Aluminum Cast 5083
Cast 5083 is an Al-Mg4.5Mn alloy supplied as continuously/DC cast and stress-relieved thick plate rather than rolled plate, so it is nearly stress-free and holds flatness after heavy one-side machining.
Cast 5083 tempers and conditions
Cast 5083 is supplied in one standard condition, F.
What is Cast 5083?
Cast 5083 is an Al-Mg4.5Mn alloy supplied as continuously/DC cast and stress-relieved thick plate rather than rolled plate, so it is nearly stress-free and holds flatness after heavy one-side machining. It is chosen for large tooling plates, vacuum/marine fixtures and weldable machined bases where the seawater corrosion resistance of 5083 is needed together with dimensional stability. Strength and elongation are below rolled 5083-H116/H321 because of the as-cast grain structure and residual microporosity, and like all high-Mg 5000-series alloys it should not be used continuously above about 65 °C to avoid sensitisation and stress-corrosion cracking. Cast 5083 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 574°C (1,065 °F). Cast 5083 has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 77% of aluminum grades. Elongation at break is 12% and the elastic modulus is 71 GPa (10.3 Msi).
What is Cast 5083 used for?
- Thermoforming and vacuum forming mold plates
- Fixture and jig base plates
- Marine machined base and mounting plates
- Welded machined bases and frames
- Vacuum platens
- Inspection fixture plates
Advantages
- Low embodied carbon — 9.5 kg CO₂/kg, better than 97% of aluminum grades
- Good corrosion resistance — 75/100, better than 88% of aluminum grades
- Readily welded — 88/100, better than 85% of aluminum grades
Limitations
- Limited service temperature — 65°C (149 °F), worse than 97% of aluminum grades
- Poor heat conductor — 117 W/m·K (67.6 BTU/hr·ft·°F), worse than 83% of aluminum grades
- Low electrical conductivity — 29 % IACS, worse than 78% of aluminum grades
- Low strength — 120 MPa (17.4 ksi), worse than 77% of aluminum grades
- Hard to polish — 45/100, worse than 76% of aluminum grades
Cast 5083 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
Cast 5083 has a density of 2.66 g/cm³ (0.0961 lb/in³), lighter than 84% of aluminum grades. It melts at 574°C (1,065 °F).
Mechanical10
Cast 5083 has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 77% of aluminum grades. Elongation at break is 12% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
Cast 5083 is rated for continuous service to 65°C (149 °F). It conducts heat at 117 W/m·K (67.6 BTU/hr·ft·°F), worse than 83% of aluminum grades. Thermal expansion is 23.8 µm/m·K (13.2 µin/in·°F).
Electrical3
Cast 5083 conducts electricity at 29 % IACS, worse than 78% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is very good (75/100), better than 88% of aluminum grades.
Sustainability4
Producing a kilogram of Cast 5083 takes about 155 MJ of energy and emits 9.5 kg of CO₂ — less than 94% of aluminum grades. Typical recycled content is 45%.
Manufacturability8
Cast 5083's machinability is good (58/100, worse than 54% of aluminum grades); weldability excellent (88/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. Cast 5083 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Cast 5083
Is Cast 5083 easy to machine?
Machines cleanly and with very little distortion because the plate is essentially stress-free; use sharp polished-flute carbide, high speed, generous coolant to avoid gummy build-up on the Mg-rich matrix.
Can Cast 5083 be welded?
Excellent GMAW/GTAW weldability with 5183 or 5356 filler; no post-weld heat treatment, but expect weld-zone strength near O-temper and keep interpass temperature low.
Can Cast 5083 be formed, bent or molded?
Not a forming grade — supplied as thick cast plate for machining; bending or deep drawing should use rolled 5083-O/H sheet instead.
Manufacturability
The process limits FabDigit applies to Cast 5083. Every Cast 5083 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Better58 / 100 |
|---|---|
| ISO material group | N.3 |
| Cutting speed (rough / finish) | 200 / 250 m/min |
| Minimum wall | 1 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
Cast 5083 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Si | ≤ 0.4 | 0.2 |
| Fe | ≤ 0.4 | 0.25 |
| Cu | ≤ 0.1 | 0.03 |
| Mn | 0.4 – 1 | 0.7 |
| Mgprincipal strengthening element | 4 – 4.9 | 4.45 |
| Cr | 0.05 – 0.25 | 0.12 |
| Zn | ≤ 0.25 | 0.05 |
| Tigrain refiner in cast plate | ≤ 0.15 | 0.03 |
| Others (each)0.15 total | ≤ 0.05 | |
| Al | balance |
What surface finishes work on Cast 5083?
Clear and hard anodizing are practical though the cast structure may look slightly mottled; not brazeable/solderable, and paint or powder coat over a chromate-free conversion coat gives the best marine appearance.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Conversion Coating
PVD Coating
How much does Cast 5083 cost?
Cast 5083 is a premium-cost aluminum ($$$), cheaper than about 62% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Cast 5083 — frequently asked
What is Cast 5083 used for?
Cast 5083 is typically used for thermoforming and vacuum forming mold plates, fixture and jig base plates, marine machined base and mounting plates, welded machined bases and frames, vacuum platens and inspection fixture plates. In short: precision flat; stable cast plate.
What is the yield strength of Cast 5083?
Cast 5083 has a typical yield strength of 120 MPa (17.4 ksi) and a tensile strength of 260 MPa (37.7 ksi) — weaker than 77% of aluminum grades.
Is Cast 5083 easy to machine?
Reasonably — machinability is rated good (58/100, worse than 54% of aluminum grades). Machines cleanly and with very little distortion because the plate is essentially stress-free; use sharp polished-flute carbide, high speed, generous coolant to avoid gummy build-up on the Mg-rich matrix.
Can Cast 5083 be welded?
Yes — weldability is rated excellent (88/100). Excellent GMAW/GTAW weldability with 5183 or 5356 filler; no post-weld heat treatment, but expect weld-zone strength near O-temper and keep interpass temperature low.
What surface finishes work on Cast 5083?
Clear and hard anodizing are practical though the cast structure may look slightly mottled; not brazeable/solderable, and paint or powder coat over a chromate-free conversion coat gives the best marine appearance.
Can Cast 5083 be formed, bent or molded?
Not a forming grade — supplied as thick cast plate for machining; bending or deep drawing should use rolled 5083-O/H sheet instead.
What is the maximum service temperature of Cast 5083?
Cast 5083 is rated for continuous use to about 65°C (149 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does Cast 5083 cost?
Cast 5083 is a premium-cost aluminum ($$$), cheaper than about 62% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in Cast 5083?
Yes — Cast 5083 is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- Aluminum Association Teal Sheets — International Alloy Designations and Chemical Composition Limits for Wrought Aluminum — The Aluminum Association (2018)
- ASTM B209 / B928 — Aluminum Alloy Plate and Sheet, High-Magnesium Marine Alloys — ASTM International (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- Cast aluminium tooling plate (5083-type, ALCA 5 class) technical data — Vista Metals / Alimex (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.