5083 aluminum flat bar (AlMg4.5Mn0.7) is a marine-grade, non-heat-treatable bar stock prized for seawater corrosion resistance, excellent weldability, and high strength in strain-hardened tempers. Linsy supplies it in O, H111, H116, and H321 for shipbuilding, pressure vessels, and offshore structures.
Available forms: flat bar
Common tempers: O / H111 / H116 / H321
Processing support: sawing / CNC machining / laser cutting / anodizing / polishing
Quality documents: MTC report with every order
5083 flat bar is a rectangular-section, marine-grade aluminum bar made from the non-heat-treatable 5xxx alloy 5083 (AlMg4.5Mn0.7). It combines high magnesium content with manganese for strength, giving it outstanding resistance to seawater and industrial-chemical corrosion plus excellent weldability.
Because 5083 does not soften in the heat-affected zone of a weld, flat bar in marine tempers (H116, H321) is widely used for structural members that must be welded and then perform in harsh environments.
Linsy supplies 5083 flat bar in the size ranges below; other widths, thicknesses, and lengths are available on request.
| Temper | Thickness (mm) | Width (mm) | Length (mm) |
|---|---|---|---|
| O, H111, H116, H321 | 3 – 120 | 12 – 400 | 1000 – 6000 |
Standard and custom lengths are cut from our stock; closer tolerances and edge preparation can be arranged with our machining service.
5083 flat bar maps to the following designations:
Bar and profile supply typically follows ASTM B221 and EN 755; marine applications may reference ASTM B928 for plate equivalents and classification-society rules.
Typical composition of 5083 (per ASTM/EN), percentage by weight; aluminum is the balance:
| Element | Content (%) |
|---|---|
| Silicon (Si) | 0.40 max |
| Iron (Fe) | 0.40 max |
| Copper (Cu) | 0.10 max |
| Manganese (Mn) | 0.40 – 1.00 |
| Magnesium (Mg) | 4.00 – 4.90 |
| Chromium (Cr) | 0.05 – 0.25 |
| Zinc (Zn) | 0.25 max |
| Titanium (Ti) | 0.15 max |
| Others (each) | 0.05 max |
| Others (total) | 0.15 max |
| Aluminum (Al) | Balance |
Typical room-temperature properties for 5083 flat bar. Values are indicative and vary with thickness and specification; confirm against the MTC for your order.
| Temper | Tensile strength (MPa) | Yield strength (MPa) | Elongation (%) | Brinell hardness (HB) |
|---|---|---|---|---|
| O | 275 | 125 | 16 | 75 |
| H111 | 290 | 165 | 14 | 80 |
| H116 | 305 | 215 | 12 | 95 |
| H321 | 305 | 215 | 12 | 95 |
5083 performs exceptionally well in marine and industrial environments. Its high magnesium content gives it strong resistance to pitting and general corrosion in seawater, making it a standard choice for hulls, superstructures, and offshore platforms.
As a non-heat-treatable alloy, 5083 retains most of its strength after welding and does not suffer from heat-affected-zone softening the way heat-treatable grades do. It is readily weldable by TIG and MIG processes; 5xxx filler wires such as 5183 or 5356 are typically used.
Among work-hardened aluminum alloys, 5083 offers one of the highest strength levels while keeping good ductility. Strain-hardened tempers (H116, H321, H32) raise yield strength without sacrificing too much formability.
5083 maintains toughness at very low temperatures and does not become brittle when cold, which is why it is widely used for LNG tanks and cryogenic pressure vessels.
Tempers such as H116 and H321 are specified for marine service because they offer improved resistance to exfoliation and stress corrosion cracking compared with general-purpose tempers.
Every 5083 order from Linsy ships with a Mill Test Certificate (MTC) that reports the heat number, chemical analysis, mechanical test results, and the applicable standard. Third-party inspection and SGS test reports are available on request.
Our production follows ISO 9001 (quality), ISO 14001 (environment), and ISO 45001 (occupational health and safety) management systems. Dimensional and visual inspection is carried out against ASTM, EN, or GB specifications as required by the order.
Linsy Aluminum is a Shenzhen-based aluminum manufacturer with more than 20 years of experience supplying plate, bar, tube, wire, coil, and profile across the 1000 to 8000 series.
We stock and process 5083 in the marine tempers buyers actually need (O, H111, H116, H321) and provide MTC documentation with every shipment so your project passes classification and weld-procedure requirements.
In addition to supplying mill forms, we offer CNC machining, laser cutting, sawing, and surface finishing (anodizing, polishing, mill finish, powder coating, PVC film protection) to deliver closer-to-final parts.
Typical custom lead time is 10-60 days depending on temper, size, and quantity. Small trial orders and low MOQs are supported for new projects.
No. 5083 is non-heat-treatable and is supplied in annealed (O) or strain-hardened (H) tempers only.
H116 or H321 are the usual marine choices because they offer good strength with improved resistance to stress corrosion cracking. O or H111 are better when extensive forming is required first.
Yes. We cut to length and can machine, drill, or laser-cut flat bar to drawing. MTC is provided with every order.
5xxx fillers matched to the base alloy, typically 5183 or 5356, depending on joint and performance requirements.
Typical custom lead time is 10-60 days, depending on the temper, size, and order quantity. Stock tempers can usually ship faster.
Yes. Every order ships with an MTC that reports chemistry, mechanical properties, and the applicable standard. SGS or third-party inspection reports are available on request.
We support low MOQs for prototypes and trial runs. Exact minimums depend on the form and size, so please share your requirement for a quote.
We export worldwide. Contact us with your delivery port and we will confirm logistics and documentation.
Yes. We provide sawing, laser cutting, and CNC machining, as well as surface finishing such as anodizing and polishing.
Linsy Advantages
Linsy Aluminum is a leading supplier of aluminum processing products, serving diverse industries including aerospace, general engineering, automotive, marine, shipbuilding and other specialized industrial applications.
We are committed to maintaining the highest standards of quality and environmental responsibility, as demonstrated by our certifications: ISO 9001:2008， ISO 14001:2004 and SGS.
