BV DH40 Shipbuilding Steel Plate

Technical Reviewer: Jack | SHH STEEL Material Solutions Department · Updated: 2026-10-27

Bureau Veritas lists BV DH40 (BV DH40) as a higher-strength hull grade with Charpy fixed at −20 °C under NR216 / IACS UR W11. Strength level 40 means minimum yield 390 N/mm², tensile 510–650 N/mm² and elongation 20 % min. (A5). The letter DH fixes Charpy V-notch testing at −20 °C. In commercial enquiries it is called BV DH40 or BV DH40 shipbuilding steel plate.

Equivalent grades: BV DH40 ≈ ASTM A131 Grade DH40 ≈ ABS DH40 ≈ DNV NV D40 ≈ LR DH40 ≈ CCS D40 / DH40 ≈ NK KD40 ≈ KR RD40 ≈ RINA DH40 ≈ GB 712 Grade DH40 (all class-approved, stamped by the issuing society).

BV DH40 is selected when scantlings need the higher yield of the 40 band and the material class assigns −20 °C toughness. Ordinary-strength BV Grade A–E stay at 235 N/mm² yield and cannot replace DH40 without a drawing change. Within the 40 band, letter choice is toughness: AH 0 °C → DH −20 °C → EH −40 °C → FH −60 °C; within the DH letter, strength steps 32 → 36 → 40 raise yield from 315 to 355 to 390 N/mm².

Plates that pass mill tests under Bureau Veritas survey are die-stamped or stencilled BV DH40 or BV DH40 (plus Z or U where through-thickness or ultrasonic requirements apply) and are supplied with a mill certificate the BV Surveyor endorses. SHH STEEL supplies BV DH40 from Chinese mills that hold Bureau Veritas works approval for the grade, from stock in common sizes or from a mill rolling cycle, with BV survey arranged at the mill.

Size range. Common market thicknesses for DH40 are about 6–80 mm (heavier plates available as per mill approval), widths 1500–3500 mm. Exact maximum thickness for a given delivery condition is as per standard and mill certificate / BV works approval. Ask for confirmation above 100 mm.

Product (check) analysis column: BV NR216 specify heat (ladle) limits; no numeric product-analysis tolerance is tabulated in the rule text reviewed, so product (check) limits are agreed on the order or taken from the approved mill specification and certificate.

Source: IACS UR W11 higher-strength chemistry tables (ladle samples) — the chemistry Bureau Veritas applies to BV DH40 via NR216. AH/DH/EH share one chemistry column; FH is tighter on C, P, S and adds N control with higher Ni allowance. Toughness is differentiated by impact temperature and supply routes, not by separate C/Mn caps within AH/DH/EH. Product (check) analysis numeric tolerances are not tabulated in UR W11; when required, agree tolerances at enquiry. TMCP steels must also meet the applicable Ceq / Pcm limits on the mill approval — ask for Ceq on the certificate.

Alternative flat-specimen elongations by thickness (indicative UR W11 / industry table for strength 40):

Same tensile band applies to AH/DH/EH/FH 40; only impact temperature and chemistry group (FH vs AH/DH/EH) change across the letter.

Source: IACS UR W11 impact table for higher-strength Grade DH40 (full-size; either direction acceptable unless specified). Energies rise with thickness — a 60 mm plate must meet higher values than a 20 mm plate at the same −20 °C. Condition of supply and impact lot size depend on grain-refining practice and thickness (AR/CR/N/TM/QT as permitted). For TMCP DH40, respect Ceq caps ≈ 0.40 % (t≤50) / 0.42 % (50

Bureau Veritas applies IACS UR W13 thickness tolerances unless the PO states otherwise (often 0.3 mm minus class — confirm on PO; see UNCERTAIN). Plus/flatness/width/length per agreed standard (ASTM A6 or EN 10029). Surface quality per EN 10163 or equivalent accepted by BV; state primer/surface class on receipt if needed.

Quantities are approximate and change daily (indicative — confirm before booking); all stock plates carry BV DH40 marking and Bureau Veritas–endorsed mill certificates when sold as BV class plate. Sizes outside the table (for example 3000 mm width, 60–100 mm thickness, or fixed lengths for a cutting plan) are produced in the next mill rolling cycle, typically 3–6 weeks including BV survey. Send your size list and we will reply with what is in stock and what must be rolled.

Packing. Plates are bundled by size with steel strapping, marked with heat number, grade and BV stamp, and shipped in containers (up to about 11.8 m) or break bulk for longer plates.

These are comparisons, not substitutions. Multi-class stamps (BV + ABS / DNV / LR) require joint survey before rolling.

Pick DH40 when the drawing specifies higher-strength grade DH40 (or the society equivalent). Do not substitute ordinary Grade A/B unless the designer recalculates scantlings — yield differs (390 vs 235). Within the 40 band, letter choice is toughness: AH 0 °C → DH −20 °C → EH −40 °C → FH −60 °C. Within the DH letter, strength steps 32 → 36 → 40 raise yield from 315 to 355 to 390 N/mm².

For yields above 390 N/mm² Bureau Veritas / IACS move to extra-high strength (UR W16 naming — BV uses A420…F690 without H, not AH420).

When BV BV DH40 is the right choice: typical uses are higher-strength members that the material class table assigns to −20 °C, such as thicker deck and bottom strakes, sheer strakes and hatch coamings. The Charpy temperature (−20 °C) is fixed by the letter, and the strength by the number (ReH 390 N/mm²). Pick the strength from the scantling calculation and the letter from the material class and design temperature on the approved drawing.

Typical uses: higher-strength members that the material class table assigns to −20 °C, such as thicker deck and bottom strakes, sheer strakes and hatch coamings; weight-saving vs ordinary-strength plate in large tankers, bulkers and container ships. See offshore platform steel plates when primary offshore grades apply.

Welding: higher-strength hull steels need approved higher-strength consumables matched to −20 °C weld-metal toughness; preheat and heat input follow the approved WPS and often track Ceq/Pcm from the mill certificate. TMCP DH40 must respect the Ceq caps noted above. Cutting by oxy-fuel/plasma/laser is routine; thick FH plate may need hydrogen control — follow mill recommendations.

Processing notes for BV DH40: cold forming is routine within normal shipyard radii. Line heating and fairing of TMCP plate should stay within the temperature limits recommended by the mill, because overheating can reduce the strength gained in controlled rolling. Check the delivery condition on the certificate before planning hot forming.

Every plate is tested and marked at the mill under Bureau Veritas survey; the mill certificate lists heat number, ladle chemistry, Ceq where applicable, tensile results (ReH ≥ 390 N/mm², Rm 510–650 N/mm², A ≥ 20 %), Charpy at −20 °C, delivery condition and plate numbers, endorsed by the Surveyor. Optional EN 10204 3.2, UT (U), Z-direction, multi-class with ABS/DNV/LR.

On receipt: verify BV DH40 stamp, −20 °C impact data, energies for the delivered thickness band, thickness within UR W13 / PO tolerance, BV endorsement present.

Charpy acceptance for BV DH40 by thickness (IACS UR W11; actual results as per standard and mill certificate):

If UT or 3.2 was ordered, check the UT report and inspector’s plate list as well.

• Ordering “BV 40” without the letter (DH/…) — toughness class missing
• Accepting ordinary-strength Grade A/B certificates for a DH40 PO
• Ignoring TMCP Ceq caps on TM plate
• Substituting a different letter (e.g. AH for DH) without drawing approval
• Coil-cut plate without coil approval
• Missing BV endorsement on the MTC
• Writing DNV NV D40 or LR/DH40 on a BV-class PO without arranging that society’s survey

Write grade, delivery condition, impact temperature and certificate type into the PO.

Specify BV DH40 (BV DH40), delivery condition (AR/CR/N/TM/QT as applicable), thickness × width × length × qty, Z/U, multi-class, certificate type, port. Send to SHH STEEL.

Sample PO line: “Steel plate to Bureau Veritas NR216 Materials, Grade DH40 (BV DH40), delivery condition [AR/CR/N/TM/QT], 20 × 2500 × 12000 mm, 30 pcs, marked BV DH40 / BV DH40, certificate endorsed by BV Surveyor, EN 10204 3.2 [if required], UT [if required], CIF [port].”

BV DH40 / BV DH40 is higher-strength hull steel under Bureau Veritas NR216 Materials rules and IACS UR W11: yield 390 N/mm², tensile 510–650 N/mm², Charpy at −20 °C, marking BV DH40. Lock on the order: delivery condition, impact lot size, TMCP Ceq if TM, product analysis if needed, multi-class and 3.2.

SHH STEEL supplies BV DH40 plate rolled by Chinese mills that hold Bureau Veritas works approval for the grade, so every plate carries the BV DH40 stamp and a Surveyor-endorsed certificate traceable to its heat. Common thicknesses are available from stock; other sizes are scheduled into the mill rolling cycle with BV survey arranged at the mill. On request we add EN 10204 3.2 certificates with third-party witness (TÜV, SGS, LR or another agency) and joint certification with ABS, DNV, LR, CCS, NK, KR or RINA.

We accept T/T or L/C payment, with inspection before the balance is paid. Small quantities in several sizes, or BV DH40 mixed with BV Grade A/B/D/E or other AH–FH sizes, can be combined in one container. A dedicated coordinator sends production and shipping updates with photos, and our own workshop cuts to size, bevels, drills and machines plates before shipment so they arrive ready for fabrication.

Request a quotation: send SHH STEEL the grade (BV DH40 / BV DH40), thickness, width, length, quantity per size and destination port, plus any multi-class, Z/U or 3.2 certificate requirement. We reply with price, available stock and lead time.