5083-H116 is a marine-grade, strain-hardened aluminum alloy specifically designed for shipbuilding applications. It offers high yield strength, excellent weldability, and supreme resistance to exfoliation and intergranular corrosion in severe seawater environments.
When shipyard engineers from Southeast Asia or Europe come to GNEE with blueprint specifications, the material most frequently called out for the vessel's hull is 5083-H116. However, many procurement managers simply ask for "5083 aluminum," failing to realize that ordering the wrong temper can lead to catastrophic structural failure and massive class-inspection rejections.
In this technical guide, we break down exactly what 5083 H116 is, why it rules the marine industry, and how to properly source it for your next maritime project.
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Definition of 5083-H116 Marine Aluminum Plate
At its core, the 5083-H116 marine aluminum plate is an Aluminum-Magnesium (Al-Mg) alloy. It contains a high magnesium content, strictly controlled between 4.0% and 4.9%. This specific chemical composition gives the metal its foundational strength without the need for heat treatment.
In practical shipbuilding projects, 5083-H116 is commonly used for outer hull plating, bottom structures, and deck assemblies of patrol boats, passenger ferries, and luxury yachts. Because it does not rely on thermal treatments for strength, it retains exceptional structural integrity even after heavy continuous welding-a critical requirement for assembling large ship modules.
5083-H116 Chemical Composition Limit (Weight %)
| Alloy | Mg (%) | Mn (%) | Cr (%) | Fe (%) | Si (%) | Zn (%) | Ti (%) | Cu (%) | Al (%) |
|---|---|---|---|---|---|---|---|---|---|
| 5083 | 4.0 – 4.9 | 0.4 – 1.0 | 0.05 – 0.25 | ≤ 0.40 | ≤ 0.40 | ≤ 0.25 | ≤ 0.15 | ≤ 0.10 | Remainder |
What Does "H116" Mean in 5083 Shipbuilding Aluminum?
The "5083" designates the chemical alloy, but the "H116" specifies the temper (the thermomechanical processing history).
For 5000-series alloys with more than 3.0% magnesium, long-term exposure to marine environments can cause a metallurgical issue: magnesium atoms can precipitate at the grain boundaries, making the metal highly susceptible to a destructive condition known as exfoliation corrosion (where the metal peels apart in layers like an onion).
The H116 temper was engineered specifically to solve this. "H1" means the metal is strain-hardened (cold-worked) to increase its physical strength. The "16" indicates a specialized continuous temperature control process specific to Al-Mg alloys. This process stabilizes the micro-structure, locking the magnesium in place and ensuring the 5083 shipbuilding aluminum remains immune to intergranular corrosion for decades in saltwater.
Key Mechanical Properties of EN 5083 H116 Aluminum Sheet
Engineers need hard data. To pass international maritime safety codes, marine grade aluminum 5083 must meet strict mechanical baselines. Below are the standard mechanical properties for GNEE's 5083-H116 plates (typically applicable for thicknesses between 3mm and 50mm).
| Mechanical Property | Value (Metric) | Value (Imperial) | Significance in Shipbuilding |
| Tensile Strength (Rm) | ≥ 305 MPa | ≥ 44 ksi | Ultimate breaking point under tension. |
| Yield Strength (Rp0.2) | ≥ 215 MPa | ≥ 31 ksi | The point where the hull will permanently deform. |
| Elongation (A50) | ≥ 10% | ≥ 10% | Indicates ductility, allowing the hull to absorb wave impact. |
| Corrosion Resistance | Excellent | Excellent | Passes ASTM G66 ASSET & ASTM G67 NAMLT tests. |
Why 5083-H116 Alloy is the Standard for Marine Applications
Why do marine architects specifically write 5083-H116 into their blueprints instead of cheaper alternatives?
- Immunity to Rust and Seawater: Does 5083 aluminum rust in seawater? No. Because it contains no iron, it cannot rust. Furthermore, the 5083-H116 alloy instantly forms a tough, self-healing microscopic aluminum oxide layer upon exposure to oxygen. If a ferry scrapes against a dock, the scratched aluminum instantly re-oxidizes, preventing further degradation.
- Post-Weld Strength: Many strong aluminum alloys (like the 6000 series) lose up to 50% of their strength in the Heat Affected Zone (HAZ) during welding. 5083-H116 is non-heat-treatable. When welded with ER5183 or ER5356 filler wire, the welded joint remains incredibly strong, ensuring the ship's watertight integrity.
- Lightweight Economics: Weighing only one-third of steel, 5083-H116 allows shipbuilders to design vessels with shallower drafts, faster top speeds, and significantly reduced fuel consumption.
5083 H116 vs 5083 H321 vs 5083-O Aluminum Plates
When sourcing materials, you might see different tempers available. Using the wrong one is a costly mistake. Here is the definitive comparison:
| Alloy & Temper | Processing Method | Primary Application | Should You Use It For Hulls? |
| 5083-O | Fully Annealed (Softest state) | Deep drawn parts, non-structural interior components. | NO. Yield strength is too low (~125 MPa). |
| 5083 H116 | Strain-hardened specifically for high-Mg alloys. | Submerged ship hulls, bottom plating, marine armor. | YES. Supreme exfoliation resistance. |
| 5083 H321 | Strain-hardened + low-temperature stabilization. | Submerged ship hulls, pressure vessels, decking. | YES. Completely interchangeable with H116 in most marine codes. |
Note: While H116 and H321 undergo slightly different manufacturing routes, both are certified under ASTM B928 and perform identically in the ocean.
Standards and KR Certifications for 5083 Marine Metal
You cannot build a commercial vessel with standard commercial-grade metal. The material must be certified.
The globally recognized standard for marine aluminum is ASTM B928/B928M (Standard Specification for High Magnesium Aluminum-Alloy Sheet and Plate for Marine Service). Any 5083 H116 material must pass the ASSET test (for exfoliation) outlined in this standard.
More importantly, the material requires classification society approval. At GNEE, we are a direct manufacturer equipped to supply KR (Korean Register) Certified 5083 aluminum plates. We also provide DNV, ABS, LR, and CCS certifications. All plates are supplied with full traceability, including a rigorous Mill Test Certificate (MTC 3.1 or 3.2).
Typical Applications of 5083 H116 Aluminum Alloy in Shipyards
Based on our export experience supplying shipyards across Southeast Asia and Europe, 5083-H116 is deployed in high-stress zones:
Patrol Boats and Interceptors: Used for the primary V-hull and armor plating due to high yield strength.
Passenger Ferries and Catamarans: Used for massive hull pontoons where continuous welding is required.
Offshore Platforms: Utilized for gangways and splash-zone structural supports.
Available Sizes and Supply Capability at GNEE
As a factory-direct marine grade aluminum 5083 supplier, GNEE understands that standard dimensions often lead to excessive welding and material waste. We provide engineering-optimized parameters for shipyards:
- Most Common Hull Thicknesses: 4 mm / 5 mm / 6 mm / 8 mm
- Heavy Duty Thicknesses: 10 mm up to 50 mm for engine beds and bulkheads.
- Optimal Marine Size: 2000 mm × 8000 mm.
(Using an 8-meter long plate significantly reduces the number of weld seams on your hull, saving labor and reducing thermal distortion).
Stop risking your project on uncertified metals.
All GNEE marine plates are supplied with full traceability and marine certification.
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