DH40 High Strength Hull Shipbuilding Steel Plate for Marine & Offshore Projects

  IACS Certified 390 MPa Yield Strength Steel with -20°C Impact Toughness  

Overview

The designation DH40 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 low-temperature toughness. Its core performance is characterized by a minimum yield strength of 390 MPa and reliable impact toughness at -20°C, making it an ideal choice for constructing vessels navigating temperate to cold climate waters.

Definition and Naming Logic

The designation DH40 originates from the International Association of Classification Societies (IACS) Unified Requirements.

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

First letter (D): Quality grade symbol, representing its impact toughness test temperature.
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 DH40 as a code, the correct and complete deciphering is:

"A high-strength shipbuilding structural steel requiring impact testing at -20°C, with a minimum yield strength of 390 MPa."

Value Proposition

Just like the karat standard for gold, the DH40 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 DH40 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 DH40 Procurement

We provide two procurement options for DH40 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 DH40 Ship Plates and Approved Classification Societies 

DH40 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, DH40 is typically prefixed with the specific classification society abbreviation to indicate compliance with that society's specific rules and approval requirements. For example, CCS DH40 (China Classification Society), ABS DH40 (American Bureau of Shipping), BV DH40 (Bureau Veritas), and DNV DH40 (Det Norske Veritas). The exception is the Russian Maritime Register of Shipping (RS), where the steel grade is designated as PC DH40.

Key Advantages of DH40 Steel Grade

Steel Grade
Balanced Strength Performance
Cold Climate Toughness
Marine Durability
Excellent Fabrication Properties
DH40 Marine Steel 390 MPa minimum yield strength provides optimal balance of strength and toughness for demanding marine applications Maintains stable impact toughness at -20°C for reliable cold climate performance Specifically designed for high-strength vessels operating in cold waters and challenging marine environments Superior weldability and formability for efficient shipyard fabrication in various climates

Chemical Composition & Mechanical Properties of DH40 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 DH40 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% -20°C 41 27
>50~70 mm ≥390 MPa 510 – 660 MPa ≥20% -20°C 46 31
>70~150 mm ≥390 MPa 510 – 660 MPa ≥20% -20°C 55 37

D-Grade Hull Steel: Strength Grade Comparison for Marine Applications

The following table compares different strength grades within the D-Grade hull steel series (all grades impact tested at -20°C), illustrating available options for increasing load-bearing capacity while maintaining the same -20°C impact toughness.

Comparison of D-Grade Marine Steel Plates for Shipbuilding Applications
Steel Grade Impact Test Temperature Yield Strength (Minimum) Typical Application Environment
DH40 -20°C ≥ 390 MPa High-stress primary structures for large vessels operating in cold waters; critical areas like hatch corners.
DH36 -20°C ≥ 355 MPa Primary structures for vessels in sub-arctic zones; exposed structural members.
DH32 -20°C ≥ 315 MPa General hull structures for vessels in temperate to cold climates.

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 minimum yield strength (≥390 MPa) but are designed for different service temperatures and marine environments.

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
 Low-Temperature DH40 ≥ 390 MPa -20°C High-strength steel with reliable low-temperature toughness for critical structures in cold climates.
Standard Temperature AH40 ≥ 390 MPa 0°C High-strength option for warmer climate applications with standard toughness.
Enhanced Low-Temperature EH40 ≥ 390 MPa -40°C High-strength steel for global ocean-going vessels in extreme cold conditions.
Extreme Low-Temperature FH40 ≥ 390 MPa -60°C Premium high-strength steel for icebreaking vessels and Arctic offshore structures.

Choose Your Optimal Marine Steel Grade

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

DH40

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

AH40

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

EH40

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

FH40

SUPER LOW
Impact Test
-60°C ≥41J
Tensile Strength 510-660 MPa
Yield Strength (Min) ≥390 MPa
Key Feature Extreme Cold

DH36

STANDARD STRENGTH
Impact Test
-20°C ≥34J
Tensile Strength 490-630 MPa
Yield Strength (Min) ≥355 MPa
Key Feature Standard High-Strength

DH32

LOWER STRENGTH
Impact Test
-20°C ≥31J
Tensile Strength 450-570 MPa
Yield Strength (Min) ≥315 MPa
Key Feature Economical Option

Typical Applications of DH40 Marine Steel Plate

High-Strength Hull Structures
DH40 steel plates are the premium choice for constructing the high-stress hull structures of large vessels operating in challenging environments like the North Atlantic and Arctic. Their 390 MPa minimum yield strength ensures structural integrity under extreme loads and ice pressure.
Decks & Bulkheads
For marine decks and bulkheads on large vessels, DH40 provides an optimal balance of high strength and toughness. This makes it ideal for critical areas that require reliable performance in cold climate shipbuilding, offering excellent weldability and impact resistance at temperatures as low as -20°C.
Critical Structural Components
A wide range of critical marine structural components are fabricated from DH40 due to its guaranteed 390 MPa yield strength and -20°C impact toughness. This combination is essential for parts subjected to dynamic stresses in harsh marine conditions, ensuring long-term durability and safety.
Critical Areas of Large Vessels
The superior strength-to-weight ratio of DH40 marine steel is critical for the safety of large vessels operating in demanding conditions. It is commonly used in hatch corners, bilge strakes, sheer strakes, and other high-stress areas where maximum strength is required.
Offshore Critical Structures
Offshore oil and gas platforms in harsh environments utilize DH40 steel for critical structural sections. Its 390 MPa yield strength ensures stability and integrity under the combined loads of wind, waves, and ice, which is paramount for the safety of these critical infrastructures.

Available Sizes & Supply Conditions for DH40 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) / Quenched and Tempered (QT)
Standards: ASTM A131, EN 10025-3, JIS G3106, GB/T 712

Quality Control & Certification for DH40 Marine Steel

Inspection & Quality Control

• Chemical composition analysis and verification
• Tensile and elongation testing for mechanical properties
• Charpy V-notch impact testing at -20°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

DH40 is primarily used for high-strength hull structures, critical areas of large vessels, decks, bulkheads, and marine components operating in cold waters. It is ideal for applications requiring superior performance with 390 MPa yield strength and reliable -20°C impact toughness in demanding marine environments.

The main difference is yield strength. Both DH40 and DH36 are impact tested at -20°C, but DH40 has a higher minimum yield strength of 390 MPa, while DH36 is 355 MPa. DH40 provides superior load-bearing capacity for critical applications requiring maximum strength while maintaining the same cold temperature toughness.

DH40 is impact tested at -20°C (-4°F) in accordance with classification society requirements for cold climate marine service conditions, same as DH36 and DH32 but with higher strength requirements.

We provide EN 10204 3.1 mill test certificates along with classification society approval certificates for each shipment, including specific documentation for -20°C impact testing and 390 MPa yield strength verification.

Yes, we can supply DH40 plates with certifications from major classification societies including ABS (American Bureau of Shipping), BV (Bureau Veritas), DNV (Det Norske Veritas), LR (Lloyd's Register), CCS (China Classification Society), NK (Nippon Kaiji Kyokai), KR (Korean Register), and RINA. We can work with your designated classification society to meet specific project requirements for high-strength applications.

Yes, we can arrange third-party inspections from organizations like SGS, Bureau Veritas, TUV, or Lloyd's Register upon customer request, including verification of -20°C impact test results and 390 MPa yield strength testing.

Yes, we specialize in customized solutions. We can supply DH40 plates according to your specified dimensions, thicknesses, and classification society requirements for high-strength applications. We also provide EN 10204 3.2 certificates upon request.

Delivery time for customized orders: Approximately 20-25 days for TMCP plates and 40-60 days for normalized or QT plates, depending on specifications.

We offer flexible MOQ options. For TMCP plates, typical lead time is around 20-25 days. For normalized or QT plates, expect 40-60 days depending on specifications and quantity. We can accommodate smaller quantities for high-strength shipbuilding steel plates between 10-50mm based on your specific needs.

The price of DH40 steel plate fluctuates based on raw material costs, thickness, dimensions, purchase volume, and market conditions. DH40 typically commands a premium over DH36 due to its higher strength specifications and more complex processing requirements. For the most accurate and competitive real-time quotation, please contact our sales team with your specific requirements (grade, size, quantity, destination port, and any special certifications needed). We provide competitive pricing and respond within 24 hours.

For high-strength marine steel plates (including DH40), our business strategy is customization-oriented, supplemented by spot inventory. We maintain limited spot inventory of DH40 for urgent requirements, though due to the specialized nature of high-strength plates, most orders are production-based. If you have an urgent requirement, please contact our sales team directly to check current availability. For specific inquiries, you can also use our stock inquiry system → stock inquiry system.

Information You May Find Relevant

Pricing Range for DH40

Pricing is typically based on a benchmark price, with additional premiums applied for variations in thickness, width, and supplementary processing requirements. As a higher-strength grade, DH40 commands a premium over DH36 due to more stringent chemical composition control and heat treatment requirements. For specific pricing based on your required specifications and quantity, please contact our sales team.

Request Technical & Commercial Support

Get Professional Support for Your DH40 Project

We supply classification-approved DH40 high-strength shipbuilding steel plate with -20°C impact toughness, 390 MPa yield strength, full traceability, flexible inspection options, and coordinated logistics support.

📋 Certification & Quality

• Adhere to classification society specifications and corresponding manufacturing standards

• Mill's EN 10204 3.1 certificate included in quality documentation

• Third-party onsite certification available upon request for customized plates

⚙️ Custom Solutions

• Custom thickness, width, length; widths ≤1600mm can be supplied via split delivery from double-width rolling

• 100% customizable: carbon equivalent, simulated post-weld, Z-direction properties, etc.

• Fastest delivery for TMCP custom plates: 15-20 days

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

📩 Get DH40 Steel Plate Quotation

📝 Maximum 10 rows can be entered in this table. If you need more rows, please enter detailed requirements in the text box below, or send them to us via email.

Material Thickness (mm) Width (mm) Length (mm) Quantity Weight (ton) Action

You will receive a confirmation email after submission, and we will respond within 24 hours.