Aluminum EN AW-6060: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

EN AW-6060 is a 6xxx-series aluminium alloy (Al-Mg-Si family) commonly referenced as 6060 in American standards and EN AW-6060 in European practice. It belongs to the heat-treatable aluminium-silicon-magnesium alloys that combine moderate strength with excellent extrudability and surface finish. The principal alloying elements are silicon and magnesium, which form Mg2Si precipitates during heat treatment to provide strengthening by precipitation hardening. Typical traits include medium strength, very good corrosion resistance in atmospheric conditions, good weldability, and excellent formability in annealed and naturally aged tempers.

Industries that most frequently use EN AW-6060 include architectural extrusion, building and construction, automotive secondary structural members, and general engineering components such as profiles, tubing, and rails. The alloy is chosen where a balance of extrudability, machinability, surface finish (anodizing behavior), and adequate strength-to-weight ratio are required. Designers often prefer 6060 over softer commercial-purity alloys when mechanical stability is needed, and they prefer it over higher-strength 6xxx variants when extrusion surface quality, dimensional tolerance, or improved formability is prioritized.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed, maximum ductility and formability
H14	Moderate-Low	Moderate	Good	Excellent	Strain-hardened, limited cold forming, used for lightweight sections
T5	Moderate	Moderate	Good	Good	Cooled from hot working and artificially aged, common for extrusions
T6	High	Low-Moderate	Fair	Moderate	Solution treated and artificially aged for peak strength
T651	High	Low-Moderate	Fair	Moderate	Solution treated, stress-relieved by stretching, used for stable dimensions

The temper chosen for EN AW-6060 strongly affects mechanical behavior and formability. Annealed (O) tempers deliver best ductility for bending and deep drawing, while T6 gives the highest yield and tensile strengths at the expense of elongation and cold formability.

Heat-treatable tempers such as T5 and T6 also influence dimensional stability and post-fabrication distortion; T651 is often specified where residual stresses must be minimized after solution heat treatment and quenching.

Chemical Composition

Element	% Range	Notes
Si	0.30–0.60	Silicon contributes to Mg2Si formation and improves extrudability and surface finish.
Fe	≤0.15	Iron is an impurity that can form intermetallics; kept low to preserve ductility and surface appearance.
Mn	≤0.05	Manganese is minimal in this alloy; negligible hardening effect.
Mg	0.35–0.50	Magnesium combines with silicon to form Mg2Si precipitates for age hardening.
Cu	≤0.05	Copper is low to limit strength loss in corrosive environments.
Zn	≤0.10	Zinc is controlled tightly; not a principal strengthening element here.
Cr	≤0.05	Chromium is limited; helps control grain structure in some variants.
Ti	≤0.10	Titanium may be present in trace amounts for grain refinement in castings or ingots.
Others (each)	≤0.05	Residuals and trace elements are limited to preserve alloy properties.

The Mg and Si ratio is crucial because the Mg2Si precipitate is the primary strengthening phase after solution treatment and aging. Low iron and other impurities are maintained to protect surface finish, extrudability, and ductility; silicon content also improves flow during extrusion and enhances anodizing appearance.

Mechanical Properties

Tensile behavior in EN AW-6060 reflects a classical precipitation-hardened response: annealed material shows low yield with high uniform elongation, while peak-aged tempers show significantly increased tensile and yield strength with reduced ductility. Yield points are sensitive to section thickness and temper history; thinner extrusions and well-controlled heat treatments produce higher effective yield and tensile strengths. Hardness tracks with precipitation state and is therefore a useful in-process control metric during aging operations.

Fatigue behavior is reasonable for moderate-stress applications; fatigue strength is heavily influenced by surface finish, anodizing defects, and extruded profile geometry. Notched or cold-worked features reduce fatigue life disproportionately compared to smooth specimens because of stress concentration effects. Thickness and cross-sectional geometry alter quench rates during heat treatment and therefore affect precipitate distribution; heavier sections typically have slightly reduced peak achievable strength and may require modified heat treatment cycles.

Microstructural condition, including distribution of Mg2Si precipitates and presence of coarse intermetallics, controls fracture behavior and ductility transitions between tempers. Welded joints will show softened heat-affected zones relative to parent T6 material, reducing local static and fatigue strengths unless post-weld heat treatment or selection of compatible filler metal is performed.

Property	O/Annealed	Key Temper (T6)	Notes
Tensile Strength	95–140 MPa	170–230 MPa	Values depend on section thickness and exact aging practice.
Yield Strength	35–80 MPa	110–170 MPa	Yield can be very low in O temper and increases substantially with T6.
Elongation	12–25%	6–12%	Elongation falls with higher strength tempers and thicker sections.
Hardness	~35–45 HV	~60–90 HV	Hardness correlates with precipitate volume fraction; used as QA check.

Physical Properties

Property	Value	Notes
Density	2.70 g/cm³	Typical for wrought aluminium alloys; useful for weight-sensitive design calculations.
Melting Range	~555–650 °C	Solidus-liquidus interval depends on alloying and minor constituents.
Thermal Conductivity	~160–180 W/m·K	Lower than pure aluminium but high compared with steels; good for heat dissipation.
Electrical Conductivity	~30–40 % IACS	Reduced compared with pure aluminium due to alloying; adequate for non-critical conductor use.
Specific Heat	~900 J/kg·K	Typical specific heat for aluminium alloys at ambient temperatures.
Thermal Expansion	~23–24 ×10⁻⁶ /K	Relatively high expansion; important for assemblies combining dissimilar materials.

EN AW-6060 combines good thermal conduction with light weight, which makes it suitable for heat-dissipating components where structural weight matters. The moderate electrical conductivity precludes its use where maximum conductivity is required, but it remains acceptable for many electronic housings and conductive structural items.

The melting range and thermal expansion characteristics dictate caution during welding and thermal processing to avoid distortion and to select compatible joining methods and fixturing strategies for assemblies comprising mixed materials.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.5–6 mm	Uniform strength, sensitive to cold work	O, H14, T5	Used in panels, cladding, and fabricated parts.
Plate	>6–50 mm	Lower peak strength due to slower quench	O, T6 (limited)	Large plates less common but used for structural sections.
Extrusion	Thin-walled to complex profiles	Excellent, optimized by temper	T5, T6, T651	Primary commercial form for EN AW-6060 due to excellent flow and surface finish.
Tube	1–10 mm wall, various diameters	Similar to extrusions, may be cold-drawn	O, T6	Used for railing, frames and pressurized low-pressure applications.
Bar/Rod	6–60 mm	Good dimensional stability	O, T6	Machining stock and turned components manufactured from bar stock.

Extrusion is the dominant processing route for EN AW-6060 because the alloy flows well and produces good surface quality and tight dimensional tolerances. Sheet and plate operations require different rolling schedules and heat treatments to balance strength and formability, and thick sections are less able to achieve peak T6 properties without special quench practices.

Cold work and secondary fabrication steps such as bending, punching, or drawing are most efficient in O or T4/T5 conditions; T6 components are often machined or left in service where stiffness and strength must be maximized rather than deep forming.

Equivalent Grades

Standard	Grade	Region	Notes
AA	6060	USA	Common US designation aligning with ASTM definitions for wrought 6xxx alloys.
EN AW	6060	Europe	EN AW-6060 is the European designation per EN standards; mechanical properties often specified by temper.
JIS	A6060	Japan	JIS uses similar chemistry but can have slightly different limits on impurities.
GB/T	6060	China	Chinese standard equivalent; slight tolerances may differ for extruded products.

Equivalent grades across standards are broadly similar in chemistry but tolerances and guaranteed mechanical properties may differ based on country-specific specifications and product form (extruded profile vs. sheet). Buyers should confirm temper definitions and lot testing requirements because terms like T6 or T651 map differently to certification requirements and dimensional tolerances in some standards.

Corrosion Resistance

EN AW-6060 exhibits good general atmospheric corrosion resistance due to the protective aluminium oxide layer and the relatively low copper content in its chemistry. In urban and rural environments it performs well, and anodizing enhances both appearance and corrosion resistance for architectural and exposed applications. The presence of Mg and Si does not significantly compromise barrier corrosion performance; localized attack is most likely at surface defects or mechanical damage.

In marine environments the alloy is moderately resistant but can suffer from pitting and crevice corrosion if chloride exposure is prolonged and protective coatings are compromised. Design for marine use typically incorporates protective coatings, anodizing and drainage to minimize stagnant seawater contact. Galvanic interaction with more noble metals such as stainless steels or copper-bearing alloys can accelerate aluminium corrosion when electrical contact and electrolyte are present; appropriate isolation or sacrificial anode strategies are required.

Stress corrosion cracking (SCC) susceptibility is low for 6xxx-series alloys compared with some high-strength 2xxx and 7xxx families, particularly in the tempers commonly used for extrusions. However, localized SCC or exfoliation can occur under severe environments and sustained tensile stresses; post-weld treatments and proper design to reduce tensile residual stresses mitigate these risks.

Fabrication Properties

Weldability

EN AW-6060 welds well by TIG and MIG processes when correct filler alloys and procedures are used; heat input and joint preparation control porosity and HAZ softening. Common filler materials include AlSi (e.g., 4043) and AlMgSi fillers designed to match mechanical properties and reduce hot cracking risk; filler choice depends on required post-weld strength and service environment. Hot-cracking risk is moderate but manageable with appropriate weld sequence, preheat where needed, and control of restraint; note that welded regions of T6 material will typically be softer in the HAZ due to precipitate dissolution.

Machinability

Machinability of EN AW-6060 is generally good, better than many purer aluminium grades due to silicon content that improves chip control. Carbide tooling with fine positive geometry and good coolant/lubrication provides best surface finish and tool life; recommended cutting speeds are moderate to high with high feed for roughing and reduced depth for finishing. Chips tend to be continuous and can adhere; chip breakers and coolant strategies are valuable to prevent tool clogging and improve dimensional control.

Formability

Formability is excellent in O or T4 conditions, allowing bending, deep drawing, and roll-forming with relatively small bend radii and minimal springback. In T6 conditions formability decreases substantially and stamping or severe bending is not recommended without local annealing or solutionizing. Recommended minimum internal bend radii for sheet in O temper are typically around 1–1.5× thickness for simple bends; more complex draws or stretch forming require matched tooling and possible pre-heating or lubrication.

Heat Treatment Behavior

EN AW-6060 is a heat-treatable alloy whose primary strengthening route is precipitation hardening via Mg2Si formation. Solution treatment is performed at temperatures generally in the range of 520–550 °C to dissolve existing precipitates, followed by rapid quenching to retain a supersaturated solid solution. Artificial aging (precipitation heat treatment) is typically performed between 160–200 °C for times depending on desired strength; T5 refers to artificial aging without prior solution treatment (commonly applied to extrusions cooled from hot working), while T6 designates solution treatment plus artificial aging.

Temper transitions from natural aging (T4) to artificial aging (T6) are used to tailor the balance of strength and ductility; natural aging yields moderate strength while artificial aging produces higher peak strength. Overaging at elevated temperatures coarsens precipitates and reduces strength but improves fracture toughness and dimensional stability; therefore designers sometimes choose intermediate tempers to minimize distortion.

For applications where heat treatment is impractical, cold work can provide limited strengthening but is not the primary mechanism for 6060; annealing to O returns material to maximum ductility for forming and subsequent machining.

High-Temperature Performance

EN AW-6060 experiences progressive strength loss as temperature increases; notable loss of yield and tensile strength begins above approximately 120–150 °C for sustained service. Short-term exposure up to about 200 °C may be tolerable but will accelerate precipitate coarsening and reduce peak-age temper performance. Oxidation is minimal at these temperatures due to the protective oxide film, but prolonged exposure at elevated temperatures will alter mechanical properties and may require re-qualification.

Welded and heat-treated zones are particularly sensitive to elevated service temperatures because precipitate stability in the HAZ and base metal controls mechanical behavior. For cyclic thermal environments, differential expansion and changes in modulus must be accounted for in bolted joints and multi-material assemblies to avoid fatigue or loosening.

Applications

Industry	Example Component	Why EN AW-6060 Is Used
Automotive	Trim, rails, non-critical structural profiles	Good extrudability, surface finish, and adequate strength for secondary structures
Marine	Window frames, rails, architectural fittings	Corrosion resistance and anodizing compatibility for exposed environments
Aerospace	Interior fittings, non-primary structural extrusions	Lightweight and good dimensional control for secondary components
Electronics	Heat sinks, enclosures	Thermal conductivity combined with formability and finish quality

EN AW-6060 is primarily selected for extruded profiles where surface appearance, consistent cross-section quality and reasonable mechanical strength are required. Its balance of properties makes it a cost-effective option for many architectural and transport applications where ultrahigh strength is not necessary.

Selection Insights

EN AW-6060 is a practical choice when you need better strength than commercially pure aluminium (1100) while retaining good formability and surface finish. Compared with 1100, 6060 trades a modest reduction in electrical conductivity for a substantial increase in tensile and yield strength and better extrusion characteristics.

Against work-hardened alloys like 3003 or 5052, EN AW-6060 sits higher in peak strength after aging and offers superior anodizing appearance; however, 3xxx and 5xxx alloys may provide better ductility in heavy forming and often superior resistance to certain marine corrosion modes. When compared with higher-strength heat-treatable alloys such as 6061 or higher-strength 6xxx variants, 6060 is often preferred for complex extrusions and superior surface finish even though it has lower peak strength; choose 6060 when extrudability, finish and cost are prioritized over absolute strength.

When selecting material, weigh the need for deep drawing versus final strength: specify O or T4/T5 for forming operations and T6/T651 for finished parts requiring higher stiffness and strength, keeping in mind weld-affected zones and possible need for post-weld treatments.

Closing Summary

EN AW-6060 remains a widely used aluminium alloy because it offers a balanced combination of extrusion performance, surface finish, corrosion resistance and adequate aging-strength for many structural and architectural applications. Its versatility across tempers and product forms makes it a cost-effective choice for engineers seeking reliable performance without the complexities or costs of higher-strength aluminium systems.