H116
Strain-hardened with controlled processing so that the plate meets both strength and corrosion-test requirements. Widely used for hull shell, decks and bulkheads.
Shipbuilding hull plate
5083 Marine Grade Aluminium Plate (H116 / H321)
5083 is the standard aluminium alloy for welded ship and boat hulls. In the H116 and H321 tempers it combines a minimum yield of 215 MPa with proven resistance to exfoliation and intergranular corrosion, and it keeps most of its strength after welding. Metline supplies 5083 plate in H116, H321, H111 and O to ASTM B928, EN 485 and classification-society rules, worldwide.
- Alloy
- 5083 (Al-Mg4.5-Mn)
- Tempers
- H116, H321, H111, O, H112
- Min yield H116/H321
- 215 MPa
- Standards
- ASTM B928 · EN 485 · IACS W25
Why 5083 is the default hull alloy
5083 contains 4.0 – 4.9 % magnesium, 0.4 – 1.0 % manganese and a little chromium. It is the strongest of the widely available non-heat-treatable aluminium alloys, and because its strength comes from solid solution and cold work rather than precipitation hardening, welding reduces it only to the annealed level rather than destroying it.
That welded strength, combined with outstanding resistance to seawater, is why 5083 has been the backbone of aluminium shipbuilding for decades: ferries, workboats, patrol craft, fishing vessels, yachts, superstructures on steel ships, and offshore modules. It also keeps its toughness at very low temperature, which makes 5083-O a standard material for LNG tanks and cryogenic vessels.
For hull use the temper matters as much as the alloy. Ordinary strain-hardened tempers such as H32 can become susceptible to exfoliation when the magnesium-rich beta phase forms continuous films at grain boundaries. The H116 and H321 tempers are produced and tested specifically to avoid this, and are the only rolled tempers that classification rules accept for most hull plating.
5083 chemical composition
ASTM, EN, JIS and the IACS rules all use the registered Aluminum Association limits. Each plate is branded with its cast or batch number and certified with the actual analysis.
| Element (wt %) | 5083 |
|---|---|
| Silicon (Si) | 0.40 |
| Iron (Fe) | 0.40 |
| Copper (Cu) | 0.10 |
| Manganese (Mn) | 0.40 – 1.0 |
| Magnesium (Mg) | 4.0 – 4.9 |
| Chromium (Cr) | 0.05 – 0.25 |
| Zinc (Zn) | 0.25 |
| Titanium (Ti) | 0.15 |
| Others, each / total | 0.05 / 0.15 |
| Aluminium (Al) | Remainder |
Single figures are maximums. Manganese and chromium form dispersoids that control grain structure and add strength.
Mechanical properties of 5083 marine plate
Specified minimums from IACS UR W25 for plate 3 – 50 mm. ASTM B928 gives the same values up to about 40 mm and lower minimums for thicker plate (for H116 / H321 from 40 to 80 mm: tensile 285 MPa, yield 200 MPa).
| Alloy | Temper | Thickness | Yield Rp0.2 min (MPa) | Tensile Rm (MPa) | Elongation A50 / A5 min (%) |
|---|---|---|---|---|---|
| 5083 | O / H111 | 3 – 50 mm | 125 | 275 – 350 | 16 / 14 |
| 5083 | H112 | 3 – 50 mm | 125 | 275 | 12 / 10 |
| 5083 | H116 | 3 – 50 mm | 215 | 305 | 10 / 10 |
| 5083 | H321 | 3 – 50 mm | 215 – 295 | 305 – 385 | 12 / 10 |
| Temper | Typical tensile strength | Typical yield strength | Typical elongation |
|---|---|---|---|
| O / H111 | about 290 MPa | about 145 MPa | about 22 % |
| H116 / H321 | about 317 MPa | about 228 MPa | about 16 % |
Typical values from ASM and Aluminum Association data, for guidance only. Design to specified minimums and to the welded values given in the applicable rules.
Physical properties of 5083
- Density
- 2.66 g/cm³ (0.096 lb/in³)
- Modulus of elasticity
- about 71 GPa
- Thermal conductivity
- about 117 – 121 W/m·K
- Electrical conductivity
- about 29 % IACS
- Coefficient of thermal expansion
- about 24 µm/m·°C (20 – 100 °C)
- Melting range
- about 574 – 638 °C
5083 tempers explained
H321
Strain-hardened and thermally stabilised, with a controlled maximum strength. Same minimums as H116 under UR W25, certified separately.
H111
Annealed and slightly strain-hardened. Used where plates are formed heavily, and for many offshore and pressure applications.
O
Fully annealed. For deep forming and cryogenic tanks; LNG containment commonly uses 5083-O.
H112
As hot-rolled, mainly for thicker plate. Listed for marine use with lower minimum strength than H116.
H32 (not for hulls)
A general-engineering temper without the marine corrosion controls. Fine for many industrial uses, but not a substitute for H116 / H321 in hull plating.
Exfoliation and intergranular corrosion testing
Under IACS UR W25 and ASTM B928, H116 and H321 plate for hulls is accepted only after showing resistance to exfoliation and intergranular corrosion.
| Test | Acceptance criterion |
|---|---|
| ASTM G66 (ASSET), exfoliation | No evidence of exfoliation; pitting rating PB or better |
| ASTM G67 (NAMLT), intergranular | Mass loss not more than 15 mg/cm² |
| Metallographic examination | Grain-boundary precipitation matches the approved reference micrograph at 500× |
These tests prove the plate leaves the mill in good condition. In service, avoid prolonged temperatures above about 65 °C, which can still sensitise 5083 over time. That is why exhaust trunks and hot tanks are designed in 5454 or insulated.
Standards, class rules and equivalents
| Standard or rule | Scope |
|---|---|
| ASTM B928 / B928M | High-magnesium marine plate and profiles with mandatory corrosion testing |
| ASTM B209 / ASME SB-209 | General sheet and plate; also used for pressure vessels |
| AMS-QQ-A-250/6 | 5083 plate for aerospace and defence orders |
| EN 485-1 / -2 / -3, EN 573-3 | European plate: delivery, properties, tolerances, composition |
| EN 13195 | Wrought and cast aluminium products for marine applications |
| IACS UR W25 and member-society rules | Hull material: approval, testing, branding and certification (ABS, BV, ClassNK, DNV, KR, LR, RINA and others) |
| JIS H4000 | Japanese plate (A5083P) |
| ISO 12215-5 | Small-craft scantlings, using the alloy's welded properties |
| System | 5083 | 5383 |
|---|---|---|
| Aluminum Association / ASTM | 5083 | 5383 |
| UNS | A95083 | A95383 |
| European (EN 573-3) | EN AW-5083 / AlMg4.5Mn0.7 | EN AW-5383 / AlMg4.5Mn0.9 |
| German Werkstoff | 3.3547 | — |
| ISO | AlMg4.5Mn0.7 | — |
| Japan (JIS) | A5083 | — |
| China (GB/T 3190) | 5083 | 5383 |
5083 plate sizes, weights and tolerances
Supply range
- Thickness
- Marine plate 3 – 50 mm; thicker plate to agreed standards
- Common sizes
- 1500 × 3000, 2000 × 6000 and 2000 × 8000 mm; other widths and lengths to order
- Imperial sizes
- 48 × 144, 60 × 144, 96 × 240 in; 3/16 – 2 in thick
- Surface
- Mill finish; PVC film or paper interleaving on request
- Processing
- Cutting to size, plate profiling and edge preparation on request
5083 weighs 2.66 kg per m² per millimetre of thickness, not 2.8 as sometimes quoted. Use the plate weight calculator for other sizes.
| Thickness (mm) | kg per m² | 1500 × 3000 mm (kg) | 2000 × 6000 mm (kg) |
|---|---|---|---|
| 3 | 7.98 | 35.9 | 96 |
| 4 | 10.64 | 47.9 | 128 |
| 5 | 13.30 | 59.9 | 160 |
| 6 | 15.96 | 71.8 | 192 |
| 8 | 21.28 | 95.8 | 255 |
| 10 | 26.60 | 119.7 | 319 |
| 12 | 31.92 | 143.6 | 383 |
| 15 | 39.90 | 179.6 | 479 |
| 20 | 53.20 | 239.4 | 638 |
| 25 | 66.50 | 299.2 | 798 |
| 30 | 79.80 | 359.1 | 958 |
| 40 | 106.40 | 478.8 | 1277 |
| 50 | 133.00 | 598.5 | 1596 |
Underthickness limits for class-certified plate follow UR W25 (below); other tolerances follow ASTM B209 / ANSI H35.2 or EN 485-3.
| Nominal thickness | Width ≤ 1500 mm | 1500 – 2000 mm | 2000 – 3500 mm |
|---|---|---|---|
| 3 – 4 mm | 0.10 mm | 0.15 mm | 0.15 mm |
| 4 – 8 mm | 0.20 mm | 0.20 mm | 0.25 mm |
| 8 – 12 mm | 0.25 mm | 0.25 mm | 0.25 mm |
| 12 – 20 mm | 0.35 mm | 0.40 mm | 0.50 mm |
| 20 – 50 mm | 0.45 mm | 0.50 mm | 0.65 mm |
Welding, forming and cutting 5083 plate
Welding
MIG and TIG with ER5183 filler, the standard for 5083 hulls. In the heat-affected zone strength falls to about the O-temper level (minimum yield 125 MPa), which class rules use for welded design.
Porosity control
Clean and brush joints just before welding, keep filler wire dry and sealed, and shelter welding from wind. Hydrogen from moisture and oil is the main cause of porosity.
Forming
H116 and H321 bend to moderate radii; allow for springback. For severe shapes, form in O or H111. Hot forming above about 200 °C should be avoided unless approved, because it can affect corrosion properties.
Cutting
Plasma, waterjet, saw and router cutting are all used. Dress back plasma-cut edges that will be welded.
Machining
Fair; the alloy is gummy. Sharp carbide, high rake and good coolant are needed. For machined tooling, cast and stress-relieved 5083 plate is a separate product.
Corrosion design
Isolate from steel and copper alloys, use aluminium-compatible antifouling, fit anodes and avoid crevices that trap water.
Where 5083 plate is used
- Hulls and decks of ferries, workboats, patrol craft, fishing vessels and yachts
- Superstructures on steel ships, joined with explosion-bonded transition joints
- Offshore accommodation modules, walkways and access structures
- LNG and cryogenic tanks in O temper, where toughness at −162 °C matters
- Pressure vessels to ASME SB-209 within the alloy's temperature limits
- Road and rail tankers, tipper bodies and transport structures
- Armour in specially processed tempers to military specifications
5083 compared with 5086, 5383 and 5059
| UR W25 minimum, 3 – 50 mm | 5086-H116 | 5083-H116 / H321 | 5383-H116 / H321 | 5059-H116 / H321 (≤ 20 mm) |
|---|---|---|---|---|
| Yield strength | 195 MPa | 215 MPa | 220 MPa | 270 MPa |
| Tensile strength | 275 MPa | 305 MPa | 305 MPa | 370 MPa |
| Annealed yield (welded approximation) | 95 MPa | 125 MPa | 145 MPa | 160 MPa |
| Availability | Good | Very good | Moderate | Made to order |
Choose 5086 for slightly easier forming at lower strength, 5383 or 5059 when the design takes advantage of higher welded strength, and 5083 for the best balance of strength, availability and cost. For non-structural interiors and small craft, 5052 or 5754 sheet may be enough.
How to order 5083 marine plate
- SpecifyAlloy and temper (5083-H116 or H321), thickness, plate sizes or nesting list, quantity, standard (ASTM B928, EN or class rules) and classification society.
- Confirm documentsWe confirm the mill approval, corrosion-test method, certificate type and any surveyor attendance before order.
- InspectDimensions, flatness, surface and plate branding checked against certificates.
- PackPlates interleaved and packed on seaworthy pallets or in cases, with lifting points for yard handling.
- ShipDelivered EXW, FOB, CIF or DAP to your port or yard, with certificates and packing list.
References and standards
- ASTM B928/B928M – High Magnesium Aluminum-Alloy Products for Marine Service and Similar Environments
- IACS Unified Requirement W25 – Aluminium alloys for hull construction and marine structure
- ASTM G66 (ASSET) and ASTM G67 (NAMLT) – exfoliation and intergranular corrosion tests for 5xxx alloys
- ASTM B209 – Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
- EN 485-2 – Aluminium and aluminium alloys: sheet, strip and plate, mechanical properties
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits (Teal Sheets)
5083 marine aluminium (aluminum) plate: FAQ
What is the difference between 5083-H116 and 5083-H321?
Both meet the same minimum strengths (yield 215 MPa, tensile 305 MPa) and must pass exfoliation and intergranular corrosion tests. H321 includes a final thermal stabilisation and has a controlled maximum strength; H116 is produced by controlled rolling. They are certified separately; order the one on the drawing.
Can I use 5083-H32 for a boat hull?
It is not recommended for class-built hulls. H32 lacks the corrosion-test controls of H116 and H321, and IACS UR W25 does not list it. It is fine for many industrial uses.
What is the density of 5083 aluminium?
2.66 g/cm³. A 2000 × 6000 × 10 mm plate weighs about 319 kg.
Which filler wire is used to weld 5083?
ER5183 is the standard filler for hulls. ER5356 can be used for lightly stressed joints. Avoid 4043 and 4047.
Is 5083 suitable for cryogenic tanks?
5083-O keeps its toughness at LNG temperatures and is widely used for cryogenic storage and transport tanks.
What is the maximum service temperature for 5083?
About 65 °C for sustained service. Longer exposure at higher temperatures can sensitise the alloy to intergranular corrosion.
Do you supply class-certified 5083 plate?
Yes, where the producing mill holds approval from the society you name. We confirm certificate type and corrosion testing before you order.
Building a hull in 5083?
Send thickness, sizes, temper, quantity and classification requirement. We will reply with availability, certificates and a delivered price.
