ABS FH40 Shipbuilding Steel Plate Supplier

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

Equivalent grades: ABS FH40 ≈ ASTM A131 Grade FH40 ≈ DNV NV F40 ≈ LR FH40 ≈ BV FH40 ≈ CCS F40 / FH40 ≈ NK KF40 ≈ KR RF40 ≈ RINA FH40 ≈ GB 712 Grade FH40 (all class-approved, stamped by the issuing society).

ABS FH40 is a higher-strength hull structural steel under ABS Rules Part 2, Chapter 1, Section 3 (2-1-3). It belongs to the F-class (−60 °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/FH40 after ABS survey. FH40 is the −60 °C grade in the 40-strength band. Chemistry is tighter (C 0.16 max., P/S 0.025, Ni up to 0.80 %). See also live BV FH36 and BV FH40 for sister society FH plate.

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; FH40 is selected when scantlings need the higher yield of the 40 band.

SHH STEEL supplies ABS FH40 from ABS-approved Chinese mills, stock or mill roll, with optional multi-class and EN 10204 3.2. Related pages: ABS FH32 / ABS FH36; same strength other toughness: ABS AH40 / ABS DH40 / ABS EH40.

Buyer note for FH40: FH chemistry (C 0.16, P/S 0.025, higher Ni allowance, N limit) is the main ladle-analysis difference versus AH/DH/EH in the same strength band. Live reference for ordinary strength: ABS Grade A.

Size range. Common market thicknesses for FH40 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. FH grades also limit N and tighten C/P/S versus AH/DH/EH. 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 or QT 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 FH40: 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/FH40 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 FH40 when the drawing specifies higher-strength grade FH40 (or the society equivalent). Do not substitute ordinary Grade E 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 FH 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 FH40 is the right choice: typical uses are low-temperature service: Arctic and polar-class hulls, ice belts and offshore units in cold regions where −60 °C toughness is specified. The Charpy temperature (−60 °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: lowest-temperature higher-strength band (−60 °C); polar and special service — confirm mill approval for FH40. 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 FH40 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 FH letter, moving 40 → other strengths (ABS FH32, ABS FH36) changes yield/tensile/elongation and Table 4 energies, not the Charpy temperature (−60 °C). Pick strength from the scantling; pick letter from the design temperature.

Processing notes for ABS FH40: cold forming of FH40 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 −60 °C, delivery condition and plate identity. Optional EN 10204 3.2, UT (U), Z-direction, multi-class. On receipt: verify AB/FH40 stamp, −60 °C impact data, energies ≥ Table 4, thickness ≥ nominal − 0.3 mm.

Charpy acceptance for ABS FH40 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 −60 °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 E certificates for a FH40 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 FH40?: Common 8–25 mm FH40 is often available from China stock with FH40 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 FH40 (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 FH40, delivery condition [AR/CR/N/TM/QT], 20 × 2500 × 12000 mm, 30 pcs, marked AB/FH40, 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 FH40 is higher-strength hull steel: yield 390 N/mm², tensile 510–650 N/mm², Charpy at −60 °C, marking AB/FH40. 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 FH40 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 FH40, sizes, qty, port and any multi-class/Z/U/3.2 needs.