Shipbuilding steel grades explained
Grade A is chemically close to S235JR and AH36 to S355J2, but the difference is the classification-society survey: the heat, plate and test pieces are witnessed and stamped by LR, BV, DNV, ABS, RINA or Türk Loydu, and the certificate names the society. Uncertified S235/S355 cannot be used for class-surveyed hulls.
| Grade | Yield min (MPa) | Tensile (MPa) | Impact (27 J normal / 34 J high) | Delivery | Use |
|---|---|---|---|---|---|
| A | 235 | 400–520 | +20 °C (t > 50 mm) | As rolled | Hull plating, decks, bulkheads (most stock) |
| B | 235 | 400–520 | 0 °C | As rolled | Thicker hull plating |
| D | 235 | 400–520 | −20 °C | Normalized / TM | Cold regions, critical members |
| E | 235 | 400–520 | −40 °C | Normalized | Ice class, sheer strake |
| AH32 | 315 | 440–570 | 0 °C | As rolled / TM | High-strength decks |
| AH36 | 355 | 490–630 | 0 °C | As rolled / TM | High-strength hull, decks (stock) |
| DH36 | 355 | 490–630 | −20 °C | Normalized / TM | Critical high-strength members |
| EH36 | 355 | 490–630 | −40 °C | Normalized / TM | Ice class, offshore |
Letters A/B/D/E = toughness temperature; H32/H36 = yield 315/355 MPa. Every plate carries the class stamp and heat number.
Grade pages
Every hull grade we supply has its own page with chemistry, mechanical properties, the society rules that require it, sizes and weights: ordinary-strength Grade A ship plate and Grade B ship plate, and the 355 MPa higher-strength series AH36 (0 °C), DH36 (−20 °C) and EH36 (−40 °C, offshore).
Sizes and stock
| Grade | Thickness | Width | Length | Availability |
|---|---|---|---|---|
| Grade A | 5–50 mm | 1 500 / 2 000 / 2 500 | 6 000 / 8 000 / 12 000 | 6–25 mm stock (BV / LR / TL) |
| Grade B / D | 8–60 mm | 2 000 / 2 500 / 3 000 | 6 000–12 000 | Order 4–6 weeks |
| Grade E | 10–80 mm | 2 000–3 000 | 6 000–12 000 | Order 6–8 weeks |
| AH36 | 6–50 mm | 2 000 / 2 500 | 6 000–12 000 | 8–20 mm stock (BV / DNV) |
| DH36 / EH36 | 8–80 mm | 2 000–3 000 | 6 000–12 000 | Order 4–8 weeks |
Which classification society?
Tell us which society surveys the vessel; plate is ordered or stocked under that society's certificate (dual-certified plates BV/LR or DNV/ABS are common). Türk Loydu (TL) covers Turkish-flag and many regional vessels; LR and BV are the most requested for Gulf and African fleets; DNV and ABS for offshore. Re-certification of a plate from one society to another is possible only with a new survey of the heat.
Cutting, bevelling and shop primer
Plasma to 80 mm and oxy-fuel beyond, to the yard's nesting files; bevels for hull welding (30° K/V); shot-blast to Sa 2½ and class-approved zinc-silicate shop primer 15–20 µm (weld-through); plate marking with heat and class number is preserved or transferred under survey. Profiles (bulb flats, angles) and pipe to class on request.
Applications
- New-build hulls, decks, bulkheads, double bottoms (Grade A / AH36)
- Repair and dry-dock plate for tankers, bulkers, ferries, tugs
- Barges, pontoons, floating docks, fish-farm structures
- Offshore modules and jackets (DH36 / EH36 with UT and Z35)
- Dredgers and workboats; wear plate for hoppers on request
Shipbuilding plate price per ton
Class-certified plate is priced per lot above structural S235/S355 — Grade A typically +5–10%, AH36 +8–15%, D/E and DH/EH grades +15–30% (normalizing and low-temperature testing), plus the survey fee. Ask for the current USD/MT for grade, society, thickness and quantity.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
Plates strapped on bearers, primed plates with corner protection; 6 m plates in 40' HC, 8–12 m by flat-rack or breakbulk from Derince. HS code 7208.51 / 7208.52 with class certificate.
| Term | Detail |
|---|---|
| MOQ | 10 t per grade; class survey per lot |
| Incoterms | FOB Derince / Istanbul · CIF / CFR Gulf, Red Sea, Africa · DAP Balkans, Caucasus |
| Lead time | Grade A / AH36 stock 5–10 working days; other grades 4–8 weeks |
| Packing | Plates strapped on bearers, corner protection for primed plates |
| Container / truck | 40' HC to 6 m / 24 t · flat-rack to 12 m · breakbulk |
| Documents | Class certificate, EN 10204 3.2, UT, certificate of origin |
| Payment | 30% advance, balance against B/L copy; L/C at sight |
Certificates
Class certificate (LR / BV / DNV / ABS / RINA / TL) per heat and plate, EN 10204 3.2 witnessed, UT and Z-quality on request, certificate of origin.
How to order
Send grade, society, thickness × width × length or nesting, quantity, primer requirement and port. Reply within one working day with price per ton, certificate availability and lead time.
Standards
- IACS UR W11 (normal and higher strength hull structural steels)
- Class rules: LR, BV, DNV, ABS, RINA, Türk Loydu
- ASTM A131 / A131M
- EN 10025-2 S235JR / S355J2 (equivalent chemistry, not class-certified)
- EN 10029 tolerances
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: S235JR (Grade A comparison) · S355J2 (AH36 comparison) · A36
Frequently asked questions
What is Grade A steel?
Normal-strength hull structural steel (235 MPa yield, 400–520 MPa tensile) certified by a classification society — the most used plate in shipbuilding, chemically close to S235JR but surveyed and stamped.
What is the difference between AH36 and DH36?
Same 355 MPa yield; DH36 is impact-tested at −20 °C (AH36 at 0 °C) and usually normalized or TM-rolled, for critical members and colder waters.
Can I use S235JR for a boat instead of Grade A?
For non-classed small craft yes; for any vessel under class survey the plate must be class-certified (Grade A), otherwise the surveyor rejects it.
Which classification societies can you supply under?
Lloyd's Register, Bureau Veritas, DNV, ABS, RINA and Türk Loydu; dual-certified plates BV/LR and DNV/ABS are common in stock.
Do you supply plate blasted and primed?
Yes — Sa 2½ and class-approved zinc-silicate shop primer 15–20 µm, with class markings preserved.
How much does shipbuilding plate cost?
Grade A about 5–10% above structural S235 plate, AH36 8–15% above S355, D/E and DH/EH grades more; plus the class survey fee per lot. Firm price within one working day.