Aluminum EN AW-1050A: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

EN AW-1050A is a member of the 1xxx series of aluminium alloys, representing commercially pure aluminium with a minimum nominal aluminium content of approximately 99.5%. The alloy is intentionally kept low in alloying additions, with silicon, iron and trace elements present only at impurity levels, which preserves the base metal properties associated with the 1xxx family. The alloy is not heat-treatable; its mechanical strength is derived almost exclusively from strain (work) hardening and the base metal purity, which gives a very homogeneous microstructure and predictable deformation response.

Key technical traits of EN AW-1050A include low mechanical strength relative to alloyed series, very high electrical and thermal conductivity, excellent corrosion resistance in many atmospheres, outstanding formability for complex cold deformation, and excellent weldability by common fusion processes. Typical industries using EN AW-1050A are electrical conductors and busbars, chemical and food processing equipment, reflectors and decorative architectural elements, and thin-gauge packaging and foil applications. Engineers select 1050A when maximum conductivity, surface finish, corrosion resistance and formability are required and when high strength is not the primary design driver.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed condition for maximum ductility
H12	Low-Medium	Medium	Very Good	Excellent	Light strain hardening, retains good forming capability
H14	Medium	Medium-Low	Good	Excellent	Common cold-worked temper for sheet applications
H16	Medium-High	Lower	Fair	Excellent	Increased work hardening for higher strength
H18	High	Low	Limited	Excellent	Heavily strain-hardened for maximum strength in non-formed parts
H112	Variable	Variable	Variable	Excellent	Non-heat-treated; mechanical properties not controlled by full strain hardening; common for extrusions

Cold working (H-temper) is the only practical route to increase strength in EN AW-1050A because it does not respond to age-hardening heat treatment. The O temper yields the highest ductility and formability, while incremental H-temper designations reflect greater degrees of strain hardening and correspondingly higher yield and tensile strengths with reduced elongation.

Chemical Composition

Element	% Range	Notes
Si	≤ 0.25	Typical impurity from processing; low enough to retain high conductivity
Fe	≤ 0.40	Main impurity; affects strength and surface finish at higher levels
Mn	≤ 0.05	Minimal; negligible strengthening contribution
Mg	≤ 0.05	Minimal; not used for age hardening in this alloy
Cu	≤ 0.05	Kept very low to preserve corrosion resistance and conductivity
Zn	≤ 0.05	Low; avoids significant galvanic effects and maintains conductivity
Cr	≤ 0.05	Trace levels; may refine grain if present
Ti	≤ 0.03	Often used for grain control in cast/extruded products
Others	≤ 0.15 total	Includes trace impurities; Al remainder ≥ 99.5%

The near-pure aluminium chemistry of EN AW-1050A maximizes electrical and thermal conductivity while minimizing intermetallic phases that would otherwise reduce ductility and surface quality. Small concentrations of iron and silicon are unavoidable and contribute modestly to strength and to the formation of fine intermetallic particles that can influence forming, surface finish and etching behavior.

Mechanical Properties

EN AW-1050A exhibits tensile behavior typical of low-alloyed, high-purity aluminium: low modulus of elasticity relative to steel but high ductility in the annealed condition. Yield strength is low and generally increases with cold work while total elongation decreases; engineers must account for thickness-dependent strengthening and the influence of fabrication history. Hardness values are correspondingly low, and fatigue strength is modest; fatigue performance is strongly influenced by surface condition, residual stresses from forming and the presence of any notches or welds.

In strain-hardened tempers a useful compromise is reached between higher tensile and yield properties and acceptable formability for many sheet metal applications. Because the alloy lacks precipitation strengthening mechanisms, all significant increases in static strength come from dislocation accumulation and microstructural work hardening. Thickness and surface finish materially affect both fatigue life and the scatter in tensile properties, so specification of temper and product form is critical for repeatable mechanical performance.

Property	O/Annealed	Key Temper (H14/H16)	Notes
Tensile Strength	Typical 60–110 MPa	Typical 95–140 MPa	Values vary with thickness and degree of cold work
Yield Strength	Typical 25–55 MPa	Typical 60–120 MPa	Yield increases significantly with H-temper designation
Elongation	Typical 30–45%	Typical 6–20%	Annealed condition yields highest elongation; H18 lowest
Hardness	Typical 15–30 HB	Typical 20–40 HB	Hardness rises with work hardening; surface-dependent

Physical Properties

Property	Value	Notes
Density	2.71 g/cm³	Typical for near-pure aluminium
Melting Range	~ 660 °C (approx.)	Alloy is nearly pure aluminium; narrow melting range near pure Al
Thermal Conductivity	~ 230 W/m·K	High among engineering metals; dependent on purity and temperature
Electrical Conductivity	~ 58–62 %IACS	Very good electrical conductor; varies with temper and impurities
Specific Heat	~ 900 J/kg·K	High specific heat useful in thermal buffer applications
Thermal Expansion	~ 23.5 ×10⁻⁶ /K	Relatively high thermal expansion compared with steels

The physical property set explains much of EN AW-1050A's application space: the combination of high thermal and electrical conductivity with low density makes it an ideal choice for heat sinks, conductors and reflective surfaces. The relatively high coefficient of thermal expansion requires attention in assemblies with dissimilar materials to control thermal stresses and dimensional stability.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2–6.0 mm	Strength increases with H-tempers	O, H12, H14, H16	Widely used for deep drawing, reflectors, decorative panels
Plate	> 6.0 mm	Similar trend; lower formability at larger thickness	O, H112	Less common; used where thicker gauge corrosion-resistant parts needed
Extrusion	Profiles up to large cross-sections	Mechanical properties depend on post-extrusion cold work	H112, H14 for drawn profiles	Often used for architectural framing and bus bars
Tube	Thin- to thick-wall tubes; OD variable	Cold drawing and annealing alter properties	O, H16	Common for chemical and heat exchanger applications
Bar/Rod	Diameters from mm to 50+ mm	Limited work hardening achievable by drawing	O, H18, H112	Used for fasteners, studs, and machined components where conductivity matters

Sheet products are the most common form of 1050A and are typically specified with controlled surface finishes for decorative and reflective roles. Extrusions and tubes often use H112 or light H-tempers to provide dimensional stability and adequate strength while retaining good weldability and corrosion performance.

Equivalent Grades

Standard	Grade	Region	Notes
AA	1050A	USA	US Aluminum Association designation commonly used interchangeably with EN AW-1050A
EN AW	1050A	Europe	EN standard designation; widely used in EU specifications
JIS	A1050	Japan	Equivalent commercially pure aluminium with similar impurity limits
GB/T	1050	China	Chinese standard close in chemistry; manufacturing and test practice may differ

Equivalent grade listings are approximate: while chemistry and principal properties align broadly across international standards, subtle differences exist in impurity limits, guaranteed conductivity, surface quality requirements and the classification of tempers. Buyers should request the specific standard certificate (chemical and mechanical) relevant to the supply region to verify compliance with application-specific demands.

Corrosion Resistance

EN AW-1050A exhibits excellent general corrosion resistance in atmospheric and mildly corrosive environments due to the rapid formation of a tenacious, self-healing aluminium oxide film. In many indoor and rural outdoor applications the alloy shows long service life without additional coatings. Resistance to pitting is modest compared with higher-alloyed 5xxx or 6xxx series in aggressive chloride environments; surface finish and alloy purity help mitigate localized attack.

In marine environments 1050A performs acceptably for many components provided design minimizes crevice formation and avoids contact with more noble metals without isolation. The alloy is not highly susceptible to stress-corrosion cracking in the annealed condition, but highly strained zones (cold-worked) combined with aggressive environments can raise SCC risk. When exposed to dissimilar metals, EN AW-1050A will act anodic relative to many steels and copper alloys, so galvanic coupling should be addressed with insulating layers or sacrificial design considerations.

Compared with the 5xxx series (Mg-containing), 1050A offers superior electrical conductivity and somewhat better ease of forming but lower strength and, in some chloride-rich conditions, lower pitting resistance. Compared with heat-treatable 6xxx and 7xxx series alloys, 1050A is much more corrosion resistant in general atmospheres but lacks the peak strength those alloys can provide.

Fabrication Properties

Weldability

EN AW-1050A welds readily by TIG and MIG/GMAW with minimal porosity when proper cleaning and joint fit-up are observed. Recommended filler alloys are high-purity aluminium fillers such as 1100 or 4043/5356 depending on the required joint strength and corrosion performance; fillers with higher silicon or magnesium content modify joint strength and weld bead appearance. Hot-cracking risk is low for 1050A because of its simple chemistry and wide solidification range, but contamination, poor gas shielding and rapid cooling practices can introduce defects.

Machinability

Machinability of EN AW-1050A is moderate to fair; the alloy machines well compared with many steels but is softer than many alloyed aluminium grades, which can produce built-up edge and less favorable chip control. Carbide tooling with positive rake angles and high-speed coatings is recommended for aggressive machining of thicker sections; turn and drill speeds should be adjusted to avoid smearing and to achieve good surface finish. Dimensional control is straightforward due to homogeneous microstructure, but allowances should be made for spring-back in forming operations.

Formability

Formability is one of the alloy’s strongest attributes; O temper material supports deep drawing, spinning and complex bending with very small bend radii relative to alloyed materials. Recommended minimum bend radii and stretch-forming limits depend on gauge and temper, but general shop practice uses R/t ratios lower than for 3xxx or 5xxx alloys. Cold work increases springback and reduces allowable strain before cracking, so designers typically specify annealed (O) material for demanding forming sequences.

Heat Treatment Behavior

Because EN AW-1050A is a non-heat-treatable alloy, conventional solution treatment and artificial aging do not produce significant precipitation strengthening. Thermal cycling at elevated temperatures can anneal cold-worked product, so stress-relief annealing and full annealing are the primary thermal processes used to alter mechanical properties. Typical annealing for softening is performed in the range of approximately 350–415 °C for controlled times dependent on section thickness, followed by slow cooling to achieve the O temper.

Work hardening (cold working) is the principal commercial method to increase strength; strain can be introduced by rolling, drawing or stamping to move the material into H-temper designations. Partial annealing or recovery treatments can be used to tailor a trade-off between strength and ductility where forming operations require intermediate properties. Careful control of thermal exposure during fabrication is essential because unintended overaging (recrystallization/annealing) will remove the benefits of strain hardening.

High-Temperature Performance

EN AW-1050A experiences progressive strength reduction as temperature rises; above approximately 100–150 °C the yield and tensile strengths drop significantly compared with room temperature values. For sustained elevated temperature service, designers typically limit continuous operating temperatures to moderate levels and prefer alloys with alloying additions that retain strength at temperature. Oxidation is limited to formation of a stable aluminium oxide film; catastrophic oxidation is not a concern but surface scale can affect thermal contact and emissivity.

In welded or heat-affected zones, the absence of precipitate-strengthening means there is little hardening to be lost, but local annealing of work-hardened regions will soften and reduce residual stresses introduced by fabrication. For short-term elevated temperature excursions, 1050A will maintain dimensional stability provided thermal cycles are controlled and differential expansion with adjacent materials is accommodated.

Applications

Industry	Example Component	Why EN AW-1050A Is Used
Electrical	Bus bars, conductors, electrode strips	High electrical conductivity and ease of forming
Marine / Chemical	Tanks, piping components, fittings	Excellent corrosion resistance and weldability
Architecture / Lighting	Reflectors, decorative panels, cladding	High reflectivity, surface finish and formability
Packaging / Food	Foil, containers, packaging laminates	Purity and corrosion resistance for food contact
Electronics / Thermal	Heat sinks, thermal spreaders	High thermal conductivity and low density

EN AW-1050A is frequently the material of choice when designers prioritize conductivity and formability with adequate corrosion resistance, and when the component geometry favors thin-gauge or extensively formed parts. The alloy’s combination of attributes translates to cost-effective manufacturing and predictable in-service behavior for a wide range of conservative engineering designs.

Selection Insights

When selecting EN AW-1050A, choose it if the primary requirements are maximum electrical or thermal conductivity, exceptional formability, gentle corrosion environments and low material cost. Specify annealed (O) temper for deep drawing or severe forming, and select appropriate H-tempers only when modest increases in strength are needed without sacrificing weldability.

Compared with commercially pure 1100, 1050A typically trades a small amount of conductivity and formability for slightly improved surface quality and controlled impurity limits; both alloys are close, but 1050A may be specified where tighter impurity control is needed. Compared with work-hardened alloys such as 3003 or 5052, EN AW-1050A offers superior conductivity and often better forming ability but lower strength and lower resistance to certain forms of localized corrosion. Compared with heat-treatable alloys such as 6061 or 6063, 1050A is chosen when corrosion resistance, conductivity and formability trump the need for high peak strength; it is a practical low-cost alternative where strength-to-weight does not drive the design.

Closing Summary

EN AW-1050A remains a fundamental engineering aluminium for applications demanding high conductivity, excellent formability and robust corrosion resistance in a low-cost, widely available material form; its predictable behavior under forming, welding and thermal exposure makes it a reliable choice for many conservative design solutions.