Aluminum 3003: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

3003 is a member of the 3xxx series of wrought aluminum alloys, characterized by manganese as the principal alloying addition. The 3xxx family is non-heat-treatable and strengthens primarily by solid-solution effects and strain hardening, with 3003 depending on Mn additions to provide a balance of strength and workability.

The alloying mix is dominated by manganese (approx. 1.0–1.5%), with small controlled copper content and low levels of silicon and iron. This chemistry produces moderate strength above commercially pure aluminum, good corrosion resistance, excellent formability in soft tempers, and reliable weldability, making it an all-purpose alloy for sheet and extrusion applications.

3003 is widely used in HVAC, cookware, chemical handling, architectural cladding, and general sheet-metal work where formability and corrosion resistance are critical. Engineers select 3003 when they need a stronger alternative to 1000-series pure aluminum without requiring heat-treatable strength increases, and when fabrication operations include bending, stamping, and welding.

Compared with heat-treatable alloys, 3003 sacrifices peak tensile and yield strength but gains consistent workability and lower susceptibility to quench-related distortion. Its widespread availability and low cost relative to specialty alloys further drive specification in high-volume and commodity applications.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (20–40%)	Excellent	Excellent	Fully annealed, best for deep drawing and forming
H12	Moderate	Moderate (10–20%)	Good	Excellent	Light cold work, slight strength increase over O
H14	Medium	Moderate-low (6–12%)	Good	Excellent	Quarter-hard; common for stamping and moderate forming
H16	Medium-High	Low (4–8%)	Fair	Excellent	Half-hard; used where greater rigidity is required
H18	High	Low (1–6%)	Limited	Excellent	Full-hard; used for applications requiring high stiffness

Temper markedly alters 3003 performance through cold work rather than precipitation mechanisms. Annealed (O) material provides maximum ductility and formability for deep-draw and bending operations, while H tempers increase strength by strain hardening at the expense of elongation and some formability.

Selection of temper is a direct trade-off between ease of fabrication and end-use stiffness or yield requirements. Weldability remains excellent across tempers because strengthening is not heat-treatment dependent, but localized softening in the HAZ can slightly reduce strength adjacent to welds.

Chemical Composition

Element	% Range	Notes
Si	≤ 0.6	Controlled to limit brittle intermetallics and maintain formability
Fe	≤ 0.7	Common impurity; excess reduces ductility and increases anisotropy
Mn	1.0–1.5	Principal alloying element providing strain-hardening strength
Mg	≤ 0.1	Typically residual; not a major strengthening agent in 3003
Cu	0.05–0.20	Small addition to raise strength and modify mechanical behavior
Zn	≤ 0.1	Kept low to avoid detrimental galvanic behavior and brittleness
Cr	≤ 0.05	Usually residual; can affect grain structure if present
Ti	≤ 0.15	Occurs as impurity or deoxidizer; may be present in trace amounts
Others (each)	≤ 0.05	Residuals; aluminium balance by difference

Manganese is the purposeful alloying element that stabilizes a higher strength level via solid-solution strengthening and refined grain structure. Copper modestly increases strength and can slightly reduce corrosion resistance if present in the upper end of the specification.

Silicon and iron are controlled to minimize brittle phases and to maintain good surface quality and forming behavior. The balance of these elements is tuned to favor cold work response rather than heat-treatable precipitation.

Mechanical Properties

Tensile behavior in 3003 is typical of strain-hardened, non-heat-treatable alloys: properties scale with temper and amount of cold work. In annealed condition the alloy exhibits low yield and modest ultimate strength with high elongation, enabling deep drawing and complex forming. As tempers progress from H12 to H18, yield and tensile strengths rise while elongation and bendability decrease predictably.

Hardness increases with cold work and correlates with tensile properties; hardness is typically low in O and rises through the H-series. Fatigue performance is moderate and highly dependent on surface condition, cold work, and residual stresses introduced by forming and welding. Thicker sections can show slightly improved fatigue life due to lower notch sensitivity but may be less formable and harder to stamp.

Work hardening rate and thickness influence final ductility and springback. Thin gauge sheet is more easily formed to tight radii, while thicker plate or heavy extrusions resist forming and require more force or higher tempers. Welding introduces localized soft zones but typically does not induce significant embrittlement because precipitation hardening is not used in this alloy.

Property	O/Annealed	Key Temper (H14)	Notes
Tensile Strength	110–155 MPa (16–22 ksi)	160–220 MPa (23–32 ksi)	Tensile increases with cold work; ranges are typical for common tempers
Yield Strength	35–70 MPa (5–10 ksi)	120–170 MPa (17–25 ksi)	Yield increases significantly in H tempers due to strain hardening
Elongation	20–40%	6–12%	Ductility declines substantially with increased cold work
Hardness (HB)	25–45	40–80	Hardness roughly correlates with tensile strength and temper level

Physical Properties

Property	Value	Notes
Density	2.73 g/cm³	Typical for aluminum alloys; useful for mass and weight calculations
Melting Range	~ 645–660 °C	Narrow melting range with no discrete eutectic; important for soldering/welding
Thermal Conductivity	~ 120–160 W/m·K	Lower than pure Al but still excellent for heat spreading
Electrical Conductivity	~ 30–40 % IACS	Reduced versus 1000-series due to alloying; adequate for low-voltage conductors
Specific Heat	~ 900 J/kg·K	Similar to other Al alloys; important for thermal mass calculations
Thermal Expansion	~ 23–24 µm/m·K	Typical aluminum coefficient; design for thermal strain in assemblies

The density and thermal properties make 3003 attractive where low mass and good thermal transport are required, such as heat exchangers and cookware. Electrical conductivity is reduced compared to commercially pure grades but remains sufficient for certain electrical and EMI applications where mechanical strength is prioritized.

Thermal expansion must be accounted for in joints with dissimilar materials to prevent distortion or seal failure. The melting range and thermal conductivity also affect welding practice and heat input control to limit HAZ softening.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2–6.0 mm	Strength scales with temper; thin gauges form easily	O, H14, H16	Widely used for panels, roofing, and appliances
Plate	>6.0 mm	Less formable; higher residual strength in H tempers	H16, H18	Used where stiffness and wear resistance are required
Extrusion	Profiles up to several meters	Strength depends on extrusion and tempering/cold work	O, H12, H14	Complex cross-sections for architectural and structural elements
Tube	Diameters from small to large	Wall thickness affects stiffness and collapse resistance	O, H14	Used for HVAC, conduit, and lightweight framing
Bar/Rod	Diameters 3–100 mm	Typical wrought strength with varying cold work	H14, H18	Used for machined parts and fasteners where formability is less critical

Sheets are the most common commercial product for 3003, supplied in coils and cut lengths for stamping and roll-forming. Extruded sections are used where custom profiles are required, and they may be delivered in softer tempers to allow post-extrusion forming.

Plate and heavy sections are less common due to limited formability and higher processing cost, but they are selected for structural stiffness or where machining and joining are primary fabrication routes. Tubes and rods serve niche mechanical and fluid handling roles where corrosion resistance and moderate strength are needed.

Equivalent Grades

Standard	Grade	Region	Notes
AA	3003	USA	ASTM/AA designation; common reference in North America
EN AW	3003	Europe	EN AW-3003 broadly equivalent; check local tempers and tolerances
JIS	A3003	Japan	Often labeled A3003; verify impurity limits vs AA spec
GB/T	3A21 (approx.)	China	3A21 is frequently used as the Chinese equivalent, with minor compositional tolerances

Equivalent naming across standards generally maps the alloy chemistry but differences in impurity limits, temper definitions, and surface finish requirements can affect interchangeability. Engineers should verify mechanical property tables and specification limits for the relevant standard when substituting material sourced from different regions.

Procurement and certification language in contracts should specify the applicable standard and required mechanical/chemical tests to avoid subtle mismatches between regional variants.

Corrosion Resistance

3003 demonstrates good general atmospheric corrosion resistance due to the aluminum oxide passive film and the relatively low content of copper and zinc. It resists oxidizing environments and urban atmospheres effectively, making it a common choice for building facades, ductwork, and outdoor enclosures.

In marine environments 3003 is acceptable for many structural and decorative applications but is not as resistant as highly alloyed marine-specific grades like 5083 or 5086. Prolonged immersion in seawater or chloride-rich conditions can promote pitting; protective coatings or sacrificial anodes are recommended for long-term service.

Stress corrosion cracking is not a significant concern for 3003 because it is not a high-strength, heat-treatable alloy; however, high residual stresses combined with aggressive environments can still induce localized failures. Galvanic interactions with dissimilar metals must be managed, as aluminum will be anodic against common steels and copper, requiring isolation or coating to prevent accelerated corrosion.

Compared to 1xxx series alloys, 3003 offers improved strength while maintaining comparable corrosion resistance. Compared to 5xxx and 6xxx series alloys, 3003 typically provides lower strength but similar or slightly lower marine corrosion resistance depending on exact alloying and environment.

Fabrication Properties

Weldability

3003 welds readily by TIG, MIG (GMAW), and resistance processes because it is not precipitation-strengthened. Use of standard aluminum filler metals such as ER4043 (Al-Si) or ER5356 (Al-Mg) is common; ER4043 gives excellent fluidity and lower porosity risk, while ER5356 provides higher strength in the weld. Hot-cracking risk is low but can increase with poor cleaning, excessive joint restraint, or improper filler selection; control heat input and cleanliness to minimize porosity.

Weld heat-affected zones will soften when joining H-tempers to O but will not produce precipitation-hardening effects. Post-weld mechanical properties are primarily controlled by parent metal temper and filler selection; consider mechanical testing of weld samples for critical structural applications.

Machinability

3003 has fair machinability but is not considered a free-cutting alloy; machining rates are moderate and benefit from rigid setups and sharp carbide tooling. It produces ductile, continuous chips that can adhere to tooling if cutting speeds and feeds are not optimized; chip breakers and positive rake geometries help manage swarf.

Tool wear is moderate due to aluminum’s tendency to gall; use of lubricants, coated carbide, or high-speed steel with appropriate geometries improves tool life. Drill and endmill speeds should be set for aluminum with high feed and relatively low spindle speeds to prevent built-up edge.

Formability

Formability is a key strength of 3003, especially in the O temper, where deep drawing and bending to tight radii are readily achievable. Minimum bend radii depend on gauge and temper, but O temper often allows radii as low as 0.5–1.0× thickness for many operations, while H14/H16 will require larger radii and may need annealing for severe forming.

Cold working increases strength while reducing ductility; intermediate anneals (O) can restore formability after heavy deformation. For complex stamping sequences, plan for appropriate springback compensation based on temper and gauge.

Heat Treatment Behavior

3003 is a non-heat-treatable alloy and therefore does not respond to solution treatment and artificial aging for strengthening. Attempts to apply typical solution and aging cycles used for 6xxx or 7xxx series will not produce precipitation hardening in 3003; properties are controlled by composition and cold work.

Control of properties is achieved through work hardening and annealing cycles. Full anneal (O) is accomplished by heating to a specified temperature range followed by controlled cooling to restore ductility, while incremental tempers (H12–H18) are created by defined cold-work levels and, in some cases, stabilization treatments like H112.

Because strengthening is mechanical rather than metallurgical, components that require local hardening or selective strengthening generally use cold work or localized mechanical treatments rather than global heat treatments.

High-Temperature Performance

3003 experiences gradual strength loss with increasing temperature typical of aluminum alloys; above approximately 150–200 °C the yield and tensile strengths decline measurably. Long-term exposure above 200 °C is generally not recommended for load-bearing applications because creep and softening accelerate.

Oxidation at elevated temperatures is limited because of the protective alumina scale, but surface discoloration and scaling can occur at high temperatures or in aggressive atmospheres. Weld zones exposed to heat can show HAZ softening but do not undergo temper transformations common to heat-treatable alloys.

Thermal cycling and differential expansion with attached dissimilar materials should be considered in design to prevent fatigue and joint loosening. For sustained high-temperature service, select alloys specifically designed for elevated temperature strength.

Applications

Industry	Example Component	Why 3003 Is Used
HVAC	Ductwork and coils	Good formability and corrosion resistance for air handling
Appliances	Cookware, oven panels	Thermal conductivity and formability for drawn shapes
Building/Architectural	Cladding, soffits	Weathering resistance and ease of fabrication
Chemical/Process	Tanks, piping components	Corrosion resistance to many chemicals and ease of welding
Electrical/Heat Transfer	Heat sinks, radiators	Thermal conductivity combined with adequate strength

3003 remains a workhorse alloy in many industries because of its balance of formability, corrosion resistance, and cost-effectiveness. Its predictable cold-work response and widespread availability in sheet, coil, and extruded forms make it an economical choice for high-volume fabrication.

Selection Insights

Choose 3003 when you need better strength than commercially pure aluminum (1000-series) while retaining excellent formability and corrosion resistance. Compared with 1100, 3003 trades some electrical and thermal conductivity for a meaningful increase in mechanical strength and improved resistance to deformation during forming.

Against nearby work-hardened alloys such as 5052, 3003 typically offers easier formability and comparable corrosion resistance but lower strength; 5052 is preferred when higher strength and better marine corrosion resistance are required. When compared with heat-treatable alloys like 6061 or 6063, 3003 is selected for fabrication processes requiring extensive forming and welding where peak strength is not critical and cost and ductility are prioritized.

For procurement, prioritize temper selection and supplier certification over nominal alloy number when formability or weld strength is critical. If higher strength is required after forming, consider mechanical cold work or migrating to an alloy with higher intrinsic strength and acceptable fabrication trade-offs.

Closing Summary

3003 is a versatile, Mn-enriched aluminum alloy that fills the niche between pure aluminum and higher-strength, heat-treatable alloys by offering balanced strength, excellent formability, and reliable corrosion resistance. Its non-heat-treatable nature simplifies fabrication choices and makes it a cost-effective, widely available material for sheet, extrusion, and formed components across numerous industries.