ABS DH40 Shipbuilding Steel Plate Supplier

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

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

ABS DH40 is a higher-strength hull structural steel under ABS Rules Part 2, Chapter 1, Section 3 (2-1-3). It belongs to the D-class (−20 °C) toughness group at strength level 40: minimum yield 390 N/mm², tensile 510–650 N/mm², elongation 20 % min. Plates are die-stamped AB/DH40 after ABS survey. DH40 pairs 390 N/mm² yield with −20 °C toughness — the usual higher-strength match to ordinary Grade D strakes.

Thickness coverage for plates: AH/DH/EH 32/36 and AH/DH/EH 40 / FH 32/36/40 are listed up to 150 mm (2-1-3/1). Ordinary-strength ABS Grade A / ABS B / ABS D / ABS E stay at 235 N/mm² yield; DH40 is selected when scantlings need the higher yield of the 40 band.

SHH STEEL supplies ABS DH40 from ABS-approved Chinese mills, stock or mill roll, with optional multi-class and EN 10204 3.2. Related pages: ABS DH32 / ABS DH36; same strength other toughness: ABS AH40 / ABS EH40 / ABS FH40.

Buyer note for DH40: DH grades are the higher-strength counterpart to ordinary Grade D: same −20 °C idea, but yield 390 N/mm². Normalized/TM/CR DH plate may carry the N mark (AB/DH40N). Live reference for ordinary strength: ABS Grade A.

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 / ABS works approval.

Product (check) analysis column = heat (ladle) limit adjusted by ASTM A6/A6M-19 Table A “Permitted Variations in Product Analysis”, as required by ABS Rules Part 2, 2-1-2/5.3 (maximum + “over”, minimum − “under”; row chosen by the specified upper limit); arithmetic shown in brackets.

Source: ABS 2-1-3/7.3 Table 1. Heat (ladle) analysis must meet the table. Product (check) analysis, when required, follows ABS 2-1-2/5.3 → ASTM A6 (or other national) tolerances — ABS itself publishes no numeric product limits. AH/DH/EH share one chemistry column; toughness is differentiated by impact temperature and Table 5 supply routes, not by C/Mn caps. TMCP steels must also meet Table 6 Ceq. Ask for product analysis and Ceq/Pcm on the certificate at enquiry.

Source: 2-1-3/7.3 Table 2. Alternative B specimen elongations (Table 3) for XH40:

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: 2-1-3/7.3 Table 4 (full-size; either direction acceptable). Condition of supply and impact lot size follow Table 5 and depend on grain-refining element (Nb, V, Al, Al+Ti) and thickness. In brief for plates: AH grades allow “any” condition in thinner bands with 50 t lots; DH often N/TM/CR; EH/FH plate routes are predominantly N/TM with each-piece (P) impact in many cells. Exact route for your thickness is as per standard and mill certificate — state the required delivery condition on the PO.

TMCP DH40: carbon equivalent caps 0.40 % (t ≤ 50) and 0.42 % (50 < t ≤ 100) per Table 6; over 100 mm Ceq agreed with ABS at mill qualification.

Minus tolerance 0.3 mm (2-1-1/15.3.2). Plus/flatness/width/length per ASTM A6 or as agreed. Surface repair per 2-1-1/3; state primer/surface class in the order if needed.

Quantities are approximate and change daily; all stock plates carry AB/DH40 marking and ABS-endorsed mill certificates. Sizes outside the table are produced in the next mill rolling cycle, typically 3–6 weeks including ABS survey (as per standard and mill certificate for exact lead time). Send your size list and we will reply with stock vs roll.

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

Comparisons, not substitutions. Multi-class stamps require joint survey before rolling.

Pick DH40 when the drawing specifies higher-strength grade DH40 (or the society equivalent). Do not substitute ordinary Grade D 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 ABS moves to Extra High Strength (2-1-8, AQ43/DQ47…), commercially often titled AH42/AH46 — see ABS AH42 and siblings.

When ABS 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. Swapping to a different letter or strength needs class approval of the drawing change, not just a new purchase order.

Typical uses: higher-strength members needing −20 °C; ice-class and cold-route primary structure where DH40 is drawn. See offshore platform steel plates when primary offshore grades apply.

Welding: higher-strength hull steels need approved higher-strength consumables matched to required weld-metal toughness; preheat and heat input follow the approved WPS and often track Ceq/Pcm from the mill certificate (as per standard and mill certificate). TMCP DH40 must respect Table 6 Ceq caps. Cutting by oxy-fuel/plasma/laser is routine; thick QT/FH plate may need hydrogen control — follow mill recommendations.

Within the DH letter, moving 40 → other strengths (ABS DH32, ABS DH36) changes yield/tensile/elongation and Table 4 energies, not the Charpy temperature (−20 °C). Pick strength from the scantling; pick letter from the design temperature.

Processing notes for ABS DH40: cold forming of DH40 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.

ABS survey at the mill; certificate includes ladle chemistry, Ceq where applicable, tensile, Charpy at −20 °C, delivery condition and plate identity. Optional EN 10204 3.2, UT (U), Z-direction, multi-class. On receipt: verify AB/DH40 stamp, −20 °C impact data, energies ≥ Table 4, thickness ≥ nominal − 0.3 mm.

Charpy acceptance for ABS DH40 by thickness (from 2-1-3; actual results as per standard and mill certificate):

On receipt, check that the test temperature on the certificate is −20 °C and that the energy matches the band for the delivered thickness, not the thinnest band. Also check that the plate number on the stamp matches the certificate line, and that the ABS Surveyor endorsement is present. If UT was ordered (e.g. EN 10160 or ASTM A578 level), check the UT report as well. If the PO asked for 3.2, the inspector’s report must name the witnessed tests and plate numbers.

• Ordering “ABS 40” without the letter (AH/DH/EH/FH) — toughness class missing
• Accepting ordinary-strength Grade D certificates for a DH40 PO
• Ignoring TMCP Ceq caps (0.40/0.42) on TM plate
• FH chemistry (tighter P/S, N) not checked when the PO says FH
• Coil-cut plate without coil approval
• Missing ABS endorsement on the MTC
• Stock vs mill roll for ABS DH40?: Common 8–25 mm DH40 is often available from China stock with DH40 marking; thicker or QT/FH routes are usually mill-roll with ABS survey (about 3–6 weeks as a commercial estimate — confirm per order).

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

Specify ABS DH40 (2-1-3), 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 ABS Rules Part 2 2-1-3, Grade DH40, delivery condition [AR/CR/N/TM/QT], 20 × 2500 × 12000 mm, 30 pcs, marked AB/DH40, certificate endorsed by ABS Surveyor, EN 10204 3.2 [if required], UT [if required], CIF [port].” Each bracketed item changes price, lead time and which mills can supply, so fix them at enquiry stage.

ABS DH40 is higher-strength hull steel: yield 390 N/mm², tensile 510–650 N/mm², Charpy at −20 °C, marking AB/DH40. Lock on the order: delivery condition per Table 5, impact lot size, TMCP Ceq if TM, product analysis if needed, multi-class and 3.2.

SHH STEEL supplies DH40 from ABS-approved mills with Surveyor-endorsed certificates, stock or roll, optional 3.2 and multi-class.

T/T or L/C with inspection before balance; mixed containers; photo follow-up; in-house cutting/bevelling/drilling/machining.

Request a quotation: send SHH STEEL ABS DH40, sizes, qty, port and any multi-class/Z/U/3.2 needs.