Structured specification reference
| Parameter | Reference / acceptance condition |
|---|---|
| Reference basis | IACS UR W11 Rev.9; reference, not ASTM acceptance |
| Product scope | Plate / wide flat ≤100 mm; thicker material requires separate review |
| Minimum yield strength | 235 MPa |
| Tensile strength | 400–520 MPa |
| Minimum elongation A5 | 22%; proportional specimen; other gauge lengths differ |
| Impact category | Grade A: thickness/route-dependent provisions; no universal no-test claim |
| Certification | Requested society and actual plate certificate must be confirmed |
| Thickness tolerance | Order-specific; see dimensional guide and applicable class rule |
| Chemistry basis | W11 Rev.9 Table 1; plate ladle analysis; route exceptions apply |
| C max | 0.21 mass % |
| Si max | 0.50 mass % |
| P max | 0.035 mass % |
| S max | 0.035 mass % |
Selection and application
Normal-strength hull plate for locations permitted by the approved hull material plan. Check thickness-dependent impact-testing provisions instead of describing Grade A as universally untested. The approved structural drawing and material schedule determine where the grade may be used; this page does not approve a specific vessel detail.
Read the parameter table correctly
The parameter table gives a W11 reference, with the stated product and test conditions. They are not measured results for a stocked heat. ASTM A131/A131M and individual class rules must be checked separately; do not mix tensile limits or chemistry footnotes from different editions.
Delivery and fabrication
Confirm the permitted rolling or heat-treatment route for the ordered thickness and mill approval. Request welding, forming and heating recommendations for the actual supplied condition. Keep heat and plate identity when subdividing, and agree any transfer of class marks before cutting.
Certification and order specification
State the required society, dimensions, plate count or tonnes, destination, standard edition, delivery condition and supplementary tests. ABS, CCS, DNV, LR, BV and RINA are selectable enquiry requirements; this site does not assert that every plate holds all approvals.
Edition control
IACS has published W11 Rev.10 with implementation triggers dated 1 January 2027. Establish the applicable project and certification dates before changing the reference edition. The uploaded handbook’s GB 712—2011 tables are historical and must not silently replace the contract rule.
Order parameters
- Thickness / size scope
- Confirm grade/thickness/mill approval combination
- Delivery condition
- Subject to grade, thickness and approved mill route
- Class society requested
- ABS, CCS, DNV, LR, BV, RINA
Society names are enquiry options. Approval and certificate scope must be confirmed for the actual material.
Frequently asked questions
What is required to order A plate?
Specify grade, product standard and edition, class society, thickness × width × length, quantity, delivery condition and supplementary testing.
Is A automatically approved by every class society?
No. Approval scope and the actual plate certificate must match the named project society and ordered product.
Sources and reference scope
- IACS UR W11 Rev.9 (May 2017) — Sections 1–8; chemistry tables 1–2 and mechanical tables 6–7
Reference values are conditioned on grade, thickness, specimen and project rule. Not ASTM A131 acceptance data. - IACS UR W11 Rev.10 (September 2025) — Scope and implementation note
Implementation note refers to 1 January 2027 triggers. Do not automatically apply to an October 2026 order. - 中外钢铁牌号速查手册（第4版） — PDF pp. 275–277; printed pp. 264–266, tables 5-4/5-5
GB 712—2011 chemistry is historical reference, not a current contract standard. Table footnotes inspected. - 钢材产品简介 — Slides 3, 5–6, 15–19
Product forms, units and grade vocabulary; not proof of current stock or class certification.