Marine Bulb Flat Steel AH32 AH36 A Grade For Shipbuilding Hull Stiffeners
Product Description
Marine Bulb Flat Steel for Shipbuilding Hull Stiffeners — AH32 AH36 A Grade, ABS DNV LR Certified
Our Marine Bulb Flat Steel is hot-rolled from high-quality shipbuilding steel, specifically designed as plate stiffeners for hull structures in commercial vessels, offshore platforms, and naval auxiliaries. Compared with flat bars or angle steel, bulb flats deliver higher buckling resistance at a lighter weight, and their rounded edges eliminate the need for edge grinding before painting — saving both time and cost in the shipyard.
Available Specifications
| Width (b) | Thickness (t) | Height (h) | Theoretical Weight |
|---|---|---|---|
| 80 mm | 5 mm | 19 mm | 4.25 kg/m |
| 100 mm | 7 mm | 22.5 mm | 6.86 kg/m |
| 120 mm | 8 mm | 25 mm | 9.20 kg/m |
| 140 mm | 8 mm | 27 mm | 10.85 kg/m |
| 160 mm | 9 mm | 31 mm | 13.97 kg/m |
| 180 mm | 10 mm | 35 mm | 17.63 kg/m |
| 200 mm | 10 mm | 38 mm | 20.14 kg/m |
| 240 mm | 11 mm | 45 mm | 27.39 kg/m |
| 280 mm | 12 mm | 52 mm | 35.70 kg/m |
| 320 mm | 13 mm | 59 mm | 45.09 kg/m |
| 370 mm | 14 mm | 67.5 mm | 57.60 kg/m |
| 430 mm | 19 mm | 81 mm | — |
Standard length: 6m–16.5m. Custom cutting available.
Steel Grades & Certification
| Strength Level | Grade | Yield Strength (min) | Classification Society Approvals |
|---|---|---|---|
| Normal Strength | A, B, D, E | 235 MPa | ABS, DNV, LR, BV, CCS, GL, KR, NK |
| High Strength | AH32 | 315 MPa | ABS, DNV, LR, BV, CCS, GL, KR, NK |
| High Strength | AH36 | 355 MPa | ABS, DNV, LR, BV, CCS, GL, KR, NK |
Mill Test Certificate EN 10204 3.1/3.2 available. All material supplied with visible heat number stamping and bundle labels for full traceability.
Key Features
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Weight Optimization — The bulb profile provides the same stiffening effect as an angle or flat bar at significantly reduced weight, directly improving vessel deadweight capacity.
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Corrosion-Friendly Design — Rounded edges and smooth transitions eliminate sharp corners where paint tends to thin out, extending coating life and reducing maintenance costs.
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High Buckling Resistance — The bulb head resists lateral buckling under compression loads far better than flat bars of equivalent weight.
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Certified for Marine Use — Produced under ABS, DNV, LR, and BV approvals. Ideal for hull stiffeners, deck beams, bulkhead stiffeners, and offshore structure reinforcement.
Applications
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Commercial Shipbuilding — Bulk carriers, container ships, tankers, general cargo vessels
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Offshore Structures — Oil rigs, wind turbine foundations, FPSO units
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Naval Auxiliaries — Frigates, sealift ships, patrol vessels
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Bridge & Steel Structure — Plate stiffening in heavy steel construction
Packing & Delivery
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Packing: Bundled with steel wire; heat number stamped on each piece; weather-resistant bundle labels
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Loading: 20GP / 40GP container or bulk vessel
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Lead Time: 7–30 days depending on quantity and certification requirements
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.