O / H111
Annealed (H111 has a slight strain from flattening). The most formable condition, used for discs that will be spun, pressed or dished into tank heads, and for parts that will be welded heavily.
Marine-grade round blanks
5083 Aluminium Circle, Disc and Round Plate
5083 aluminium circles are round blanks cut from 5083 sheet or plate, the aluminium-magnesium alloy specified for ships, pressure vessels and cryogenic tanks because it combines high non-heat-treatable strength with excellent seawater resistance and weldability. Metline supplies 5083 discs and round plates in O/H111, H116 and H321 tempers, cut to diameter from thin sheet up to heavy plate and certified to ASTM and EN standards, worldwide.
- Alloy
- 5083 (Al-4.5Mg-Mn)
- Tempers
- O/H111, H116, H321, H32
- Form
- Discs cut from sheet & plate
- Standards
- ASTM B209 · B928 · EN 485
What 5083 aluminium circles are used for
A 5083 circle is not a separate product so much as 5083 plate in a round shape. Buyers order discs when the finished part is round, such as a flange, tank head, hatch, valve body or machined end plate, so they pay for less scrap and less machining.
5083 contains about 4.5 % magnesium with manganese and chromium. It gains its strength from solid-solution hardening and cold work rather than heat treatment, so it keeps most of its strength after welding: in the O/H111 condition the weld zone is essentially as strong as the parent metal. It also resists seawater, marine atmospheres and many industrial chemicals, and it becomes stronger and tougher at cryogenic temperatures, which is why it is used for LNG tanks.
The main limitation is temperature. Alloys with more than about 3 % magnesium can become sensitised to intergranular corrosion and stress-corrosion cracking if held for long periods above roughly 65 °C. 5083 is therefore not recommended for parts that run hot in service, such as heater housings or cooking surfaces; 5754 or 5052 are safer choices there.
5083 chemical composition (wt %)
| Element | Minimum | Maximum |
|---|---|---|
| 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 |
Registered Aluminum Association limits, also used by ASTM B209 and EN 573-3 (EN AW-5083 / EN AW-AlMg4.5Mn0.7). The actual analysis of each lot is shown on the mill test certificate.
Mechanical properties by temper
| Temper | Tensile strength | Yield strength (0.2 %) | Elongation | Basis |
|---|---|---|---|---|
| O / H111 | 290 MPa | 145 MPa | 22 % | Typical |
| O / H111, sheet and plate | 275 – 350 MPa | ≥ 125 MPa | ≥ 11 – 16 % (by thickness) | EN 485-2 specified range |
| H116 / H321 | 317 MPa | 228 MPa | 16 % | Typical |
| H116 / H321, 4 – 40 mm | ≥ 305 MPa | ≥ 215 MPa | ≥ 10 – 12 % | ASTM B928 specified minimum |
Specified values depend on thickness band and are stated on the certificate. Typical values are for comparison only and are not design allowables.
Physical properties
- Density
- 2.66 g/cm³
- Melting range
- About 574 – 638 °C
- Modulus of elasticity
- 71 GPa
- Thermal conductivity
- About 117 – 121 W/m·K
- Electrical conductivity
- About 29 % IACS
- Coefficient of thermal expansion
- 23.8 µm/m·°C (20 – 100 °C)
Which temper to order
H116
Strain-hardened and tested for resistance to exfoliation and intergranular corrosion under ASTM G66 and G67, as ASTM B928 requires for marine hulls. Order H116 for discs going into ship structures.
H321
Strain-hardened and thermally stabilised. Similar strength to H116, also covered by ASTM B928 with the same corrosion tests when ordered for marine use.
H32 / H34
Quarter- and half-hard tempers for general engineering where a little more strength than H111 is wanted and marine corrosion testing is not required.
Standards and international equivalents
| System | Designation | Typical product standard |
|---|---|---|
| Aluminum Association / ASTM | 5083 | ASTM B209 (sheet and plate); ASTM B928 (marine H116/H321) |
| UNS | A95083 | — |
| European (EN) | EN AW-5083 / EN AW-AlMg4.5Mn0.7 | EN 485-1/-2, EN 573-3 |
| German Werkstoff | 3.3547 | DIN EN 485 |
| ISO | AlMg4.5Mn0.7 | ISO 6361 |
| Japan (JIS) | A5083P | JIS H4000 |
| China (GB) | 5083 | GB/T 3880 |
| India (IS) | 54300 | IS 736 |
For marine projects, classification societies such as DNV, ABS, Lloyd's Register and Bureau Veritas approve the producing mill and witness testing. If your discs must carry a class certificate, state the society on the enquiry so that material can be sourced and certified accordingly.
5083 circle sizes and weights
Supply range
- Thickness
- From about 0.5 mm sheet to heavy plate over 100 mm
- Diameter
- From small blanks up to the width of the parent plate; larger diameters to drawing
- Cutting method
- Shearing or punching for thin sheet; band saw, waterjet or CNC routing/plasma for plate
- Edge condition
- As cut, deburred, or machined to diameter on request
- Surface
- Mill finish, PVC film on one side, or precision-milled faces
- Rings and annular blanks
- Cut with a centre hole to save material on flange and ring parts
Tolerances on diameter are agreed per order; waterjet and CNC cutting hold tighter limits than sawing or shearing.
A 5083 disc weighs π/4 × D² × t × 2.66 g/cm³. The table gives approximate weights in kilograms; use the circle weight calculator for other sizes.
| Thickness (mm) | Ø 100 mm | Ø 200 mm | Ø 300 mm | Ø 500 mm | Ø 800 mm | Ø 1000 mm |
|---|---|---|---|---|---|---|
| 2 | 0.04 | 0.17 | 0.38 | 1.04 | 2.67 | 4.18 |
| 3 | 0.06 | 0.25 | 0.56 | 1.57 | 4.01 | 6.27 |
| 5 | 0.10 | 0.42 | 0.94 | 2.61 | 6.69 | 10.4 |
| 6 | 0.13 | 0.50 | 1.13 | 3.13 | 8.02 | 12.5 |
| 10 | 0.21 | 0.84 | 1.88 | 5.22 | 13.4 | 20.9 |
| 20 | 0.42 | 1.67 | 3.76 | 10.4 | 26.7 | 41.8 |
| 30 | 0.63 | 2.51 | 5.64 | 15.7 | 40.1 | 62.7 |
| 50 | 1.04 | 4.18 | 9.40 | 26.1 | 66.9 | 104.5 |
Machining, forming, welding and finishing
Machining
Softer tempers are gummy; use sharp, polished, high-rake carbide tools, high speeds and plenty of coolant. H116/H321 and stress-relieved cast 5083 tooling plate machine more cleanly.
Spinning and dishing
O/H111 discs can be spun or pressed into tank heads and domes. Allow for springback and work-hardening between stages.
Welding
MIG and TIG with ER5183 filler for the highest weld strength, or ER5356. The weld zone keeps close to O-temper strength, so welded structures are designed on annealed values.
Finishing
Anodises to a protective but slightly grey finish; paints and powder-coats well after proper pre-treatment. Often left bare in marine service.
Where 5083 discs are used
- Marine: hatch covers, deck fittings, flanges, portlight frames and bulkhead penetrations
- Pressure vessels and tanks: dished heads and end plates for road tankers, LNG and cryogenic vessels
- Process equipment: flanges and blind flanges for seawater and chemical piping
- Vacuum and semiconductor: chamber lids and end plates machined from stress-relieved 5083
- Defence and transport: welded structures where strength after welding is critical
5083 circles compared with other grades
| Property | 5083 H111 | 5052 H32 | 6061 T6 | 1050 / 3003 O |
|---|---|---|---|---|
| Typical tensile strength | 290 MPa | 230 MPa | 310 MPa | 75 – 110 MPa |
| Seawater resistance | Excellent | Very good | Fair | Good |
| Weld strength retained | High | High | Low (HAZ softens) | High |
| Deep drawing / spinning | Moderate | Good | Poor in T6 | Excellent |
| Typical disc use | Marine, pressure parts | General, marine fittings | Machined parts | Cookware, lighting, signs |
For cookware and lighting, a softer 1xxx or 3003 disc draws far better. For machined parts out of the water, 6061 is cheaper to machine. 5083 earns its place where strength, weldability and corrosion resistance all matter together.
How to order 5083 circles
- SpecifyAlloy and temper (e.g. 5083-H111 or 5083-H116), thickness, diameter, centre hole if any, tolerance and quantity, plus the governing standard.
- QuoteWe confirm cutting method, availability, certification and terms (EXW, FOB, CIF or DAP).
- Cut and inspectDiscs are cut, deburred, measured and protected with film or interleaving where needed.
- DocumentMill test certificate to EN 10204 3.1 with chemistry and mechanical results; class certificate where ordered.
- ShipDiscs stacked on pallets or in wooden cases with interleaving, shipped by sea or air.
References and standards
- ASTM B209 – Standard Specification for Aluminum and Aluminum-Alloy Sheet and Plate
- ASTM B928 – High Magnesium Aluminum-Alloy Sheet and Plate for Marine Service
- EN 485-2 – Aluminium and aluminium alloys: sheet, strip and plate, mechanical properties
- EN 573-3 – Chemical composition and form of wrought products
- The Aluminum Association – International Alloy Designations and Chemical Composition Limits
5083 aluminium (aluminum) circles: frequently asked questions
Is 5083 good for cookware discs?
No. 5083 is too strong to deep-draw easily and is not recommended for parts held above about 65 °C, where high-magnesium alloys can become sensitised. Use 1050, 1100 or 3003 circles for cookware.
What is the difference between 5083-H111 and 5083-H116 discs?
H111 is essentially annealed and best for forming and welding. H116 is strain-hardened for higher strength and is corrosion-tested under ASTM B928 for marine structures.
How heavy is a 5083 aluminium disc?
Weight = π/4 × diameter² × thickness × 2.66 g/cm³. A 500 mm disc 10 mm thick weighs about 5.2 kg; a 1000 mm disc 20 mm thick about 41.8 kg.
Can you cut 5083 rings with a centre hole?
Yes. Annular blanks save material on flanges and rings; send the outside and inside diameters and the tolerance on each.
Is 5083 weldable?
Yes, very. Use ER5183 or ER5356 filler. Strength in the weld zone stays close to the annealed value, so no post-weld heat treatment is needed.
Do you ship 5083 circles internationally?
Yes. Metline ships from Mumbai worldwide with mill certificates and export packing on EXW, FOB, CIF or DAP terms.
Need 5083 circles or discs?
Send diameter, thickness, temper, quantity and destination. We will confirm cutting method and certification and quote a delivered price.
