Aluminum EN AW-5083: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

EN AW-5083 is a member of the 5xxx series aluminum alloys, characterized primarily by magnesium as the principal alloying addition. The designation indicates a non-heat-treatable, wrought alloy in the Al-Mg-Mn system that is optimized for a combination of strength and corrosion resistance.

Strength in 5083 is principally achieved by solid-solution strengthening from magnesium and by strain hardening where applicable; it is not a precipitation-heat-treatable alloy. The alloy exhibits a favorable balance of moderate-to-high strength, excellent resistance to seawater and industrial atmospheres, good weldability, and reasonable formability, which makes it a workhorse in demanding structural applications.

Typical industries using EN AW-5083 include marine and shipbuilding, pressure vessels, cryogenic tanks, structural plate for rolling stock, and certain automotive and aerospace fittings. Engineers select 5083 when a higher strength-to-weight ratio than pure aluminum is needed together with superior corrosion performance in chloride-rich environments.

Compared with other aluminum families, 5083 offers a superior marine corrosion resistance and weldability versus 6xxx or 7xxx series alloys, while trading off peak heat-treatable strength for robustness and damage tolerance under cyclic loading and impact.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed, maximum ductility, used for deep drawing and forming
H111	Low–Medium	High	Very Good	Excellent	Slightly strain-hardened but not stable; often a mill-finish temper
H112	Low–Medium	High	Very Good	Excellent	Designation for product forms with unspecified straightening; similar to H111
H116	Medium	Medium	Good	Excellent	Stabilized temper for improved exfoliation corrosion resistance in marine use
H321	Medium	Medium	Good	Excellent	Strain-hardened and stabilized by trace titanium additions to resist sensitization
H32	Medium–High	Medium	Fair	Excellent	Strain-hardened (work-strengthened) then partially annealed by natural aging
T351	Medium–High	Medium	Fair	Excellent	Solution treated, stress-relieved by stretching and naturally aged; used for plate

Temper has a significant effect on mechanical performance and formability of 5083. Annealed O temper maximizes ductility for forming operations, while H- and T-tempers raise strength through mechanical strain or controlled thermal processes at the cost of some elongation.

For welded structures, stabilized tempers (H116, H321) are selected to minimize susceptibility to exfoliation and intergranular corrosion after welding; the choice of temper is therefore a trade-off between forming ease, as-delivered strength, and long-term corrosion behavior.

Chemical Composition

Element	% Range	Notes
Si	≤ 0.40	Controlled to minimize intermetallics and retain ductility
Fe	≤ 0.40	Impurity element that forms intermetallics affecting toughness
Mn	0.40–1.00	Promotes grain structure control and strength via dispersion
Mg	4.0–4.9	Primary strengthening element; improves corrosion resistance in chloride environments
Cu	≤ 0.10	Kept low to preserve corrosion resistance and weldability
Zn	≤ 0.25	Low levels to avoid susceptibility to stress corrosion
Cr	0.05–0.25	Grain refiner and recrystallization inhibitor; improves strength and stress-corrosion resistance
Ti	≤ 0.15	Trace additions used in some tempers to control grain size
Others	≤ 0.15 total	Includes V, Zr, etc.; kept minimal to meet specifications

The relatively high Mg content is the dominant factor in 5083’s mechanical and corrosion behavior; it increases solid-solution strengthening and enhances resistance to seawater attack. Manganese and chromium refine the microstructure and inhibit recrystallization, improving strength and resistance to exfoliation corrosion, especially in thicker sections.

Tight control of iron and silicon is important because intermetallic phases rich in these elements can act as crack initiation sites and reduce toughness and fatigue resistance.

Mechanical Properties

Tensile behavior of EN AW-5083 is characterized by good ductility in annealed conditions and a substantial increase in strength with work hardening or stabilized tempers. Yield and ultimate strengths scale with temper and also with section thickness and processing history; thicker plates generally show slightly reduced yield due to microstructural heterogeneity. Fatigue performance is favorable compared with many heat-treatable alloys because 5083 retains toughness and resistance to crack propagation even when cold-worked or welded.

Elongation values are highest in the O temper and decrease with increasing strain-hardening or stabilization. Hardness tracks strength changes and serves as a convenient shop-floor proxy for temper verification, but hardness values must be interpreted alongside tensile testing for design-critical applications. Welding creates a heat-affected zone (HAZ) with some degree of softening depending on initial temper, but overall joint performance is good when appropriate filler metals and techniques are used.

Property	O/Annealed	Key Temper (H32 / H116 / T351)	Notes
Tensile Strength (MPa)	Typical 210–270	Typical 300–370	Values depend on exact temper, thickness, and supplier; plate often on higher end
Yield Strength (MPa)	Typical 70–120	Typical 190–260	H-tempers increase yield substantially due to strain hardening/stabilization
Elongation (%)	Typical 18–28	Typical 8–18	Annealed condition gives maximum elongation; H-tempers reduce ductility
Hardness (HB)	Typical 35–60	Typical 60–95	Hardness correlates with yield; used for production QC

Physical Properties

Property	Value	Notes
Density	2.66 g/cm³	Typical density for Al-Mg alloys; useful for mass and stiffness calculations
Melting Range	~555–650 °C	Solidus–liquidus range varies with composition and impurities
Thermal Conductivity	~120–135 W/m·K	Lower than pure Al but still high; useful for thermal management applications
Electrical Conductivity	~34–38 %IACS	Reduced relative to pure Al due to Mg and alloying additions
Specific Heat	~880–910 J/kg·K	Typical aluminum-class specific heat used in thermal design
Thermal Expansion	~23–24 µm/m·K (20–100 °C)	Moderately high coefficient, important for joint and thermal stress design

Thermal and electrical conductivities are lower than pure aluminum because of solid-solution scattering from magnesium and other solutes, but values remain favorable for heat-sinking and current-carrying applications where mechanical performance is also required. The moderate density and high thermal conductivity make 5083 attractive where lightweight thermal structural components are needed.

Designers should account for relatively high thermal expansion in multi-material assemblies; differential expansion with steels or composites can drive stresses in cyclic temperature environments.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.5–6 mm	Uniform, good formability	O, H111, H32	Used for hull panels, bodywork, and formed components
Plate	6–200+ mm	Strength can vary through thickness; thicker sections often H116/H321	H116, T351, H32	Structural plate for shipbuilding and pressure vessels
Extrusion	Profiles up to large cross-sections	Strength depends on section and cooling; workability depends on magnesium content	H32, H321	Used for stiffeners, rails, and fabricated frames
Tube	Ø small to large, various wall thicknesses	Similar to sheet; welded or seamless options	O, H111, H32	Common in pressure tubing and marine piping
Bar/Rod	Up to large diameters	Typically supplied in strain-hardened tempers for strength	H111, H32	Used for machined fittings and fasteners where corrosion resistance is needed

Processing differences between sheet and plate are significant: plate production (especially thick plate) requires slower cooling and more careful control of grain structure to avoid exfoliation and to maintain toughness. Extrusions require attention to die design and quench conditions to control residual stresses and dimensional stability.

Application selection should consider that very thick sections may require stabilized tempers to mitigate exfoliation and intergranular corrosion; thin sheet in O-temper will allow complex forming but will subsequently need work-hardening or tempering to reach required service strength.

Equivalent Grades

Standard	Grade	Region	Notes
AA	5083	International (Aluminum Association)	Widely used US designation; compositions align closely with EN version
EN AW	5083	Europe	EN AW-5083 is the common European marking consistent with EN standards
JIS	A5083 (approx.)	Japan	Rough cross-reference; verify local JIS specifications for exact composition and tempers
GB/T	5083 (approx.)	China	Chinese standards commonly reference 5083 series but check local grade variants and control limits

Cross-references exist between standards, but subtle differences in impurity limits and permitted tempers can affect performance in specialty applications. Certification and material test reports (MTRs) should be checked for each order to ensure composition, mechanical properties, and tempering meet the design requirements in the target standard.

Manufacturers sometimes apply proprietary designations for stabilized or low-exfoliation variants; when substituting, validate both chemistry and controlled processing (e.g., solution treatment, stabilizing heat treatments) rather than relying solely on grade name.

Corrosion Resistance

EN AW-5083 shows excellent atmospheric corrosion resistance and is a preferred alloy for marine and offshore applications due to its resistance to pitting and crevice corrosion in chloride-rich environments. The high Mg content improves natural film formation, while small additions of Cr and Mn help suppress localized exfoliation in thicker sections.

In seawater and splash-zone service, 5083 performs substantially better than many heat-treatable alloys because it resists intergranular attack following welding when appropriate tempers (H116/H321) are used. However, under certain metallurgical conditions and tensile stresses, 5xxx alloys can be susceptible to stress-corrosion cracking (SCC); 5083 has relatively good SCC resistance compared with other Mg-rich alloys but design must still minimize sustained tensile stresses in corrosive environments.

Galvanic interactions should be considered when mating 5083 to other metals: it is anodic to stainless steel and cathodic to common ferrous alloys, so insulating barriers or sacrificial anodes may be required in marine assemblies. Compared with 6xxx and 7xxx series alloys, 5083 offers superior chloride resistance but lower peak hardness and strength than heat-treatable alloys.

Fabrication Properties

Weldability

EN AW-5083 is highly weldable using common fusion processes such as TIG (GTAW), MIG (GMAW), and submerged arc welding (SAW). Recommended filler alloys include 5356 or 5183 for most welds; selection depends on temper and corrosion considerations. Hot-cracking risk is low relative to some 2xxx and 7xxx series alloys, but HAZ softening can occur in strain-hardened tempers and may reduce local strength; proper joint design and post-weld treatments or selection of stabilized tempers mitigate this effect.

Machinability

As a relatively ductile, work-hardenable alloy, 5083 has moderate machinability compared with free-machining aluminum alloys. Typical machinability index is lower than 6xxx series; cutters with positive rake, rigid setups, and moderate speeds are recommended to avoid built-up edge and poor surface finish. Carbide tooling with controlled feeds and use of flood coolant reduces chip welding to the tool and improves life.

Formability

Forming performance is best in the O and lightly strain-hardened tempers; minimum bend radii depend on thickness and temper but are generally larger than for softer commercial-purity alloys. Cold forming is commonly used; if tighter radii or more complex shapes are required, annealing to O temper prior to forming is typical. For deep drawing and complex stampings, material in O temper followed by subsequent work-hardening or stabilization is a common production route.

Heat Treatment Behavior

EN AW-5083 is classified as a non-heat-treatable alloy; it does not gain strength through precipitation hardening. Instead, mechanical properties are modified by cold work (strain hardening) and by thermal stabilization treatments that aim to reduce susceptibility to corrosion without changing the fundamental strengthening mechanism.

Typical industrial practice uses strain-hardening (H tempers) to raise yield and tensile properties. Stabilization (e.g., H116/H321) involves low-temperature baking or controlled cooling to reduce the risk of exfoliation and to stabilize mechanical properties after welding or forming. Full annealing (O) restores ductility for forming; subsequent work-hardening or tempering operations return the part to service strength levels within the limits of non-heat-treatable behavior.

High-Temperature Performance

5083 exhibits progressive strength loss with increasing temperature and is not recommended for sustained service at elevated temperatures. Mechanical strength declines appreciably above ~100 °C, and long-term exposure above ~150 °C can lead to microstructural changes that reduce toughness and corrosion resistance. Creep resistance at elevated temperatures is limited compared to specialty high-temperature alloys.

Oxidation is minimal for short exposures, but long-term thermal exposure in aggressive atmospheres can accelerate corrosion processes. In welded assemblies, the HAZ may experience localized temper changes that reduce high-temperature capability; avoid prolonged elevated-temperature service unless validated by testing.

Applications

Industry	Example Component	Why EN AW-5083 Is Used
Marine	Hull plating, decks, superstructure	Excellent marine corrosion resistance and good strength-to-weight
Automotive	Fuel tanks, structural reinforcements	Combination of formability, weldability, and corrosion resistance
Aerospace	Fittings, non-critical structural components	Favorable damage tolerance and fatigue resistance for secondary structures
Pressure Vessels / Cryogenics	Cryogenic tanks, LPG vessels	Good toughness at low temperatures and weldability
Construction / Rail	Structural panels and floor plates	Durable, lightweight structural material with long-term corrosion performance

EN AW-5083 is chosen where a balance of corrosion resistance, weldability, and moderate-to-high strength is required. The alloy’s versatility across product forms from thin sheet to thick plate enables broad usage in structural and environmental-exposure applications.

Designers should validate specific thickness/temper combinations for fatigue-critical parts and ensure the selected temper addresses both manufacturing and in-service corrosion needs.

Selection Insights

When choosing EN AW-5083, prioritize applications where marine or chloride resistance and weldability are crucial and where heat-treatable strength is not the primary requirement. Select annealed O temper for forming, and stabilized H116/H321 tempers for long-term marine exposure or welded structures.

Compared with commercially pure aluminum (e.g., 1100), 5083 trades some electrical and thermal conductivity and formability for much higher strength and superior corrosion performance. Compared with other work-hardened alloys (e.g., 3003 / 5052), 5083 generally provides higher strength and better seawater resistance, albeit at moderate added cost. Compared with heat-treatable alloys like 6061/6063, 5083 will usually be preferred in corrosive and welded marine applications despite lower peak tensile strengths because it maintains toughness and corrosion resistance after welding.

Use this alloy when corrosion resistance, damage tolerance, and weld performance drive material selection rather than the absolute maximum yield or hardness achievable by precipitation hardening.

Closing Summary

EN AW-5083 remains a cornerstone alloy for marine and structural applications where a reliable combination of weldability, corrosion resistance, and moderate-to-high strength is required. Its non-heat-treatable strengthening mechanisms and broad range of tempers allow engineers to tailor performance across forming, welding, and in-service life-cycle demands, keeping 5083 highly relevant in contemporary engineering design.