Aluminum 5083: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

5083 is part of the 5xxx series of wrought aluminum alloys, characterized by magnesium as the principal alloying element. It is a non-heat-treatable, strain-hardened alloy that derives its strength primarily from solid-solution strengthening by magnesium and from work-hardening during fabrication.

The major alloying constituents are magnesium (nominally around 4–4.9%) with minor manganese and chromium additions that refine grain structure and improve strength and corrosion resistance. Typical traits include a high strength-to-weight ratio for a non-heat-treatable alloy, excellent resistance to seawater and marine atmospheres, good weldability, and fair formability depending on temper and thickness.

Industries that most commonly specify 5083 include shipbuilding and marine structures, cryogenic tanks, pressure vessels, heavy-duty transportation, and some automotive and aerospace fittings where corrosion resistance and damage tolerance are prioritized. Engineers select 5083 where a combination of high ambient and saltwater corrosion resistance, moderate-to-high strength, and excellent weldability outweighs the need for the higher peak strengths available from heat-treatable alloys.

Compared with other aluminum families, 5083 is chosen when long-term environmental durability and toughness are critical. It is preferred over many 6xxx and 7xxx alloys for welded, large-scale structures in marine or cryogenic service because it does not suffer the same kind of weld-zone embrittlement or significant loss of corrosion resistance after welding.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed, maximum ductility for forming
H111	Low-Medium	High	Very Good	Excellent	Minimal work-hardening from production, general-purpose
H112	Medium	Moderate	Good	Excellent	Standard commercial strain-hardened condition
H32	Medium-High	Moderate	Fair	Excellent	Strain-hardened and stabilized; higher retained strength
H116	Medium-High	Moderate	Fair	Excellent	Stabilized for improved resistance to exfoliation corrosion in marine service
H321	Medium	Moderate	Good	Excellent	Stabilized by anti-precipitation treatment to control grain boundary phases

Tempering in 5083 is accomplished by mechanical working (H-series) or by annealing (O). The choice of temper sets the balance between strength and ductility: more cold work increases yield and tensile strength while reducing elongation and formability, and stabilizing tempers (H116/H321) trade some ductility for improved corrosion resistance in aggressive environments.

Temper selection also influences forming and post-weld performance since strain-hardened tempers can be partially softened by elevated temperatures in welding or by limited annealing, altering local mechanical properties and residual stress distribution.

Chemical Composition

Element	% Range	Notes
Si	≤ 0.40	Impurity that can form brittle intermetallics if excessive
Fe	≤ 0.40	Strength contribution minimal; excessive Fe reduces corrosion resistance
Mn	0.40–1.00	Grain refinement and strength, aids resistance to recrystallization
Mg	4.0–4.9	Principal strengthening element, provides solid-solution strengthening and corrosion resistance
Cu	≤ 0.10	Kept low to preserve corrosion resistance, small amounts can raise strength
Zn	≤ 0.25	Minor impurity; higher Zn is avoided to limit susceptibility to stress corrosion
Cr	0.05–0.25	Controls grain structure, improves strength and corrosion resistance after thermo-mechanical processing
Ti	≤ 0.15	Grain refiner in small amounts during casting and ingot production
Others	Balance Al; trace B, Zr possible	Aluminum balance; trace microalloying can be present to tailor properties

Magnesium is the key performance driver: it increases tensile and yield strength through solution strengthening and also promotes resistance to seawater corrosion by stabilizing the oxide film. Manganese and chromium are added to stabilize grain structure during rolling and heat exposure, which enhances toughness and impedes recrystallization. Low copper and controlled iron/silicon maintain galvanic and pitting resistance crucial for marine applications.

Mechanical Properties

5083 exhibits ductile tensile behavior with notable strain hardening; in the annealed state the material yields at relatively low stress but can accept large plastic strains, while in strain-hardened tempers the yield and tensile strengths rise substantially at the cost of elongation. Hardness correlates with temper: annealed O is the softest and most formable, while H32/H116 will show higher Brinell/Vickers hardness values consistent with elevated yield strength. Fatigue performance is generally good for a non-heat-treatable alloy because of the ductility and resistance to crack propagation, but fatigue life is sensitive to surface finish, weld quality, and residual tensile surface stresses.

Thickness has a pronounced effect: thin-gage sheet typically attains higher apparent strength due to rolling-induced texture, while thick plate can be softer and show lower elongation; thicker sections also require more careful control of quench and post-weld cooling to avoid HAZ softening or residual stress concentration. Welded structures retain good static strength but localized heat affected zones may exhibit reduced yield strength relative to the parent material depending on temper and joint design; appropriate filler selection and weld procedures mitigate common issues.

For design data it is customary to reference tensile and yield ranges rather than single values because results vary with temper, thickness, and processing route. Engineers must consult supplier mill certificates and relevant standards for exact allowable design strengths for structural calculations and safety factors.

Property	O/Annealed	Key Temper (e.g., H116/H32)	Notes
Tensile Strength (MPa)	220–270	320–370	Values depend on thickness and cold work; H116/H32 are common structural tempers
Yield Strength (MPa)	35–90	200–260	Annealed YS is low; H tempers show substantial increase in yield
Elongation (%)	20–30	10–16	Annealed shows high ductility; strain-hardened tempers reduced elongation
Hardness (HB)	~30–50	~70–95	Approximate ranges; hardness increases with cold work and alloy stabilization

Physical Properties

Property	Value	Notes
Density	2.66 g/cm³	Lower than steel; good strength-to-weight ratio for structural applications
Melting Range	~570–645 °C	Alloyed melting range below pure Al's melting point peak, solidus-liquidus range varies with impurities
Thermal Conductivity	~110–125 W/m·K (20 °C)	High thermal conductivity compared with steels, useful for heat dissipation
Electrical Conductivity	~30–38 % IACS	Lower than pure aluminum due to alloying; adequate for some electrical applications
Specific Heat	~900 J/kg·K	Typical for aluminum alloys near room temperature
Thermal Expansion	~23.5 ×10⁻⁶ /K	High thermal expansion; thermal cycling needs consideration in assemblies with dissimilar materials

The relatively high thermal conductivity and low density of 5083 make it attractive where heat dissipation and lightweight design are needed, such as heat exchangers and vehicle structures. The thermal expansion coefficient is large compared with steels, so differential thermal strain and joint design must be considered for mixed-metal assemblies.

Melting and softening behavior dictate welding procedures and thermal processing windows; processing above roughly 200–300 °C can affect strain-hardened tempers by partial recovery and softening, so thermal exposures must be controlled to preserve in-service properties.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.5–6 mm	Higher apparent strength due to cold rolling	O, H111, H32, H116	Widely available; used for hull plating, panels, and enclosures
Plate	6–200 mm	May be softer in thick sections; strength depends on rolling route	H116, H32, H112	Heavy plating for ship hulls, pressure vessels, and cryogenic tanks
Extrusion	Complex profiles, up to several meters	Strength varies with section thickness and aging	H111, H112	Structural profiles and stiffeners; careful control of extrusion temperature required
Tube	OD and wall variable	Good pressure resistance when cold-worked	O, H111	Heat exchangers and marine piping; weld-seam quality critical
Bar/Rod	Diameter dependent	Uniform strength; machinability moderate	O, H111	Fittings, fasteners, and machined components

Sheets and plates are produced with differing rolling schedules and solution treatment histories; sheet is typically cold-rolled to tight tolerances, which introduces texture and influences forming and anisotropy. Extrusions and bars derive strength and microstructure from hot-working and subsequent cooling; profile thickness variations yield local differences in mechanical properties that must be accounted for in design.

Processing differences govern selection: for example, plate for shipbuilding is often supplied in H116 to guarantee corrosion resistance and improved strength retention after welding, while sheet for complex stamping operations is usually supplied in O or light H tempers to maximize formability.

Equivalent Grades

Standard	Grade	Region	Notes
AA	5083	USA	Common Aluminum Association designation used in North America
EN AW	5083	Europe	EN AW-5083 correlates with AA 5083; European specs emphasize exfoliation corrosion classes
JIS	A5083	Japan	JIS designation aligns closely but may have different impurity limits and testing practices
GB/T	5083	China	Chinese standard uses similar numeric designation but composition/tolerance differences may exist

Subtle differences between standards can impact allowable impurity limits, testing methods, and qualification of tempers and product forms. Buyers should confirm that mill certificates comply with the specific regional specification and any project-specific material requirements, especially for critical marine or cryogenic applications where exfoliation corrosion or toughness acceptance criteria differ.

Corrosion Resistance

5083 demonstrates excellent atmospheric corrosion resistance and is particularly well suited to marine environments because the Mg-rich matrix forms a protective, adherent oxide film. In seawater and splash zones, the alloy resists pitting and general corrosion markedly better than many heat-treatable 6xxx and 7xxx alloys, provided copper and zinc contents are kept low and appropriate tempers (e.g., H116) are used.

Stress corrosion cracking (SCC) susceptibility is much lower in 5083 than in high-strength, heat-treatable alloys, but localized SCC can still occur under high tensile stresses and certain environmental chemistries. Galvanic behavior is favorable compared with stainless steels and copper alloys due to its relatively noble potential among aluminum alloys, but designers must still avoid direct contact with more cathodic materials without insulation and drainage considerations.

Compared to 3xxx series work-hardened alloys, 5083 offers improved strength and comparable corrosion resistance; compared to 6xxx series heat-treatable alloys, 5083 typically provides superior long-term marine corrosion resistance at the expense of achievable peak strength. Surface treatments, anodizing, and protective coatings are commonly applied when additional corrosion protection or cosmetic finishes are required.

Fabrication Properties

Weldability

5083 is highly weldable by common fusion processes including MIG (GMAW), TIG (GTAW), and submerged arc welding, and it responds well to weld procedures when proper joint fit-up, cleaning, and pre/post-weld practices are employed. Recommended filler alloys are usually 5356 (Al–Mg) for good strength and corrosion resistance in the weld metal; 5183 filler is another option for heavy-section and critical marine welds where matching properties are required.

Hot-cracking risk is low relative to high-copper aluminum alloys, but porosity and weld defect control are still necessary; contamination and excessive oxide films increase porosity incidence. Heat-affected zone (HAZ) softening can occur in strain-hardened parent metal when peak weld temperatures locally anneal the region; design and sequence of welding passes, as well as post-weld mechanical treatments, mitigate distortion and strength loss.

Machinability

5083 has moderate machinability; it machines less easily than pure aluminum and some other wrought alloys due to its higher strength and work-hardening tendency. Tooling should be high-positive geometry carbide cutters or coated high-speed steel, and cutting speeds are typically lower than for 6xxx series alloys to avoid work-hardening of the chip and tool adhesion.

Chip control can be challenging on thin-wall sections; use of sharp tools, effective lubrication/coolant, and controlled feed rates produce acceptable surface finish and dimensional control. Accuracy and finish degrade with increasing Mg content and with temper-induced anisotropy, so allowances and machining trials are recommended for critical components.

Formability

Formability is highly temper- and thickness-dependent; fully annealed O temper offers excellent stretch and draw formability, while H32/H116 temper reduces formability and demands larger bend radii. Minimum bend radii depend on sheet thickness and temper but are typically larger than for more ductile 1xxx or 3xxx alloys; springback must be anticipated and included in tooling compensation.

Cold working raises strength through strain hardening, enabling components to be formed then used in higher-strength condition, but successive forming operations and local heating (e.g., from welding) can produce uneven mechanical properties. Warm forming and incremental forming techniques can extend formability for complex shapes without full annealing.

Heat Treatment Behavior

5083 is a non-heat-treatable alloy where strength is produced primarily by solid-solution alloying and by cold work rather than by precipitation hardening. Thermal treatments aimed at solutionizing and artificial aging used on 6xxx/7xxx series are ineffective here because the Mg is in solid solution and does not precipitate into strengthening phases that respond to aging.

Annealing (softening) is achieved by heating into the recovery/recrystallization range, typically between 300 °C and 400 °C for times depending on section thickness, which reduces dislocation density and restores ductility. Cold work (rolling, bending) is used to increase yield and tensile strength through dislocation accumulation; stabilizing operations and controlled natural aging steps may be used to optimize corrosion resistance and to minimize strain-induced exfoliation.

Tempers such as H116 incorporate sequences that limit susceptibility to exfoliation corrosion by controlling grain boundary precipitates and may include controlled solution and natural aging steps during mill processing. Designers must recognize that welding exposes local zones to thermal cycles that behave as localized anneals and can change mechanical properties and corrosion behavior.

High-Temperature Performance

At elevated temperatures the mechanical strength of 5083 falls off significantly compared with room-temperature values; above ~150–200 °C the alloy experiences marked softening and reduced yield capacity. Sustained high-temperature exposure reduces creep resistance and increases susceptibility to microstructural recovery; therefore continuous service temperatures are typically limited well below 200 °C for load-bearing applications.

Oxidation is minor compared with steels because aluminium forms a protective oxide, but prolonged exposure at high temperatures can alter surface chemistry and accelerate grain boundary processes that may reduce toughness. In welded assemblies, the HAZ can become a focal point for strength loss at elevated service temperatures, so design margins and thermal management must account for localized softening.

Applications

Industry	Example Component	Why 5083 Is Used
Marine	Hull plating, superstructure, bulkheads	Excellent seawater corrosion resistance and good strength-to-weight for large welded structures
Automotive/Transport	Trailers, tanker panels, structural frames	Toughness, weldability, and damage tolerance for heavy-duty applications
Aerospace	Secondary structures, fittings	High specific strength and good fatigue resistance for non-primary structural items
Cryogenics	LNG tanks, cryogenic vessels	Retains toughness at low temperatures and resists stress corrosion in cryogenic environments
Energy/Pressure Vessels	Pressure cylinders and heat exchangers	Good weldability and corrosion resistance for contained fluids

5083 is selected for components where a robust combination of corrosion resistance, weldability, and toughness is required, particularly in large welded structures and cryogenic applications. Its reliability under cyclic loading and in aggressive environments has made it a staple material for shipbuilders and industries requiring long-lived, low-maintenance metallic structures.

Selection Insights

Choose 5083 when corrosion resistance in marine or chemically aggressive atmospheres and good weldability are design drivers, and when moderate-to-high strength without heat treatment is acceptable. It is a strong choice for welded structures, cryogenic tanks, and transport bodies where long-term durability is more important than the absolute peak strength.

Compared with commercially pure aluminum like 1100, 5083 trades higher strength and improved fatigue resistance for a small reduction in electrical and thermal conductivity and slightly reduced formability. Compared with work-hardened alloys such as 3003 or 5052, 5083 usually offers higher strength and comparable or better marine corrosion resistance, at modestly higher material cost. Compared with heat-treatable alloys like 6061 and 6063, 5083 provides superior corrosion resistance and weld-zone performance for marine and cryogenic uses, though it cannot reach the peak strengths that precipitation-hardened alloys deliver.

In procurement, balance availability and cost against service environment: if marine exposure and weld quality are key, favor 5083 (H116 for marine); if maximum lightness and highest yield/tensile are needed and welding is limited, consider heat-treatable 6xxx or 7xxx alternatives.

Closing Summary

5083 remains highly relevant due to its unique combination of Mg-based solid-solution strength, excellent seawater corrosion resistance, and robust weldability, making it a go-to material for marine, cryogenic, and heavy structural applications where longevity and damage tolerance are priorities.