Aluminum 5183: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

5183 is a member of the 5xxx-series aluminum alloys, which are magnesium (Mg) strengthened and classed as non-heat-treatable. The alloy is formulated to provide higher strength than the lower-Mg commercial-purity grades while retaining the corrosion resistance characteristic of the Mg-bearing family. Its principal alloying element is magnesium, typically in the mid single-digit percent range, with minor additions of chromium and trace elements to control grain structure and resist intergranular attack. The strengthening mechanism is primarily solid-solution strengthening from Mg and strain hardening for cold-worked tempers; there is no precipitation hardening route to high strength.

Key traits of 5183 include above-average tensile strength for a 5xxx alloy, excellent marine corrosion resistance, good weldability with common filler metals, and fair formability in the annealed and light strain-hardened tempers. The alloy is widely used in marine structures, vehicle components, pressure vessels, and applications where a balance of strength, toughness and seawater resistance is required. Engineers choose 5183 where 5xxx-series corrosion resistance and ductility are required with higher strength than 1100-series or 3000-series, and where the designer prefers work-hardening over heat treatment to tailor properties.

5183 is often selected over some 6xxx and 7xxx alloys when superior weldability and resistance to saltwater environments outweigh the need for the absolute highest strength. It is commonly specified in shipbuilding, offshore platforms, cryogenic tanks, and transportation components where cyclic loading and exposure to chloride environments are anticipated. The combination of mechanical performance, predictable weld behavior, and availability in sheet, plate and extruded forms makes it a pragmatic engineering choice for moderate- to high-strength aluminum structural components.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed; best forming and ductility
H111	Low-Moderate	High	Very Good	Excellent	Slightly strain-hardened; commercial general formability
H14	Moderate	Moderate	Good	Excellent	Quarter hard; common for drawing and moderate forming
H24	Moderate-High	Moderate-Low	Fair	Excellent	Stabilized strain-hardening for improved strength
H116 / H1160	Moderate-High	Moderate	Fair	Excellent	Seawater corrosion-resistant temper often used in marine applications
H32	Moderate-High	Moderate	Good	Excellent	Strain-hardened and stabilized by partial annealing
(T tempers)	Not applicable	—	—	—	5183 is non-heat-treatable; T-designations are not typical for this alloy

Temper choice strongly affects the balance of strength and ductility in 5183. Annealed (O) product provides the highest elongation and best formability for deep drawing or complex shaping, while H-series tempers progressively increase strength via cold work at the expense of elongation and stretch-forming capacity.

In practice, marine structural parts often use H116 or H32 tempers to combine enhanced yield strength with documented seawater performance and reduced susceptibility to stress-corrosion in typical service conditions. Fabricators should coordinate temper selection with forming processes and final heat exposure because temper can change during welding or hot forming.

Chemical Composition

Element	% Range	Notes
Si	0.40 max	Silicon limited to reduce hard, brittle intermetallics and maintain ductility
Fe	0.40 max	Iron controlled to limit coarse intermetallic particles that reduce formability
Mn	0.10 max	Low manganese; small amounts refine grain and improve toughness
Mg	4.5–5.5	Primary strengthening element; delivers solid-solution strength and corrosion resistance
Cu	0.10 max	Copper minimized to avoid loss of corrosion resistance and elevated galvanic activity
Zn	0.25 max	Zinc kept low to avoid susceptibility to stress corrosion cracking
Cr	0.05–0.25	Chromium used to control grain structure and reduce sensitivity to corrosion and recrystallization
Ti	0.15 max	Titanium is a grain refiner when present, often residual from processing
Others (each)	0.05 max	Minor elements and impurities limited; balance remainder Al

Magnesium is the dominant alloying element and defines the mechanical and corrosion behavior of 5183; higher Mg provides greater solid-solution strengthening and improved corrosion performance in chloride environments. Chromium acts as a microalloying addition to control grain growth during thermomechanical processing and to limit exfoliation and intergranular corrosion. Low Cu and Zn contents are intentional to preserve the alloy's marine corrosion resistance and to minimize galvanic tendencies against steels and other metals.

Mechanical Properties

In tensile behavior, 5183 exhibits a combination of moderate-to-high tensile strength and good elongation depending on temper and thickness. Annealed (O) material shows lower yield but high uniform and total elongation suitable for forming operations, while H-tempers show elevated yield and tensile strengths produced by strain hardening. Hardness correlates with temper: H-tempered or cold-worked product has higher Vickers/Brinell values than annealed product, and hardness increases with degree of cold work.

Fatigue performance in 5183 is generally favorable for the 5xxx family when surface finish, residual stresses and corrosion pits are controlled; however, fatigue life is sensitive to stress concentrators and marine corrosion pitting. Thickness influences both strength and ductility: thinner sections are easier to cold-work to higher strengths and often achieve better fatigue resistance after surface finishing, while thick plate may exhibit lower formability and different mechanical anisotropy due to rolling history.

Property	O/Annealed	Key Temper (e.g., H116/H32)	Notes
Tensile Strength	~180–260 MPa (depends on gauge)	~260–340 MPa	Wide ranges reflect thickness and degree of cold work; supplier data should be consulted
Yield Strength	~60–140 MPa	~170–300 MPa	Yield increases substantially with H-tempers and cold work
Elongation	~20–35%	~6–18%	Annealed shows high ductility; H-tempers trade ductility for strength
Hardness (HB)	~30–70 HB	~60–100 HB	Hardness scales with degree of strain-hardening and temper designation

The specific mechanical values above vary with processing route, prior thermal exposure, and product form; therefore, design should use certified mill test data for the supplied lot. When fatigue-critical components are required, specify post-fabrication treatments such as shot peening, surface finishing, or anodizing to mitigate initiation from surface defects and improve life.

Physical Properties

Property	Value	Notes
Density	~2.66 g/cm³	Typical for Al-Mg alloys; slightly lower than some Al-Zn or Al-Cu types
Melting Range	~590–640 °C	Solidus–liquidus range depends on composition and impurities
Thermal Conductivity	~120–140 W/m·K	Lower than pure aluminum but still high for heat-dissipating structures
Electrical Conductivity	~30–36 %IACS	Reduced from pure Al due to Mg alloying and other solutes
Specific Heat	~0.90 J/g·K	Near common aluminum alloy values
Thermal Expansion	~23–24 µm/m·K (20–100 °C)	Typical coefficient of thermal expansion for Al alloys

5183's thermal and electrical conductivities make it acceptable for heat spreading and some electrical applications where higher mechanical strength than pure aluminum is required. The combination of relatively high thermal conductivity and good formability enables its selection for heat-exchange panels and enclosures that encounter marine or corrosive conditions.

Designers should account for the relatively high coefficient of thermal expansion when joining 5183 to dissimilar materials to avoid thermal stress buildup during service temperature swings. The melting range guidance is important for welding and thermal cycle exposure, since melting and re-solidification during welding locally alter microstructure and mechanical properties.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.3–6 mm	Uniform across thickness; good for stamping	O, H111, H14, H116	Widely available; used for body panels and marine skins
Plate	6–200+ mm	Lower formability; supports thicker structural sections	O, H112, H116	Heavy-gauge plate for hulls, decks, and pressure vessels
Extrusion	2–200 mm cross-section	Strength depends on profile and post-extrusion strain	O, H32, H116	Longitudinal direction benefits from extrusion work; complex sections possible
Tube	OD sizes typical 6–300 mm	Strength similar to sheet in thin-wall tubes	O, H111	Used in piping, structural tubing, and heat exchangers
Bar/Rod	Diameters 5–200 mm	Solid sections achieve strength by cold work	O, H14, H24	Used in fasteners, fittings and machined components

Manufacturing routes influence mechanical anisotropy and residual stresses; sheet and plate derive their properties from rolling history, while extrusions combine alloy composition with die geometry and cooling rate. Thick plate is often supplied with controlled grain structure and temper to avoid exfoliation and to ensure adequate fracture toughness for marine and cryogenic service.

Selection between sheet, plate and extruded forms should consider downstream fabrication (forming, bending, welding) and service loads; for example, extruded complex profiles reduce the need for welding but may be more costly per-unit than flat-rolled products. Surface finish and pre-treatments such as anodizing or conversion coatings should be specified to optimize corrosion life and paint adhesion.

Equivalent Grades

Standard	Grade	Region	Notes
AA	5183	USA	Aluminum Association designation; widely used in North America
EN AW	5183	Europe	EN AW-5183 often used interchangeably, but specific EN compositions/tolerances may vary slightly
JIS	A5183	Japan	JIS variants align chemistry to local manufacturing practices
GB/T	5183	China	Chinese standard equivalents exist with similar Mg content but potential differences in impurity limits

Equivalent grade labels are nominally interoperable, but subtle differences in impurity limits, accepted microstructure, and temper designations can exist between standards. Buyers should cross-reference mill certificates and order specifications rather than relying purely on grade name, especially for mission-critical applications like marine hull fabrication or pressure vessels.

Regional practice may prefer particular tempers or supplemental specifications (e.g., H116 for marine service), so verify both chemical and mechanical acceptance criteria and request test reports to confirm compliance with the intended standard.

Corrosion Resistance

5183 offers strong resistance to general and localized corrosion in atmospheric and seawater environments, which is a key reason for its selection in marine applications. Its relatively high Mg content provides a protective, adherent oxide film and improved resistance to pitting compared with low-Mg alloys, while chromium additions help control susceptibility to intergranular and exfoliation corrosion. In chloride-rich environments, carefully controlled impurities and proper temper (such as H116) reduce the risk of active corrosion, yet surface damage and poor maintenance can still lead to pitting.

Regarding stress corrosion cracking (SCC), 5xxx-series alloys with Mg above ~3% can be susceptible under sustained tensile stress and elevated temperatures; however, 5183 has been optimized with stabilizing elements and temper control to minimize SCC in typical marine conditions. Nevertheless, design should avoid high sustained tensile stresses in warm chloride environments, and consider cathodic protection or protective coatings where appropriate. Exfoliation corrosion is generally low in 5183 relative to high-Zn or cold-worked 7xxx alloys.

Galvanic interactions must be considered when joining 5183 to dissimilar metals such as stainless steel or copper alloys. When electrically coupled in a chloride environment, aluminum becomes anodic and will corrode preferentially unless isolated by insulating materials or sacrificial protection. Compared to 6xxx-series (Al-Mg-Si) alloys, 5183 has superior seawater resistance but usually lower peak tensile strength; compared to pure aluminum (1100), 5183 trades some electrical and thermal conductivity for substantially higher mechanical strength and better marine durability.

Fabrication Properties

Weldability

5183 welds readily by common fusion processes including TIG (GTAW), MIG (GMAW) and submerged arc welding, and it responds well to gas-shielded techniques. Common filler alloys include 5356 and 5183 fillers; 5356 (Al-Mg) is frequently used to provide good strength and ductility in the weld zone and to control porosity. Hot-cracking risk in 5183 is relatively low compared with some high-strength aluminum alloys, but weld joint design, cleanliness, and control of heat input are critical to avoid porosity and to manage HAZ softening.

Machinability

Machining 5183 is moderate compared with free-machining wrought alloys; it machines better than many high-strength Al-Cu or some Al-Zn alloys but worse than 6xxx series in some cutting conditions. Use rigid setups, carbide tooling with positive rake, and pecking cycles for drilling to avoid built-up edge and poor surface finish. Recommended cutting speeds and feeds should be conservative relative to 6xxx alloys, and lubrication/coolant will assist chip evacuation and tool life.

Formability

Formability is excellent in the O temper and remains good in lightly strain-hardened tempers such as H111 and H14, allowing deep drawing, bending and spinning operations typical of marine panels and transport bodywork. Minimum bend radii depend on temper and thickness; for sheet in O temper, tight bends (r/t < 1–2) are feasible, while H-tempers require larger radii and may need intermediate annealing. For severe forming operations, specify annealed material and control springback characteristics through tool design and process parameters.

Heat Treatment Behavior

5183 is a non-heat-treatable alloy whose mechanical properties are developed by cold work (strain hardening) and can be modified by annealing or controlled thermal exposure. Solution treatment and precipitation aging processes used for heat-treatable alloys do not produce the same strengthening mechanisms in 5183, so designers should not expect T6-like property responses. Instead, annealing (O condition) softens the material to its lowest strength and maximum ductility; controlled cold working produces H-tempers with higher yield and tensile strengths.

Thermal cycles experienced during welding or hot forming can partially anneal strain-hardened tempers and cause local softening in the heat-affected zone (HAZ). Because there is no precipitation hardening to recover, strength lost by over-aging or annealing cannot be regained except by work hardening. Stabilized tempers (e.g., H116) are used to limit property changes during service and welding by combining controlled strain-hardening with thermal stabilization to reduce susceptibility to stress-corrosion and property drift.

High-Temperature Performance

At elevated temperatures, 5183 experiences a reduction in yield and tensile strength as solid-solution strengthening from Mg diminishes and recovery processes accelerate. Practical continuous service temperatures are typically limited to around 100–150 °C for load-bearing applications; prolonged exposure above these temperatures can materially reduce mechanical capacity and increase creep rates. Oxidation of aluminum is minimal compared with ferrous alloys, but surface scaling and loss of mechanical integrity due to grain boundary weakening can occur with sustained high-temperature exposure.

The HAZ produced by welding is particularly sensitive because local temperatures approach melting and induce microstructural changes; designers should avoid operating conditions that combine elevated temperature with high sustained tensile stresses in chloride environments to limit SCC risk. For transient elevated-temperature exposures, consider thicker sections, stress-relief designs, and protective coatings to preserve long-term performance.

Applications

Industry	Example Component	Why 5183 Is Used
Marine	Hull plating, decks, bulkheads	Excellent seawater corrosion resistance and good strength-to-weight
Automotive & Transport	Trailer floors, structural panels	Good formability and resistance to roadside de-icing salts
Aerospace & Defense	Secondary structures, panels, fittings	Favorable strength, toughness and weldability for large fabricated assemblies
Pressure Vessels / Cryogenics	Liquefied gas tanks, cryogenic vessels	Good low-temperature toughness and weldability
Electronics / Heat Management	Enclosures, chassis	High thermal conductivity combined with corrosion resistance

5183's combination of moderate-to-high strength, weldability, and marine-grade corrosion resistance keeps it in broad use for structures and components that operate in harsh environments. Its particular suitability for welded, fabricative construction and for parts requiring both duct