa)
| Sub-group | Description | Examples |
|---|---|---|
| 2.1 | Re > 360 MPa | S460M, S500M |
| 2.2 | Re > 460 MPa | S550M, S620M |
Group 3 — Quenched and tempered high-strength steels
| Sub-group | Description | Examples |
|---|---|---|
| 3.1 | Re ≤ 690 MPa | S690QL |
| 3.2 | Re > 690 MPa | S890QL, S960QL |
Group 8 — Austenitic stainless steels
| Sub-group | Description | Examples |
|---|---|---|
| 8.1 | Cr-Ni (no Mo) | 304, 304L |
| 8.2 | Cr-Ni-Mo | 316L, 316Ti |
Group 10 — Ferritic, martensitic and duplex stainless steels
| Sub-group | Type | Examples |
|---|---|---|
| 10.1 | Ferritic | 430, 409 |
| 10.2 | Martensitic | 410, 420 |
| 10.3 | Duplex | 2205, 2304, 2507 |
---
Other Materials
| Groups | Material |
|---|---|
| 21–26 | Aluminium and aluminium alloys |
| 31–38 | Copper and copper alloys |
| 41–48 | Nickel and nickel alloys |
---
Qualification Coverage (ISO 9606-1)
| Qualified group | Also covers |
|---|---|
| Group 1 | Group 1 |
| Group 2 | Groups 1 and 2 |
| Group 3 | Groups 1, 2 and 3 |
| Group 8 | Group 8 only |
| Group 10.3 (duplex) | Group 10.3 |
Note: Full coverage rules are defined in ISO 9606-1, Table 4.
---
Procedure Qualification Coverage (ISO 15614-1)
A WPQR qualification on a material from a given group/sub-group covers:
- The same group/sub-group
- Lower-numbered groups within the same family (subject to conditions)
- See ISO 15614-1, Table 7 for full coverage
---
📘 Read the full article with more details at WeldFC Academy →