Overview
AH36, DH36 and EH36 belong to a 36-strength hull-steel group but differ in toughness designation and approved condition context. Their selection must be tied to the hull member, design temperature, thickness, delivery condition and class approval.
Designation and acceptance
IACS Unified Requirements are minimum classification-society requirements. Grade notation, thickness, delivery condition, test temperature, plate approval and the ship’s class rules must be read together; notation alone does not create an interchangeable material approval.
Members and selection
| Designation | Selection context |
|---|---|
| AH36 | 36-strength group notation selected only where the approved material schedule permits its toughness and condition. |
| DH36 | 36-strength group notation with distinct toughness/test context; check the member rule and thickness. |
| EH36 | 36-strength group notation for conditions requiring the specified toughness class; do not infer interchangeability from yield group alone. |
Comparison framework
| Criterion | Decision context |
|---|---|
| Selection basis | The 36-strength group does not remove the need to order the exact toughness designation and class-approved delivery condition. |
Performance
- Toughness class, thickness, delivery condition and approved testing must match the approved hull-member rule. Do not rank letter suffixes as a universal good-better-best scale.
Orderable product scope
- Shipbuilding plate, wide flat and sections must be quoted with class approval, grade notation, thickness, delivery condition, inspection and material certificates.
Processing
- Control welding procedure qualification, heat input, consumables, repair, NDT timing and identification through cutting and assembly in accordance with the approved shipyard and class requirements.
Applications
- Hull structural members and marine structures where the design, classification and fabrication documents approve the ordered steel.
Selection
- Start with the vessel type, hull-member location, design temperature, thickness and class rule, then choose the approved grade and delivery condition. Grade labels must not replace the class-approved material schedule.
Procurement
- State class society, rule edition, approved mill, grade notation, product form, thickness, delivery condition, impact-test requirement, Z-quality if ordered, certificates, marking, quantities, destination and inspection plan.