FH40 High Strength Hull Shipbuilding Steel Plate for Marine & Offshore Projects

  IACS Certified 390 MPa Yield Strength Steel with -60°C Impact Toughness  

Overview

The designation FH40 originates from the International Association of Classification Societies (IACS) system. It is not merely a Chinese steel grade, but a universal specification implemented by classification societies and steel mills worldwide. It is an internationally recognized material specification that ensures global consistency in material performance, certification, and acceptance standards for shipbuilding and offshore engineering.

This steel grade is specifically designed for ship hull structures requiring excellent strength performance in extreme cold temperature conditions. Its core performance is characterized by a minimum yield strength of 390 MPa and reliable impact toughness at -60°C, making it an ideal choice for constructing vessels navigating Arctic and Antarctic waters.

Definition and Naming Logic

The designation FH40 originates from the International Association of Classification Societies (IACS) Unified Requirements.

Its logical structure is: 1 letter + 1 letter + 2 digits

First letter (F): Quality grade symbol, representing its impact toughness test temperature at -60°C.
Second letter (H): Strength grade symbol, denoting it as High Strength steel.
Digits (40): Minimum yield strength identifier, in units of 40kgf/mm² (390 MPa).

Code Interpretation

Therefore, when treating FH40 as a code, the correct and complete deciphering is:

"A high-strength shipbuilding structural steel requiring impact testing at -60°C, with a minimum yield strength of 390 MPa."

Value Proposition

Just like the karat standard for gold, the FH40 specification provides the simplest and most reliable common benchmark for complex international procurement. As professional Chinese suppliers, we create our core value by delivering this globally-endorsed quality with optimal cost efficiency and reliable service.

We are a Chinese supplier offering FH40 in spot supply and mill-direct ordering services, with full export service capabilities.

We have served global shipyards and are familiar with classification society inspection processes.

Start Your FH40 Procurement

We provide two procurement options for FH40 steel plates, so you can choose the most cost-effective solution for your project. Backed by competitive prices, strict quality control, and on-time delivery, we make sourcing simple and reliable.

✓ Immediate availability & pricing

✓ Formal quotation in 8 hours

Supply-Available FH40 Ship Plates and Approved Classification Societies 

FH40 steel plates are certified and approved by all major international classification societies, ensuring global acceptance for marine construction projects. The following ranking is in alphabetical order of the classification society abbreviations.

ABS

American Bureau of Shipping

United States

✓ Available
Certified
BV

Bureau Veritas

France

✓ Available
Certified
CCS

China Classification Society

China

✓ Available
Certified
CRS

Croatian Register of Shipping

Croatia

Certified
DNV

Det Norske Veritas  (DNV & GL)

Norway

✓ Available
Certified
IRS

Indian Register of Shipping

India

Certified
KR

Korean Register of Shipping

South Korea

✓ Available
Certified
LR

Lloyd's Register

United Kingdom

✓ Available
Certified
NK

ClassNK

Japan

✓ Available
Certified
PRS

Polish Register of Shipping

Poland

Certified
RINA

Registro Italiano Navale

Italy

✓ Available
Certified
RS

Russian Maritime Register of Shipping

Russia

✓ Available
Certified

Note: In practical applications and certification documents, FH40 is typically prefixed with the specific classification society abbreviation to indicate compliance with that society's specific rules and approval requirements. For example, CCS FH40 (China Classification Society), ABS FH40 (American Bureau of Shipping), BV FH40 (Bureau Veritas), and DNV FH40 (Det Norske Veritas). The exception is the Russian Maritime Register of Shipping (RS), where the steel grade is designated as PC FH40.

Key Advantages of FH40 Steel Grade

Steel Grade
Balanced Strength Performance
Cold Climate Toughness
Marine Durability
Excellent Fabrication Properties
FH40 Marine Steel 390 MPa minimum yield strength provides optimal balance of strength and toughness for the most demanding marine applications Maintains stable impact toughness at -60°C for reliable extreme cold climate performance Specifically designed for high-strength vessels operating in polar, arctic, and cryogenic marine environments Superior weldability and formability for efficient shipyard fabrication in polar climates

Chemical Composition & Mechanical Properties of FH40 Steel

Chemical Composition (Typical, %)

C Si Mn P S Cu Cr Ni Nb V Ti Mo N Al
≤0.18 ≤0.50 0.90 – 1.60 ≤0.035 ≤0.035 ≤0.35 ≤0.20 ≤0.40 0.02 – 0.05 0.05 – 0.10 ≤0.02 ≤0.08 - ≥0.015

i Chemical Element Explanations

C (Carbon): ≤0.18% - Influences strength and hardness.
Si (Silicon): ≤0.50% - Increases strength, deoxidizer.
Mn (Manganese): 0.90-1.60% - Enhances strength and toughness, desulfurizer.
P (Phosphorus): ≤0.035% - Harmful element, reduces toughness.
S (Sulfur): ≤0.035% - Harmful element, causes hot shortness.
Cu (Copper): ≤0.35% - Improves corrosion resistance.
Cr (Chromium): ≤0.20% - Improves corrosion resistance and hardness.
Ni (Nickel): ≤0.40% - Enhances toughness and low-temperature properties.
Nb (Niobium): 0.02-0.05% - Refines grain structure, improves strength.
V (Vanadium): 0.05-0.10% - Refines grain structure, improves toughness.
Ti (Titanium): ≤0.02% - Refines grain, fixes carbon and nitrogen.
Mo (Molybdenum): ≤0.08% - Improves high-temperature strength and corrosion resistance.
N (Nitrogen): - (Controlled by production process)
Al (Aluminum): ≥0.015% - Deoxidizer, refines grain structure.

* Typical values according to classification society specifications. Actual limits may vary by approval.

Mechanical Properties of FH40 Steel

Thickness (mm) Yield Strength (MPa) Tensile Strength (MPa) Elongation (%) Impact Test Temperature Longitudinal Impact (KV2)/J Transverse Impact (KV2)/J
≤50 mm ≥390 MPa 510 – 660 MPa ≥20% -60°C 41 27
>50~70 mm ≥390 MPa 510 – 660 MPa ≥20% -60°C 46 31
>70~150 mm ≥390 MPa 510 – 660 MPa ≥20% -60°C 55 37

F-Grade Hull Steel: Strength Grade Comparison for Extreme Low-Temperature Applications

The following table compares different strength grades within the F-Grade hull steel series (all grades impact tested at -60°C), illustrating available options for increasing load-bearing capacity while maintaining the same exceptional -60°C impact toughness for polar and cryogenic service.

Comparison of F-Grade Marine Steel Plates for Polar & Cryogenic Shipbuilding Applications
Steel Grade Impact Test Temperature Yield Strength (Minimum) Typical Application Environment
FH40 -60°C ≥ 390 MPa Ultimate choice for critical high-stress areas of icebreakers, LNG containment systems, and Arctic offshore structures.
FH32 -60°C ≥ 315 MPa Entry-level polar grade for vessels and structures in extreme cold where standard strength suffices.
FH36 -60°C ≥ 355 MPa High-strength option for polar vessels and offshore platforms where 355 MPa yield strength is required.

40-Class Hull Steel: Quality Grade Comparison for Different Temperature Requirements

This table compares different quality grades within the 40 Class high-strength hull steel series. All grades share the same high minimum yield strength (≥390 MPa) but are designed for drastically different service temperatures and marine environments, from standard to extreme polar conditions.

Comparison of 40-Class Steel Quality Grades for Different Marine Service Temperatures
Quality Grade Steel Grade Yield Strength (Minimum) Impact Test Temperature Key Selection Insight
Extreme Low-Temperature FH40 ≥ 390 MPa -60°C Premium-grade for ultimate environments. The highest standard grade, combining maximum strength with the best low-temperature toughness for icebreakers, LNG carriers, and critical Arctic infrastructure.
Standard Temperature AH40 ≥ 390 MPa 0°C High-strength option for standard marine applications in temperate and tropical waters. Cost-effective where -60°C toughness is not required.
Low-Temperature DH40 ≥ 390 MPa -20°C High-strength steel for cold climate operations (e.g., North Atlantic), offering reliable toughness at -20°C.
Enhanced Low-Temperature EH40 ≥ 390 MPa -40°C High-strength steel for severe arctic service and global ocean-going vessels, providing excellent toughness at -40°C.

Choose Your Optimal Marine Steel Grade

Compare key specifications across similar grades. Varying parameters are highlighted for quick decision-making.

FH40

CURRENT
Impact Test
-60°C ≥41J
Tensile Strength 510-660 MPa
Yield Strength (Min) ≥390 MPa
Key Feature Ultimate Performance

FH36

SUPER LOW
Impact Test
-60°C ≥34J
Tensile Strength 490-630 MPa
Yield Strength (Min) ≥355 MPa
Key Feature Extreme Cold

FH32

SUPER LOW
Impact Test
-60°C ≥31J
Tensile Strength 450-570 MPa
Yield Strength (Min) ≥315 MPa
Key Feature Entry-Level Polar

EH40

LOW TEMP
Impact Test
-40°C ≥41J
Tensile Strength 510-660 MPa
Yield Strength (Min) ≥390 MPa
Key Feature Arctic High-Strength

AH40

Standard Marine
Impact Test
0°C ≥41J
Tensile Strength 510-660 MPa
Yield Strength (Min) ≥390 MPa
Key Feature High-Strength Standard

DH40

HIGH STRENGTH
Impact Test
-20°C ≥41J
Tensile Strength 510-660 MPa
Yield Strength (Min) ≥390 MPa
Key Feature High-Strength Cold

Typical Applications of FH40 Marine Steel Plate

Arctic Heavy-Duty Hull & Load-Bearing Structures
FH40 steel plates are the **premium choice** for the most demanding **ice-going vessels and polar carriers**. The combination of **390 MPa minimum yield strength and -60°C impact toughness** provides an unmatched safety factor for hulls that must resist **intense ice crushing forces** while maintaining structural integrity in the world's coldest waters.
Large LNG Carrier Membrane Containment
In **large-capacity LNG carriers** employing membrane-type containment systems (like NO96 or Mark III), FH40 is specified for **secondary barrier and hull support structures**. Its **higher strength (390 MPa)** allows for weight optimization while its **-60°C toughness** guarantees safety against brittle fracture under cryogenic thermal contraction.
Heavy Icebreakers & Polar Heavy Equipment
**Powerful icebreakers, polar supply vessels, and offshore construction vessels** require materials that combine extreme low-temperature toughness with high strength. FH40 is used for their **bow frames, ice belts, and other high-stress zones** where both **impact resistance at -60°C and a 390 MPa yield strength** are critical to withstand continuous ice breaking and heavy equipment operations.
Arctic Fixed Platforms with High Load Capacity
**Gravity-based structures (GBS) and fixed jackets** in the Arctic demand materials that can support massive topside weights while enduring extreme cold. FH40 is selected for **critical nodes, legs, and submerged components** where its **390 MPa yield strength reduces material thickness** (aiding construction) and its **-60°C toughness ensures long-term fracture safety** under static and dynamic ice loads.
Cryogenic & High-Pressure Vessels
For **land-based and offshore cryogenic storage tanks, pressure vessels, and transport modules** that operate under both **extreme low temperature and high internal pressure**, FH40 offers a unique solution. The **elevated 390 MPa yield strength** allows for higher design pressures or thinner walls, while the **-60°C impact toughness** provides the essential safety against brittle fracture in service.

Available Sizes & Supply Conditions for FH40 Steel Plate

Dimensions

Thickness: 6 – 150 mm

Width: Up to 5,300 mm

Length: Up to 18,000 mm

Supply Conditions

Delivery Condition: Normalized (N) / Thermo-Mechanical Control Processed (TMCP) / Hot rolled / Controlled rolling
Standards: ASTM A131, EN 10025-3, JIS G3106, GB/T 712

Quality Control & Certification for FH40 Marine Steel

Inspection & Quality Control

• Chemical composition analysis and verification
• Tensile and elongation testing for mechanical properties
• Charpy V-notch impact testing at -60°C for toughness verification
• Ultrasonic testing (UT) for internal quality assessment
• Third-party inspection available (SGS, Bureau Veritas, TÜV, DNV, etc.)

Certification & Documentation

Each shipment includes comprehensive documentation:

✓ EN 10204 3.1 mill test certificate with full test results
✓ Classification society approval certificate (ABS, LR, BV, DNV, etc.)
✓ Heat number traceability for full material history
✓ Optional EN 10204 3.2 certificate available upon request

Why Choose CEHE Steel for Your Marine Steel Needs?

Discover how our expertise, resources, and commitment make us the preferred partner for marine steel solutions worldwide.

Powerful Resource Network and End-to-End Supply Assurance

Through alliances with 7 top-tier Chinese steel mills, we turn your custom steel requirements into reality—backed by classification society-certified inventory that stands ready to resolve rush orders and critical stockouts at a moment's notice.

Resource & Dimensions
Thickness: 6-150mm, Width: up to 5300mm, Length: up to 18000mm
Strategic Inventory
We have reserved a certain amount of CCS, ABS, BV, RINA in stock for you to quickly solve the urgent needs of ship body repair 
Global Logistics
Professional packaging with real-time tracking worldwide.
Supply Chain Control
We provide custom steel plate service with the fastest delivery cycle of up to 15 days.

Comprehensive Quality System and Transparent Traceability

We implement a quality control and traceability system that exceeds standard requirements, ensuring every steel plate we supply is reliable, compliant, and fully documented.

Full Certification
Meets ABS, DNV, GL, LR, BV, CCS, NK, RINA, KR standards.
Stringent Inspection
Third-party inspection support (SGS, BV) with rigorous internal QC.
Complete Traceability
Unique heat number tracking from mill to project.
Quality Standards
EN 10204 3.1/3.2 certificates with every shipment.

Technical Expertise and Comprehensive Project Support

We position ourselves not just as material suppliers but as technical partners, offering complete service from material selection through to final delivery and beyond.

Expert Consultation
Free technical guidance on material selection, welding, fabrication.
Project Follow-up
Immediate response, risk assessment, contract review, production tracking.
Value-Added Services
Export documentation, logistics arrangement, inspection coordination.
Continuous Support
From order confirmation to post-installation.

Proven Experience and Global Trust Since 2009

Since our founding in 2009, we have built deep expertise in marine steel applications and validated our capabilities through successful projects worldwide.

Industry Experience
Focused exclusively on marine steel since 2009
Global Performance
Successfully supplied major shipbuilding and offshore projects worldwide.
Trusted Partner
Long-term relationships with marine plate distributors and manufacturers.
Project Validation
Validated capabilities through successful global projects.

Frequently Asked Questions

FH40 is the **premium-grade** marine steel designed for the most demanding applications. It is used for **heavy-duty hull structures, ice belts, and critical load-bearing components** of vessels and offshore platforms operating in the **extreme Arctic/Antarctic** or in **cryogenic service (like LNG containment)**. Its combination of **390 MPa yield strength and -60°C impact toughness** makes it indispensable for projects where maximum structural integrity under severe低温 and high stress is non-negotiable.

The main advantage is **higher strength**. Both FH40 and FH36 offer the same exceptional **-60°C low-temperature toughness**, but FH40 has a **minimum yield strength of 390 MPa**, compared to FH36's 355 MPa. This makes FH40 the ultimate choice for applications that require the **highest possible load-bearing capacity alongside the best低温 toughness**, such as heavy icebreaker bow frames or high-stress zones of large LNG carrier membrane systems.

FH40 delivers the pinnacle of marine steel performance:
- **Yield Strength (Min): 390 MPa**
- **Tensile Strength: 510-660 MPa**
- **Impact Test Temperature: -60°C (-76°F)** with minimum energy typically ≥41J
This combination defines it as the highest standard grade for both strength and低温 toughness in shipbuilding classifications.

Each FH40 shipment is accompanied by comprehensive **EN 10204 3.1 mill test certificates**, providing full traceability and verified test results for **390 MPa yield strength and -60°C impact values**. Additionally, we supply **classification society approval certificates** (ABS, DNV, LR, BV, etc.) specifically validating the FH40 grade for polar and cryogenic applications.

Absolutely. We routinely supply FH40 with approvals from all major classification societies, including **ABS, BV, DNV, LR, CCS, NK, KR, and RINA**. Due to its use in high-specification projects, we are highly experienced in navigating the stringent certification process for this premium F-grade, high-strength steel and can collaborate directly with your nominated society.

Yes, and it is common practice for FH40 due to its critical applications. We can facilitate inspections by renowned third parties like **SGS, Bureau Veritas, TUV, or Lloyd's Register** to provide independent verification of the **-60°C impact tests, 390 MPa yield strength, and overall quality**, offering an extra layer of confidence for your high-value project.

Yes, customization is our strength, especially for top-tier grades like FH40. We can produce plates to your exact dimensional specifications (thickness, width, length) and meet any required classification society rules. **EN 10204 3.2 certificates** are also available.

Delivery Time: Due to the complex thermo-mechanical processing required, lead times for normalized or TMCP FH40 are typically **40-60 days**. Hot-rolled orders may be processed in approximately **25-30 days**, subject to mill scheduling.

Given its specialized nature, we offer **project-based MOQs for FH40**. Typical lead times are:
- **Hot-rolled:** ~25-30 days.
- **Normalized / TMCP:** ~40-60 days (due to stringent post-rolling treatment needed to achieve both 390 MPa and -60°C properties).
We work closely with clients to define feasible quantities and schedules for their specific high-performance project needs.

FH40 is a **premium product** with pricing that reflects its advanced metallurgy and stringent production controls. It carries a **significant premium** over EH40 and FH36. For a precise quotation, please provide detailed requirements: **grade (FH40), dimensions, quantity, delivery condition (N, TMCP), destination port, and required classification society approvals**. Contact our specialist sales team for a competitive quote tailored to your high-specification project.

**FH40 is exclusively a made-to-order product.** Due to its very specific and demanding combination of properties (390 MPa, -60°C), it is not held in general stock. Each order is produced against a specific project's requirements and certifications. This ensures you receive material that is precisely tailored and fully traceable to the highest standards. For availability and scheduling, please inquire directly with our sales team. → Contact for Project Inquiry.

Information You May Find Relevant

Pricing Range for FH40

Pricing is typically based on a benchmark price, with significant premiums applied for variations in thickness, width, and the advanced processing (Normalizing/TMCP) required to achieve both 390 MPa yield strength and -60°C toughness. To illustrate, let's assume a base price "a" (denoted in RMB) applies to thicknesses of 14–30mm and widths of 2000–2500mm: 12mm thickness: a + 50 (thickness premium) 10mm thickness: a + 150 (thickness premium) 8mm thickness: a + 350 (thickness premium) 32–40mm thickness: a + 50 (thickness premium) 42–50mm thickness: a + 100 (thickness premium) + 200 (normalizing surcharge) 50–52mm thickness: a + 150 (thickness premium) + 200 (normalizing surcharge)

Request Technical & Commercial Support

Get Professional Support for Your FH40 Project

We supply classification-approved **FH40 premium-grade shipbuilding steel plate** combining **390 MPa yield strength** with exceptional **-60°C impact toughness**. Ideal for the most demanding polar, cryogenic, and high-strength applications. Full traceability, stringent inspection, and project logistics coordination.

📋 Certification & Quality

• Adhere to the most stringent classification society rules for F-grade, high-strength steels

• Mill's EN 10204 3.1 certificate with verified -60°C and 390 MPa test data

• Third-party inspection (SGS, BV, etc.) strongly recommended for this premium grade

⚙️ Custom Solutions

• Precision cutting to your exact dimensions; widths ≤1600mm via split from double-width

• Full customization: CEV, PWHT simulation, Z-direction properties for critical joints

• Project-based scheduling: Hot-rolled (~25-30 days), Normalized/TMCP (~40-60 days)

Response Time: We typically respond to all inquiries within 24 hours

📩 Get FH40 Steel Plate Quotation

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