Material decisions · AWS D1.1 Clause 5
Base-metal guides for AWS D1.1 WPS decisions
A material entry is one input to a WPS decision. Start with the exact ASTM specification and grade, then check its Table 5.6 strength group, the separate Table 5.11 preheat category, and every remaining Clause 5 condition.
Choose the material decision
| Material | Decision this guide answers | Open guide |
|---|---|---|
| ASTM A36 | When does the Table 5.6 Group I thickness limit matter, and when does Group II apply? | A36 material groups and thickness |
| ASTM A572 Grade 50 | How does Grade 50 differ from A572 Grade 60/65 in filler grouping and preheat category? | A572 Grade 50 vs higher grades |
| ASTM A992 | What does the Table 5.6 Group II listing establish, and what remains to be checked? | A992 and Group II |
| ASTM A500 Grade B/C HSS | How do the material-group and process-based preheat entries relate to a real tubular joint? | A500 HSS and tubular connection decisions |
| ASTM A588 | Which plate and shape products are listed in Group II, and when does weathering filler matching apply? | A588 product form and weathering filler |
| Dissimilar base metals | How should two listed materials in different Table 5.6 groups be handled for filler matching? | Dissimilar-material filler matching |
| Unlisted or unidentified steel | What records and qualification path are needed when a member cannot be mapped to Table 5.6? | Unlisted-steel evidence path |
Continue with the linked checks
Use tools to inspect a known branch or value, then review the complete project conditions. A tool result is not a WPS approval or a substitute for the governing code and contract.
What a grade lookup cannot decide
Clause 5 eligibility depends on the complete applicable procedure: both base metals and their combination; process and sequence; filler classification; joint detail and backing; position; member thickness; gas or flux where applicable; preheat and interpass control; and project requirements. Verify material identity against the actual material documentation. A trade name or strength value is not a substitute for the listed specification and grade.
For projects relying on qualification, an existing PQR must be checked against its real records and the applicable qualification provisions. A base-metal group is not a PQR coverage result.
Code references
The material-group decisions summarized here are from AWS D1.1/D1.1M:2025 Table 5.6. Preheat categories are separately listed in Table 5.11. Filler matching is addressed in Table 5.7, and the applicable Clause 5 requirements extend beyond material listing. See the edition and errata basis for scope.