Aluminum 6082: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

6082 is a member of the 6xxx series of aluminum alloys, which are primarily aluminum-magnesium-silicon (Al-Mg-Si) compositions. This series is characterized by its ability to be strengthened by heat treatment through precipitation hardening, offering a balance of strength, corrosion resistance, and good extrudability compared with other alloy families.

Major alloying elements in 6082 are magnesium and silicon, which combine to form the Mg2Si precipitates responsible for age-hardening. Secondary additions such as manganese and chromium refine grain structure, improve toughness and control recrystallization during thermomechanical processing, imparting enhanced tensile properties relative to many 5xxx and 3xxx alloys.

The strengthening mechanism is heat-treatable precipitation hardening (solution treating, quenching and aging). Key traits include relatively high static strength among 6xxx alloys, good corrosion resistance in atmospheric and mildly marine environments, favorable weldability with some HAZ softening, and fair formability in softer tempers. These traits make 6082 suitable for structural sections, extrusions, and components where strength-to-weight and manufacturability are both important.

Typical industries using 6082 include transport and commercial vehicle construction, marine and offshore structures, general engineering, and structural extrusions for building and architectural systems. Engineers choose 6082 over other alloys when a combination of higher strength (vs. 6063 and many 5xxx work-hardened alloys), good extrudability, and reliable corrosion performance is required for medium-duty structural applications.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (20–30%)	Excellent	Excellent	Fully annealed, maximum ductility and formability for complex shaping
H12	Low–Medium	Moderate (12–18%)	Good	Excellent	Work-hardened, limited amount of strain hardening for moderate strength
H14	Medium	Moderate (10–15%)	Good	Excellent	Common cold-worked temper providing higher yield without aging
T5	Medium–High	Moderate (8–12%)	Fair	Good	Cooled from elevated temperature shaping and artificially aged; often for extrusions
T6	High	Lower (8–12%)	Limited	Good	Solution heat-treated and artificially aged to reach near-peak strength
T651	High	Lower (8–12%)	Limited	Good	T6 plus stress relief by stretching to minimize residual stresses, common for structural uses

Temper selection controls the trade-offs between strength, ductility, formability and residual stress. Annealed (O) condition maximizes formability and elongation for stamping and deep drawing, while T6/T651 give the highest static strength at the expense of reduced ductility and some cold-forming capability.

Tempering also affects weld behavior and post-weld properties because the heat-affected zone (HAZ) can experience softening in precipitation-hardened tempers; T651 is often used when dimensional stability and residual stress control are important after heat treatments or machining.

Chemical Composition

Element	% Range	Notes
Si	0.6–1.3	Silicon combines with magnesium to form Mg2Si precipitates; controls strength and melting range.
Fe	0.0–0.5	Iron is an impurity that forms intermetallics, reducing ductility and slight effects on corrosion and machining.
Mn	0.4–1.0	Manganese refines grain structure and improves strength and toughness, especially in heavy sections.
Mg	0.6–1.2	Magnesium is a primary strengthening element forming Mg2Si; influences age-hardening response.
Cu	0.0–0.1 (up to 0.2)	Small copper improves strength but can reduce corrosion resistance if present in higher amounts.
Zn	0.0–0.25	Zinc is typically kept low; higher zinc levels are not desired in 6xxx alloys.
Cr	0.0–0.25	Chromium helps control grain structure, reduces recrystallization and improves toughness.
Ti	0.0–0.1	Titanium used as grain refiner in ingot metallurgy and primary metallurgy.
Others (each)	Balance trace	Other trace elements and residuals are controlled to maintain mechanical and corrosion properties.

The Al-Mg-Si system is carefully balanced so Mg and Si combine to form the strengthening Mg2Si precipitates during aging. Manganese and chromium help stabilize microstructure during thermomechanical processing, reduce undesirable grain growth and improve toughness, while iron and other impurities form brittle intermetallics that can reduce ductility and fatigue performance if excessive.

Mechanical Properties

6082 shows a strong dependence of tensile behavior on temper and thickness due to precipitation hardening and work hardening. In T6/T651 states the alloy develops high proof and ultimate strengths due to coherent/semi-coherent Mg2Si precipitates; these precipitates also reduce ductility compared to annealed states. Thickness effects are notable: thicker sections can be more difficult to solution-treat uniformly and may contain coarser precipitates or partial overaging leading to reduced strength.

Yield strength in peak-aged tempers is substantially higher than in annealed conditions; however, welds and the HAZ commonly show softening due to dissolution or coarsening of strengthening phases. Fatigue behavior is generally good for aluminum alloys with smooth surfaces and controlled residual stresses, but fatigue life is sensitive to surface quality, applied mean stress, and local stress concentrators from machining or forming.

Hardness correlates with tensile properties and also varies with temper and aging schedule; overaging reduces hardness but can improve toughness and stress-corrosion resistance. For design, engineers should account for temper-specific yield and endurance limits, and may specify T651 for applications requiring minimal residual distortion and stable fatigue performance.

Property	O/Annealed	Key Temper (T6/T651)	Notes
Tensile Strength (UTS)	~100–150 MPa	~300–360 MPa	T6/T651 typical peak-aged range; values depend on section thickness and heat treatment quality.
Yield Strength (0.2% proof)	~40–80 MPa	~240–300 MPa	Yield increase from aging is significant; designers should use temper-specific certified values.
Elongation	~20–30%	~8–12%	Ductility decreases as strength increases; thinner sections often show higher elongation.
Hardness (HB)	~25–40 HB	~80–110 HB	Brinell hardness correlates with tensile strength; hardness varies with aging and section geometry.

Physical Properties

Property	Value	Notes
Density	2.70 g/cm³	Typical for wrought aluminum alloys, used for weight-sensitive design calculations.
Melting Range	~555–650 °C	Solidus/liquidus spread depends on alloying; careful control needed during welding and brazing.
Thermal Conductivity	~160–200 W/m·K	Lower than pure Al but still high compared with steels; good for heat-dissipation roles.
Electrical Conductivity	~30–40 %IACS	Reduced versus pure aluminum due to alloying additions; important for electrical applications.
Specific Heat	~0.9 J/g·K (900 J/kg·K)	Useful for thermal mass and transient thermal calculations in components.
Thermal Expansion	~23–24 µm/m·K (20–100 °C)	Typical coefficient of linear expansion for aluminum alloys; affects bolted/jointed assemblies with dissimilar materials.

6082 retains the favorable density-to-strength ratio that makes aluminum attractive for lightweight structural applications. Its thermal conductivity and specific heat are high enough for many heat-sink or thermal management tasks, but design must account for lower conductivity compared with pure aluminum and differing expansion rates when joining to steels or composites.

Melting range and thermal properties inform welding and heat-treatment schedules; due to relatively broad solidus-liquidus intervals, localized heating paths during welding can produce porosity or liquation unless parameters are controlled. Electrical conductivity is adequate for some busbar or conductor applications but is often traded off against strength in structural uses.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.3–6 mm	Strength varies with temper; thinner gauges age more uniformly	O, H14, T4, T6	Widely used where stamping and forming are required; thickness limits heat-treatment effectiveness.
Plate	6–120 mm	Potential for reduced peak strength in very thick plates due to quench/age gradients	O, T6/T651	Heavy sections need controlled solution treatment and quench to avoid soft cores.
Extrusion	Profiles up to several meters in length	Excellent mechanical properties when properly heat-treated; geometry affects aging	T5, T6, T651	6082 is a preferred structural extrusion alloy due to strength and good surface finish after anodizing.
Tube	Ø small to large, wall thickness variable	Similar temper dependency as sheet; cold drawing affects properties	O, T6	Common in structural and architectural tubing; welded and seamless processes used.
Bar/Rod	Ø 6–200 mm	Mechanical properties depend on cross-section and temper	O, T6	Used for machined fittings and forgings; stress-relieved tempers are common for machining stability.

Different product forms demand different processing controls. Extrusions are the dominant commercial form for 6082, with profiles heat-treated after quench to obtain T6/T651 properties; plate and heavy sections require more careful heat treatment and quenching to achieve uniform properties through thickness. Sheet and thin forms are easier to solution treat and age uniformly, making them more predictable for tensile and fatigue performance.

Selection of form also impacts surface finish, residual stresses, and post-processing needs such as straightening, stretching, or additional machining. Engineers should specify temper and processing route early to ensure required mechanical and dimensional specifications are achievable in the chosen form.

Equivalent Grades

Standard	Grade	Region	Notes
AA	6082	USA	Recognized by the Aluminum Association designation; availability in North America is more limited than in Europe.
EN AW	6082	Europe	Widely used and specified in European standards with well-defined tempers (T6, T651).
JIS	—	Japan	No direct one-to-one JIS equivalent; 6063 or 6061 are the closest commonly available alternatives in performance.
GB/T	6082	China	Commercially available and specified in Chinese standards; chemistry and tempers align closely with EN AW-6082.

While the AA/EN AW 6082 designation is straightforward in Europe and many international catalogs, there is no exact one-to-one equivalent in all national standards; 6061 and 6063 are the most similar North American/Japanese alternatives in terms of general application space. Differences can be subtle but important: variations in allowable Mn, Cr, and Mg ranges, product form availability, and typical processing routes can lead to different mechanical property envelopes and corrosion performance in practice.

Corrosion Resistance

6082 exhibits good general atmospheric corrosion resistance for structural applications and is often used in building, transport, and marine-adjacent roles. Its Mg and Si content provides adequate resistance to mild industrial and rural environments, and surface treatments such as anodizing or painting can greatly enhance appearance and long-term corrosion protection.

In marine environments 6082 performs reasonably well in splash and atmospheric salt exposure, but active immersion in chloride-rich seawater accelerates pitting and localized corrosion compared with more highly alloyed marine-specific 5xxx series alloys. Preventive measures include protective coatings, anodizing, and careful design to avoid crevices and stagnant salt deposition.

Stress corrosion cracking susceptibility in 6082 is lower than in high-strength 2xxx and 7xxx series alloys, but peak-aged conditions can still show embrittlement under certain combinations of tensile stress and corrosive media. Galvanic coupling with more noble metals such as stainless steel or copper can accelerate localized corrosion of aluminum; designers should insulate dissimilar metals or use sacrificial treatments and coatings.

Compared to work-hardened 5xxx alloys, 6082 trades a small corrosion performance penalty for higher static strength; compared to 6xxx family members such as 6063, 6082 usually offers similar or slightly better corrosion resistance due to chemistry differences and heat-treatment response but must be evaluated on a case-by-case basis for specific environments.

Fabrication Properties

Weldability

Welding of 6082 by MIG (GMAW) and TIG (GTAW) is common and generally straightforward with appropriate filler selection. Filler alloys such as 4043 (Al-Si) or 5356 (Al-Mg) are commonly used depending on desired mechanical properties and corrosion resistance; 4043 minimizes hot-cracking risk whereas 5356 gives higher strength but slightly higher susceptibility to galvanic corrosion. Post-weld heat treatments are often required to restore strength in HAZ-softened regions, and joint design should account for HAZ softening in T6 condition.

Machinability

Machinability of 6082 is fair to good; it machines better than many 5xxx alloys and comparably to 6061 in many operations. Carbide tooling and positive rake geometries are recommended for turning and milling, with moderate cutting speeds and high feed rates to avoid built-up edge; coolant and chip evacuation are important to maintain surface finish. Threading and high-precision features should account for temper and possible residual stresses; stress-relief (T651) improves dimensional stability for machining-intensive components.

Formability

Formability varies strongly with temper: O and H-state tempers offer excellent formability suitable for bending, deep drawing and roll forming, while T6/T651 have limited cold-forming capability and require larger bend radii. Recommended minimum bend radii depend on thickness and temper but are typically in the 1–3× thickness range for O/H tempers and larger for T6; warm forming or aging after forming (forming in T4 then aging to T6) is often used to reconcile formability and strength requirements. Springback is significant in aluminum; tooling and process control must compensate for elastic recovery.

Heat Treatment Behavior

6082 is heat-treatable: the standard sequence for peak strength is solution heat treatment, rapid quenching, and artificial aging. Typical solution treatment temperatures are in the 510–540 °C range, followed by rapid quenching in water to retain Mg and Si in supersaturated solid solution. Artificial aging (T6) is commonly performed at temperatures around 160–185 °C for times varying from several hours to more than ten hours depending on desired temper and part thickness.

T5 tempers involve cooling from hot working and direct artificial aging without a prior solution treatment, offering a balance of manufacturability and strength for extrusions. The T651 temper is T6 plus a controlled stretching operation to minimize residual stresses and distortions, which is common for structural components requiring tight dimensional tolerances.

Overaging softens the alloy by coarsening precipitates and can improve toughness and stress-corrosion resistance at the expense of peak strength. Thick sections may require modified solution treatment and aging schedules to achieve uniform properties; quench rate sensitivity should be considered during process design.

High-Temperature Performance

6082 experiences progressive strength loss with increasing temperature as the Mg2Si precipitates dissolve or coarsen, reducing the effectiveness of precipitation strengthening. Useful static mechanical performance generally extends to approximately 100–120 °C; above this range designers should expect significant reductions in yield and tensile strengths and consider alternative alloys or design margins.

Oxidation at elevated temperatures is not a primary degradation mechanism for short exposures, but prolonged high-temperature exposure can alter surface condition and microstructure. The HAZ formed during welding exhibits altered precipitate distributions and potential softening; these effects can be exacerbated by subsequent thermal cycling and localized heating.

Creep resistance at elevated temperatures is limited compared with high-temperature alloys, so 6082 is not appropriate for sustained loading at high temperatures. For intermittent thermal exposure, component life must be evaluated considering both thermal softening and possible fatigue/coarsening effects.

Applications

Industry	Example Component	Why 6082 Is Used
Automotive & Transport	Structural extrusions, chassis components	High strength-to-weight and good extrudability for profiles and sections
Marine & Offshore	Deck structures, rails, fittings	Good atmospheric and splash-zone corrosion resistance plus formability
Aerospace (non-primary)	Fittings, brackets, fairings	Favorable strength, machinability and anodizing response for secondary structures
Electronics & Thermal Management	Heat sinks, housings	Good thermal conductivity and light weight for thermal solutions
Building & Architecture	Window frames, curtain wall extrusions	Surface finish, corrosion resistance and structural capability for facade systems

6082 is often selected where a structural profile or component must provide higher static strength than 6063 while retaining good extrudability and finishability. Its balance of mechanical properties, corrosion resistance and cost effectiveness keeps it in wide use for medium-duty structural roles across multiple industries.

Selection Insights

For engineers and purchasers, 6082 is a solid choice when you need higher structural strength than standard architectural 6xxx alloys but still require good extrusion quality and anodizing aesthetics. Specify T6/T651 when maximum static strength and dimensional stability are required, and use O or H tempers for heavy forming operations followed by an artificial aging route if a higher final strength is needed.

Compared with commercially pure aluminum (1100), 6082 sacrifices some electrical and thermal conductivity and formability in exchange for dramatically higher yield and ultimate strength. Compared with work-hardened alloys such as 3003 or 5052, 6082 provides significantly higher peak strength at comparable or slightly lower corrosion resistance, making it preferable for load-bearing structures where strength is the priority. Compared with other heat-treatable alloys like 6061 and 6063, 6082 is often preferred for extruded structural sections where slightly higher machinability and strength are wanted despite 6061 sometimes having better balanced machinability and 6063 better surface finish for architectural applications.

Closing Summary

6082 remains relevant because it delivers a well-rounded combination of higher strength, good corrosion resistance, and excellent extrudability that many structural applications demand. Its heat-treatable nature allows designers to tune the strength-ductility balance, while common availability in extruded profiles and plates makes it a practical choice for engineering projects where weight, cost and manufacturability are jointly considered.