Grade D (ship)
Data under reviewGrade D extends ordinary-strength hull steel to −20 °C impact service. It is the 235 MPa grade chosen for hulls that trade in cold waters, and a common stepping stone before moving a design up to the DH36/DH40 higher-tensile grades.
Chemical composition
| Element | Content (%) |
|---|---|
| C | ≤0.21 |
| Si | 0.10–0.35 |
| Mn | 0.70–1.20 |
| P | ≤0.035 |
| S | ≤0.035 |
| Note | Al-treated fine-grain practice; chemistry per class rules (IACS UR W11) |
Weight percent, per the governing standard ranges. Actual values per heat are on the mill certificate.
Properties
| Yield strength | ≥235 MPa |
| Tensile strength | 400–520 MPa |
| Impact | −20 °C, ≥27 J longitudinal (≤50 mm) |
| Density | 7.85 g/cm³ |
Heat treatment
Supplied as-rolled or normalized under class survey; aluminium grain-refining is part of the D-grade practice.
Equivalent grades
| Standard | Designation |
|---|---|
| aisi | A131 D |
| jis | KD (near) |
| gb | D (GB/T 712) |
Compare side by side: Grade D (ship) vs Grade B (ship) · Grade D (ship) vs Grade E (ship)
Equivalents overlap in chemistry and use but are not always identical — see our equivalents guide before substituting in certified designs.
Applications & Processing
Applications: Cold-service hulls, fishing vessels, ferries and workboats in northern trades.
Processing: Fine-grain (Al-treated) supply is standard; welding practice follows the vessel’s class rules.
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Ask for a quotationVisit NasteelSource: Classification-society rules (IACS UR W11) published ranges · Last updated 2026-11-03. Data is indicative — verify critical values against the governing standard and mill certificate before use.