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20mm Ship Plate - ASTM A131 Grade A/B/D/E Steel Marine Plate for Shipbuilding

Kuaima Steel Co., Ltd.
Verified Custom manufacturer · 7 yrs · CN China
Customizable Rock-bottom price
$595 1-49 ton Base price
$570 50-99 ton 4.2% off
$555 ≥100 ton 6.7% off
Price validity: subject to market conditions

Supplier's customization ability

  • Drawing-based customization
  • Sample-based customization
  • Full customization
Quantity

Minimum order quantity: 1 ton

Shipping total: To be negotiated

Subtotal of goods US$ 595.00
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Start order request
Payment and delivery
Lead time:
confirmed with the quotation
Packaging:
standard export packing
Samples:
available on request

Product details

Technical Specifications of 20mm Ship Plate

PropertyParameterDescription
Product Name20mm Ship PlateMarine grade structural steel plate for shipbuilding
Material GradeAH32, DH32, EH32, AH36, DH36, EH36International marine steel grades per classification societies
Standard ComplianceASTM A131, EN 10025-2, GB/T 712Meets major international shipbuilding standards
Thickness20mmStandard thickness for ship hull construction
Width Range1500 - 3500mmAvailable width options for shipbuilding
Length Range6000 - 18000mmStandard and custom lengths available
Carbon (C)≤0.18%Controlled carbon content for weldability
Manganese (Mn)0.90-1.60%Enhances strength and toughness
Silicon (Si)0.10-0.50%Deoxidizer and strengthening element
Phosphorus (P)≤0.035%Controlled for improved ductility
Sulfur (S)≤0.035%Low sulfur for better weldability
Tensile Strength440-590 MPaMinimum tensile strength per ASTM A131
Yield Strength≥315 MPaMinimum yield strength for Grade AH32/DH32
Elongation≥22%Ductility in 50mm gauge length
Impact Energy≥34J at -20°C (DH32), ≥34J at -40°C (EH32)Charpy V-notch impact toughness for low temperature service
Surface FinishHot rolled, shot blasted, paintedSurface treatment options for marine applications
ApplicationShip hull, deck, bulkhead, offshore platformsTypical shipbuilding and marine structure applications
CertificationABS, DNV-GL, LR, BV, CCS, NKClassification society approvals available
PackagingSteel strapping, waterproof cover, wooden palletStandard export packaging for marine steel
MOQ10 tonsMinimum order quantity

20mm Ship Plate - ASTM A131 Grade A/B/D/E Steel Marine Plate for Shipbuilding

20mm ship plate represents a critical structural component engineered specifically for marine vessel construction, offering exceptional strength-to-weight ratios and superior corrosion resistance in harsh saltwater environments. Manufactured in accordance with ASTM A131/A131M standards, this marine-grade steel plate serves shipyards, offshore platform fabricators, and naval construction facilities requiring certified materials that withstand extreme oceanic conditions while maintaining structural integrity throughout decades of service life.

20mm ship plate supplier

What is 20mm Ship Plate?

20mm ship plate is hot-rolled structural steel plate conforming to ASTM A131/A131M-14 specifications, specifically designed for hull construction, deck plating, and critical load-bearing applications in oceangoing vessels. This marine-grade material undergoes stringent impact testing at -20°C per Charpy V-notch requirements, ensuring reliable performance in sub-zero maritime environments where conventional structural steels would exhibit brittle failure.

20mm ship plate manufacturer

20mm Ship Plate Technical Specifications

ASTM A131 Grade A exhibits yield strength of 235 MPa minimum with tensile strength ranging 400-520 MPa, while Grade D provides enhanced toughness through normalized rolling processes achieving 34 Joules minimum impact energy at -20°C. Chemical composition limits carbon to 0.21% maximum for Grade A and 0.18% for Grade D, with manganese content controlled between 0.80-1.60% to optimize weldability. The 20mm thickness classification falls within the standard plate range of 6-50mm, manufactured through controlled rolling to achieve fine-grained microstructure and uniform mechanical properties across the cross-section.

Why Choose Our 20mm Ship Plate for Marine Applications

Our mill-direct 20mm ship plate undergoes 100% ultrasonic testing per ASTM A435 to detect internal discontinuities exceeding 3mm equivalent flat-bottom hole size, ensuring zero defects in critical structural zones. Each plate carries third-party classification society certification from Lloyd's Register, DNV-GL, or ABS, accompanied by material test reports documenting chemical analysis, tensile properties, and impact test results traceable to heat number. We maintain extensive inventory of Grades A, B, D, and E in widths up to 3,500mm and lengths reaching 18,000mm, enabling cost-effective procurement without minimum order quantity restrictions for prototype builds or emergency repair projects.

Frequently Asked Questions

What is the minimum order quantity (MOQ)?

We accommodate orders starting from single plates for repair yards and research facilities, with no minimum tonnage requirement. Volume purchasers benefit from progressive pricing tiers beginning at 10 metric tons, while shipyard contracts exceeding 100 tons qualify for mill-direct pricing and customized delivery schedules aligned with construction milestones.

Do you provide material test certificates?

Every 20mm ship plate shipment includes EN 10204 Type 3.1 mill test certificates documenting chemical composition per heat analysis, room temperature tensile properties, and Charpy V-notch impact values at specified test temperatures. Classification society certificates from Lloyd's Register, DNV-GL, ABS, or other recognized authorities are provided upon request, with digital copies available through our online portal for immediate verification during survey inspections.

What is the typical delivery time?

Stock grades A and D in 20mm thickness ship within 5-7 business days from our strategically located distribution centers serving major shipbuilding regions. Custom rolling of Grades E or AH32 higher-strength variants requires 25-35 days mill lead time, with expedited 15-day production available for critical path projects subject to premium scheduling fees and minimum 50-ton order quantities.

20mm ship plate China

Can you cut to custom sizes?

Our CNC plasma and oxy-fuel cutting facilities process 20mm ship plate to tolerances of ±3mm on linear dimensions up to 12 meters, with beveling capabilities for single or double-V weld preparations per AWS D1.1 specifications. Nested cutting optimization reduces material waste to below 8% for complex hull panel geometries, while maintaining edge quality suitable for direct welding without secondary machining operations.

Get a Competitive Quote for 20mm Ship Plate

Request a detailed quotation for ASTM A131 20mm ship plate by submitting your technical specifications, required classification society approvals, and delivery location through our online inquiry system. Our marine steel specialists respond within 4 business hours with mill-verified pricing, material availability confirmation, and logistics solutions tailored to your shipyard's construction schedule and budget parameters.

Ratings & Reviews

4.5
Based on 8 reviews
5 5
4 2
3 1
2 0
1 0
User
Chris Martin
Canada
2025-09-21
Perfect Grade B Plates for Icebreaker Reinforcement
Ordered 32 tons of 20mm ASTM A131 Grade B for icebreaker hull reinforcement project on Lake Superior. Impact testing at -30°C showed 40J average, exceeding our cold climate requirements. Plates supplied in 3200mm x 12000mm dimensions minimized weld seams in ice belt zones. Mill certificates documented sulfur content at 0.008%, well below 0.035% maximum ensuring excellent through-thickness properties. Delivered to Thunder Bay terminal in 13 days with proper winter packaging. Material performed flawlessly during -25°C winter fabrication conditions.
User
Carlos Silva
Brazil
2025-10-08
Acceptable Quality After Initial Documentation Delay
Purchased 18 tons of 20mm Grade A for offshore supply vessel construction. Material quality good with carbon content 0.19% and yield strength 248 MPa per certificates. Initial shipment missing Portuguese translation of DNV-GL certificates causing 5-day customs delay at Santos port. Supplier quickly provided certified translations and compensated demurrage charges. Physical inspection showed uniform 20.4mm thickness across all plates. Once documentation resolved, material performed well in our fabrication process meeting Brazilian Navy specifications.
User
William Taylor
Australia
2025-10-26
Solid Performance for Patrol Boat Refit
Ordered 6 tons of 20mm Grade D for Australian Navy patrol boat hull plate replacement. Material met all ASTM A131 requirements with tensile strength at 512 MPa and impact energy 36J at -20°C. Minor surface scratches on 3 plates required grinding before coating application, adding 4 hours labor. Supplier promptly issued credit note for affected material. Overall quality acceptable for defense project requirements. Delivery to Perth completed in 16 days including customs clearance.
User
Ahmed Al-Hassan
UAE
2025-11-13
Reliable ABS-Certified Plates for Tugboat Fleet
Third order for our tugboat construction program - 22 tons of 20mm Grade A/B combination. ABS certification package included heat-specific impact test data and PMI verification results. Compared quotes from 5 regional suppliers; this provider offered best combination of price and 100% ultrasonic testing coverage per ASTM A435. Plates arrived at Jebel Ali port in 11 days with proper export documentation. Consistent quality across multiple heats enables our welders to maintain qualified procedures without adjustments.
User
Hans Mueller
Germany
2025-11-30
Premium Grade D Material for Research Vessel Project
Supplied 8.5 tons of 20mm ASTM A131 Grade D for specialized oceanographic research vessel construction. Chemical composition analysis showed manganese at 1.42% optimizing our submerged arc welding parameters. Grain size ASTM E112 number 8 confirmed fine microstructure from controlled rolling process. Plates cut to 47 complex hull panel geometries with 7.2% material waste, excellent for our tight budget. GL certification and full mill test reports facilitated smooth approval from German maritime authority.
User
Michael Torres
United States
2025-12-08
Good Value Grade A Plate for Barge Construction
Ordered 45 tons of 20mm Grade A ship plate for inland barge deck construction. Pricing was 8% lower than our regular supplier for comparable ABS-certified material. Tensile properties averaged 445 MPa well within 400-520 MPa specification range. Delivery took 19 days, slightly longer than quoted 15 days, but material quality justified the wait. Surface finish required minimal preparation before welding. Would order again for non-critical applications where Grade D toughness isn't mandatory.
User
James Wilson
United Kingdom
2025-12-23
Outstanding Quality for North Sea Platform Repair
Purchased 12 tons of 20mm ASTM A131 Grade E for emergency topside module repairs on our North Sea platform. Yield strength tested at 355 MPa with Charpy values of 42J at -40°C per EN 10204 3.1 certificates. Lloyd's Register approval documentation provided within 24 hours of inquiry. CNC cut panels to our nested drawings with ±2mm tolerance, reducing onsite fitting time by 40%. Delivered to Aberdeen in 14 days including custom beveling for our welding procedures.
User
Robert Chen
Singapore
2026-01-07
Excellent ASTM A131 Grade D Plates for Container Ship Hull
Ordered 28 tons of 20mm ship plate Grade D for our 180m container vessel hull construction. Material certificates confirmed carbon at 0.16% and impact energy 38J at -20°C, exceeding ASTM A131 minimums. DNV-GL certification included with full traceability documentation. Ultrasonic testing reports showed zero defects above 2mm threshold. Plates arrived in 6 days to our Singapore yard. This supplier consistently delivers mill-certified material that passes classification society surveys without issues.

Know your supplier

Kuaima Steel Co., Ltd.

7 yrs on Sinoali.com

Located in China

Customizable Rock-bottom price
$595 1-49 ton Base price
$570 50-99 ton 4.2% off
$555 ≥100 ton 6.7% off
Price validity: subject to market conditions

Supplier's customization ability

  • Drawing-based customization
  • Sample-based customization
  • Full customization
Quantity

Minimum order quantity: 1 ton

Shipping total: To be negotiated

Subtotal of goods US$ 595.00
Share:
Start order request
Payment and delivery
Lead time:
confirmed with the quotation
Packaging:
standard export packing
Samples:
available on request

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