Aluminum A3003: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

A3003 is an aluminum-manganese alloy from the 3xxx series, where manganese is the principal alloying element providing solid-solution strengthening and improved work hardening response. It is categorized as a non-heat-treatable alloy; strength is gained predominantly through cold working rather than precipitation heat treatment.

Key traits for A3003 include moderate strength, very good formability, acceptable corrosion resistance in many atmospheres, and good weldability with standard aluminum processes. Typical industries that use A3003 are building and construction (guttering, roofing, cladding), HVAC and heat-exchange equipment, kitchenware and cookware, and general sheet-metal fabrication where low cost and high ductility are required.

Engineers often choose A3003 when a balance of formability and corrosion resistance is needed at a lower material cost than many alloyed or heat-treatable aluminums. Its combination of ductility, stable mechanical behavior after cold working, and broad availability in sheet and coil makes it preferable to very soft 1xxx alloys when extra strength is needed without sacrificing forming performance.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (30–45%)	Excellent	Excellent	Fully annealed condition; best for deep drawing
H12	Low-Medium	Medium-High (20–30%)	Very Good	Excellent	Slight work-hardening, retains good formability
H14	Medium	Medium (12–20%)	Good	Excellent	Typical commercial temper for moderate strength
H16	Medium-High	Lower (8–15%)	Fair-Good	Excellent	Increased strength via cold work
H18	High	Low (3–8%)	Fair-Poor	Excellent	Full hard; used where stiffness and strength are prioritized
H22	Low-Medium (stabilized)	Medium-High (20–30%)	Very Good	Excellent	Strain-hardened and partially annealed (stabilized)

Tempers in the 3xxx family are achieved by controlled amounts of cold working and occasional stabilizing anneals rather than by solution and aging. As the H-number increases, tensile and yield strengths rise due to dislocation density increase while ductility and formability fall due to strain hardening.

For fabrication, designers select O or low-H tempers for deep drawing and operations requiring large plastic strains, and H14–H18 tempers for parts that need higher as-formed stiffness and dimensional stability after forming.

Chemical Composition

Element	% Range	Notes
Si	0.0–0.6	Deoxidizer; limits kept low to preserve ductility
Fe	0.0–0.7	Impurity; affects strength and surface finish
Mn	0.8–1.5	Primary alloying element; provides solid-solution strengthening
Mg	0.0–0.2	Minor; small Mg can slightly increase strength
Cu	0.0–0.2	Typically low; excessive Cu reduces corrosion resistance
Zn	0.0–0.1	Trace; kept low to avoid galvanic sensitivity
Cr	0.0–0.1	Trace; controls grain structure in some melts
Ti	0.0–0.15	Grain refiner in cast/ingot production
Others (each)	0.0–0.05	Combined others typical max ~0.15%; balance Al

The manganese level is the defining characteristic of A3003, creating a stronger solid solution than commercially pure aluminum and enabling significant strengthening by cold work. Trace elements and impurities influence surface finish, recrystallization behavior, and corrosion tendencies; manufacturers control these to meet sheet and coil specification limits.

Mechanical Properties

A3003 displays ductile tensile behavior with a clear strain-hardening region in tension curves for cold-worked tempers. In annealed condition the alloy yields at very low stress and shows long uniform elongation, while H-tempered product exhibits higher yield and ultimate tensile strength with reduced uniform elongation.

Hardness scales with temper and correlated with tensile properties; Brinell or Vickers hardness increases substantially from O to H18 as dislocation density rises. Fatigue performance is moderate and strongly dependent on surface finish, cold work level, and presence of notches; cold-worked tempers generally show improved fatigue strength at the expense of ductility.

Thickness affects strength and formability: thinner gauges generally allow tighter bend radii and higher apparent formability, while thicker sections can show higher allowable bending stresses but reduced uniform elongation and more pronounced springback behavior.

Property	O/Annealed	Key Temper (H14)	Notes
Tensile Strength (MPa)	95–125	140–180	Values vary with thickness and temper; H14 typical commercial target
Yield Strength (MPa)	30–70	90–120	Yield increases markedly with cold work
Elongation (%)	30–45	10–20	Elongation decreases as temper hardens
Hardness (HB)	30–45	50–70	Hardness correlates with tensile strength and cold work level

Physical Properties

Property	Value	Notes
Density	2.70–2.73 g/cm³	Standard aluminum density; varies negligibly with alloying
Melting Range	~640–655 °C	Solidus to liquidus range; melting behavior like typical Al-Mn alloys
Thermal Conductivity	~120–150 W/m·K	High thermal conductivity suitable for heat exchange applications
Electrical Conductivity	~30–40 %IACS	Lower than pure Al due to Mn and other solutes
Specific Heat	~0.90 J/g·K (900 J/kg·K)	Typical of aluminum alloys at ambient temperatures
Thermal Expansion	~23–24 ×10⁻⁶ /K (20–100°C)	Similar to other wrought aluminum alloys

A3003 retains most of the desirable physical properties of aluminum base metal such as low density and high thermal conductivity, while sacrificing some electrical conductivity to the Mn additions. Thermal expansion and specific heat are comparable to other commercial alloys and must be considered for joined-component design and thermal cycling applications.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2–6.0 mm	Wide range depending on temper	O, H12, H14, H16	Used for roofing, gutters, cookware, ductwork
Plate	>6 mm (limited uses)	Similar strength trends; thicker sections reduce formability	H14–H18	Less common; used when thicker stiff panels required
Extrusion	Profiles up to large cross-sections	Strength increases with cold working or work-hardening	H14/H16 (after forming)	3003 can be extruded but 6xxx more common for structural extrusions
Tube	Diameter 10–200+ mm	Cold-drawn tubes exhibit higher strength	H14, H18	Used for HVAC, low-pressure fluid handling
Bar/Rod	Small diameters	Strength depends on drawing	H18 for high-strength rod	Used in fasteners, rivets, small fabrications

Sheets and coils are the primary commercial forms for A3003 due to its application emphasis on fabricated panels and formed parts. Extrusion of 3003 is feasible but many structural extrusions use 6063/6061 for improved mechanical properties; nevertheless 3003 extrusions are chosen where formability and corrosion resistance are priorities. Processing differences—cold rolling, tempering, surface finish, and anneal cycles—control final gauge, texture, and mechanical balance tailored to end-use.

Equivalent Grades

Standard	Grade	Region	Notes
AA	A3003	USA	Primary designation used in UNS/AA standards
EN AW	EN AW-3003	Europe	Equivalent under EN 573; similar chemical limits
JIS	A3003	Japan	JIS uses similar numbering; chemical and mechanical spec limits may differ slightly
GB/T	3A21 (commonly mapped)	China	GB/T 3880 and other standards map 3003 to Chinese designations such as 3A21

Standard equivalents generally map closely on main Mn content and use similar temper nomenclature (O, Hx). Subtle differences arise in maximum impurity limits, definition of temper mechanical test conditions, and surface finish / surface treatment acceptance which can affect selection for highly regulated applications or cross-border procurement.

Corrosion Resistance

A3003 provides good general atmospheric corrosion resistance due to the protective oxide film that rapidly forms on aluminum surfaces. It performs well in urban and rural atmospheres and resists staining and oxidation, making it a frequent choice for gutters, roofing, and exterior architectural panels.

In marine environments A3003 is acceptable for many offshore and near-shore applications but is generally less resistant to localized pitting and crevice corrosion than higher-magnesium 5xxx series alloys. Prolonged exposure to chloride-rich environments calls for protective coatings, isolation from dissimilar metals, or selection of a more marine-optimized alloy.

The alloy exhibits low susceptibility to classical stress corrosion cracking because it is non-heat-treatable and has limited solute concentrations that promote SCC. Galvanic coupling to more noble metals (copper, stainless steels) can accelerate local attack; designers should electrically isolate joints and specify appropriate coatings or sacrificial anodes where dissimilar-metal contact is unavoidable. Compared with 1xxx series, A3003 trades slightly reduced conductivity for improved mechanical strength, and compared with 5xxx series it generally trades some marine corrosion resistance for better formability and lower cost.

Fabrication Properties

Weldability

A3003 welds readily with common processes such as MIG (GMAW) and TIG (GTAW) using 4xxx-series aluminum-silicon filler alloys where enhanced fluidity and strength are desired. Solid-state joining methods and spot welding are also effective on thin gauges; preheating is generally unnecessary for small parts but may be used to reduce distortion. HAZ softening is limited because the alloy is non-heat-treatable, but local annealing will restore ductility and reduce strength in cold-worked regions, which must be considered in design.

Machinability

Machining 3003 is of moderate difficulty; its ductility can lead to long, gummy chips unless tooling geometry and feeds are optimized. Carbide tooling with positive rake and interrupted cut strategies reduce built-up edge and improve surface finish. Recommended cutting speeds and feeds are conservative compared with steels; coolant and chip evacuation are important to control workpiece temperature and maintain dimensional accuracy.

Formability

A3003 is one of the more formable alloy grades in commercial use; it supports deep drawing, spinning, bending, and stretch forming in annealed or lightly strain-hardened conditions. Minimum bend radii depend on temper and thickness but typical design practice specifies 1–2× thickness for H14 and 0.5–1× thickness for O temper depending on tooling. For parts requiring severe forming, start with O temper and then draw or form, followed by controlled strain-hardening or stabilizing anneal if higher in-service strength is needed.

Heat Treatment Behavior

A3003 is non-heat-treatable in the precipitation-hardening sense; solution heat treatment and artificial aging do not produce significant strengthening. Typical industrial practice relies on cold work (strain hardening) to raise strength and hardness, with tempering achieved by controlled amounts of mechanical deformation.

Annealing (full or partial) is used to restore ductility and recrystallize the microstructure after heavy cold work; temperatures for anneal are in the range 300–415 °C depending on desired recrystallization and grain growth effects. Stabilizing treatments such as partial anneals (H22) are used when some recovery is desired without returning fully to the soft O condition.

High-Temperature Performance

At elevated temperatures A3003 experiences progressive loss of yield and tensile strength; service temperatures above ~150 °C lead to measurable strength reduction, with significant softening above ~200 °C. Oxidation resistance remains acceptable due to the stable Al2O3 surface film, but creep resistance is poor compared with heat-treatable or high-strength alloys and is not recommended for long-term structural loading at elevated temperature.

Welded joints in A3003 are not prone to long-term high-temperature embrittlement, but transient heating during welding can locally anneal cold-worked zones and alter mechanical properties, which must be addressed through design margins or post-weld mechanical processing if necessary.

Applications

Industry	Example Component	Why A3003 Is Used
Building & Construction	Gutters, roofing, cladding	Excellent formability, corrosion resistance, cost-effectiveness
HVAC / Heat Exchange	Ductwork, fins	High thermal conductivity and ease of forming thin fins
Consumer Goods / Kitchenware	Cookware, baking trays	Good thermal behavior, formability, and sanitary surface
Transportation	Fuel tanks (non-critical), interior panels	Moderate strength and formability at low cost
Industrial Equipment	Storage tanks, chimneys	Corrosion resistance and fabricability for large panels

A3003’s combination of formability, weldability, and corrosion resistance makes it a mainstay for sheet-metal components where severe structural loads are not the governing design driver. Its low cost and wide availability in sheet and coil form factor further drive selection across multiple industries.

Selection Insights

Choose A3003 when you need an economical alloy with superior formability and good atmospheric corrosion resistance while accepting moderate strength compared with heat-treatable alloys. It is an excellent default for deep drawing and formed sheet-metal parts where welding and surface appearance are important.

Compared with commercially pure aluminum (1100), A3003 offers higher strength with only a moderate penalty in electrical conductivity and similar formability, making it preferable for structural sheet applications. Versus other work-hardened alloys such as 5052, A3003 typically has comparable formability but slightly lower strength and slightly reduced marine corrosion resistance; select 5052 for magnesium-enhanced marine performance. Against heat-treatable alloys like 6061 or 6063, pick A3003 when forming and cost are prioritized over peak strength; 6061 delivers higher structural strength where aging can be used, while 3003 remains easier to shape and less expensive.

Closing Summary

A3003 remains relevant in modern engineering because it provides a cost-effective balance of ductility, weldability, and corrosion resistance for sheet-metal fabrication and formed parts. Its non-heat-treatable strengthening route via cold work simplifies processing for many manufacturers and delivers predictable, stable mechanical behavior across common tempers.