Aluminum EN AW-3004: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

EN AW-3004 is a 3xxx-series aluminum alloy (Al-Mn-Mg family) classified in the wrought aluminum-manganese alloys. It is a non-heat-treatable alloy where manganese is the principal alloying addition and magnesium is used to raise strength relative to AA3003/3000 base alloys. The alloy is strengthened primarily by strain hardening (work-hardening) during cold working, with limited contribution from solid-solution strengthening by Mg and Mn. Typical traits include moderate-to-good strength for a non-heat-treatable alloy, good corrosion resistance in many atmospheric environments, excellent formability in annealed conditions and reasonable weldability in common arc processes.

Key industries for EN AW-3004 include packaging (particularly can and container stock), HVAC and building envelope components, architectural trim, and general sheet-formed components used in appliances and small structural elements. Engineers select 3004 when they need better strength than pure and 3003 alloys while retaining deep-draw and roll-forming ability required for thin-gauge applications. The alloy is often chosen over higher-strength heat-treatable alloys when formability, surface finish, and corrosion resistance are more critical than peak tensile strength or when post-form heat treatment is impractical.

EN AW-3004 is favored for sheet and coil manufacture because its combination of Mn and Mg provides a good balance of strength increment and retained ductility, enabling processes like deep drawing, ironing and complex bending. It fills a practical niche between pure aluminum (excellent formability but low strength) and 5xxx-series or 6xxx-series alloys (higher strength but different forming and corrosion trade-offs), making it a workhorse for rolled-product applications.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (20–35%)	Excellent	Excellent	Fully annealed condition for maximum ductility
H12	Moderate	Low (3–8%)	Limited	Good	Partial hardening (moderate formability)
H14	Moderate-High	Moderate (6–12%)	Good	Good	Quarter-hard cold work, common for sheet applications
H16	High	Low (3–8%)	Limited	Good	Half-hard condition for higher strength
H18	Very High	Low (2–6%)	Poorer	Good	Full hard, highest cold-worked strength
H24	Moderate-High	Moderate (6–12%)	Good	Good	Strain-hardened and partially annealed/stabilized

Temper strongly controls the mechanical trade-offs between strength and ductility: annealed O temper delivers the best forming characteristics for deep drawing and complex deformation, whereas H- tempers produced by controlled cold work progressively raise yield and tensile strength at the expense of elongation. Welded joints typically require post-weld mechanical considerations because H-tempers will locally soften in the heat-affected zone, so selection of temper must consider downstream forming and welding operations.

Chemical Composition

Element	% Range	Notes
Si	≤ 0.6	Impurity element; reduces melt fluidity at high contents
Fe	≤ 0.7	Intermetallic-forming impurity that affects surface finish
Mn	1.0–1.5	Principal alloying element for strength and recrystallization control
Mg	0.8–1.3	Solid-solution strengthening contributor; increases strain-hardening response
Cu	≤ 0.2	Typically low; higher Cu reduces corrosion resistance
Zn	≤ 0.2	Minor, kept low to avoid adverse effects on corrosion
Cr	≤ 0.1	Usually not intentionally added; small amounts control grain structure
Ti	≤ 0.15	Grain refiner when present in small quantities
Others (each)	≤ 0.05; total ≤ 0.15	Residual and trace elements

The composition gives 3004 its characteristic behavior: manganese refines grain structure and improves strength without serious loss of ductility, while magnesium increases yield and tensile strength through solid-solution effects and enhanced work-hardening response. Controlled limits of Fe and Si are maintained to preserve surface quality and to limit brittle intermetallics that can reduce formability and finish for decorative or can-stock applications.

Mechanical Properties

EN AW-3004 displays a tensile/yield profile that is strongly temper-dependent, with annealed sheet showing high elongation and lower yield, and hard H-tempers providing significantly increased yield and tensile strength. In rolled and cold-worked tempers, the alloy exhibits good uniform elongation for thin gauges used in deep drawing but reduced total elongation in fully hard conditions; the strain-hardening exponent (n-value) is favorable for stretch forming in O and partially hardened tempers. Hardness tracks with tensile strength; typical Brinell or Rockwell values move upward with cold work but remain below those of heat-treatable alloys.

Fatigue performance of 3004 is typical for Al-Mn alloys: baseline endurance is moderate and is sensitive to surface finish, gauge, and residual stresses induced by forming or welding. Thicker sections and heavier cold work can introduce anisotropy and localized microstructural features that influence crack initiation. Thickness influences mechanical properties primarily through work-hardening path during rolling and the ensuing grain structure; thin-gauge sheet attains higher working strains in rolling, affecting strength and ductility balance.

Property	O/Annealed	Key Temper (H14/H18)	Notes
Tensile Strength (MPa)	120–160	200–270	Values vary with gauge and cold-work level
Yield Strength (MPa)	40–80	120–190	Yield rises substantially with H-tempers
Elongation (%)	20–35	2–12	High in O for deep drawing; low in H18 for stiff sections
Hardness (HB)	25–45	50–85	Brinell hardness increases with degree of cold work

Physical Properties

Property	Value	Notes
Density	2.73 g/cm³	Typical for Al-Mn alloys; relevant for mass-sensitive design
Melting Range	640–655 °C	Solidus–liquidus range approximately in this band
Thermal Conductivity	~130–160 W/m·K	Lower than pure Al due to alloying elements
Electrical Conductivity	~30–36 %IACS	Reduced from pure Al; affected by cold work and composition
Specific Heat	~900 J/kg·K	Near that of pure aluminum, temperature dependent
Thermal Expansion	23–24 µm/m·K (20–100 °C)	Typical linear thermal expansion coefficient for wrought Al alloys

EN AW-3004 retains favorable thermal conductivity compared with many structural metals, making it useful in applications where heat spreading is needed while still providing formability and corrosion resistance. Electrical conductivity is reduced by alloying and cold work, so 3004 is not chosen where electrical performance is critical, but it remains adequate for many bonded or earthed enclosure applications.

Thermal expansion and specific heat are important in design when joining dissimilar materials or when dimensional tolerances across temperature cycles are tight. The relatively high coefficient of thermal expansion compared with steels must be accounted for in fastener and joint design.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2–4.0 mm	Work-hardens during rolling; thin gauges often in H14/H18	O, H14, H18	Widely used for coil, stampings, can stock
Plate	>4.0 mm	Lower work-hardening per pass; commonly supplied annealed or light-hardened	O, H12	Less common than sheet; used for thicker structural panels
Extrusion	Various profiles	Strength depends on post-extrusion cold work	O, H14	Limited extrusion use compared with 6xxx alloys
Tube	0.3–5.0 mm wall	Cold-drawn tubes can be supplied in H18/H24	O, H14, H18	Used for HVAC duct, condensers, decorative tubing
Bar/Rod	≤ 50 mm dia	Mechanical properties vary with cold-drawn condition	O, H14	Less common, used for small profiles and fasteners

Processing differences between sheet/coil and extrusions are significant: sheet is predominantly cold-rolled and can be produced to very tight thickness tolerances and surface finishes, whereas extrusions require different alloy tuning and typically favor 6xxx series for dimensional stability. For 3004, sheet/coil production and cold forming are central; extrusions and heavy sections are less common due to lower strength-to-weight compared with heat-treatable alloys and different recrystallization characteristics.

Product form dictates downstream operations: thin-gauge sheet in O temper enables deep drawing and ironing, while H-tempers are best for panels where dimensional stability and stiffness are required without subsequent heavy forming.

Equivalent Grades

Standard	Grade	Region	Notes
AA	3004	USA	Widely used designation in North America
EN AW	3004	Europe	Identical EN naming for wrought alloy family
JIS	A3004 (approx)	Japan	Equivalent family designation; check local JIS spec for exact limits
GB/T	3004 (approx)	China	Chinese standards include similar Al-Mn-Mg compositions under series 3xxx

There are no perfect one-to-one equivalents across all standards because impurity limits and testing protocols differ, but AA3004 and EN AW-3004 are essentially the same family name under US and European systems. JIS and GB/T classes map similarly but users should verify exact chemical limits and mechanical-property requirements in the applicable specification before substitution; trace-element tolerances and surface quality specifications can vary by region and producer.

Corrosion Resistance

EN AW-3004 exhibits generally good atmospheric corrosion resistance typical of 3xxx-series alloys, forming a stable oxide that protects the substrate under normal indoor and industrial exposures. It resists uniform corrosion well and performs adequately in mildly corrosive outdoor settings. Surface finish, temper, and residual stresses from forming or welding influence the practical corrosion performance, and appropriate surface treatments or coatings are often applied for aesthetic or long-term exposure reasons.

In marine or chloride-bearing environments, EN AW-3004 performs moderately well but is outperformed by 5xxx (Al-Mg) alloys specifically optimized for seawater resistance. Pitting can occur where chloride concentrations are high; therefore for long-term unprotected marine service, selection of 5xxx alloys or protective coatings is recommended. Stress corrosion cracking susceptibility is low compared with high-strength heat-treatable alloys, but localized corrosion and galvanic interactions can accelerate attack where dissimilar metals are coupled.

Galvanically, 3004 is anodic relative to stainless steels and copper alloys, and care must be taken in joint design and fastener selection to avoid accelerated corrosion. Typical practice is to isolate aluminum from more noble metals or to use compatible fasteners and protective barriers; in many architectural and packaging applications, its corrosion resistance and surface finish are adequate with standard anodizing or coating processes.

Fabrication Properties

Weldability

EN AW-3004 is readily welded by standard fusion processes such as TIG (GTAW) and MIG (GMAW) with appropriate joint preparation and filler selection. Recommended filler wires include Al-Si (e.g., ER4043) and Al-Mg (e.g., ER5356) types depending on desired corrosion resistance and mechanical properties of the weld; ER5356 provides higher strength but slightly reduced fluidity compared with ER4043. Because 3004 is non-heat-treatable, HAZ softening is not a heat-driven overaging issue, but cold-worked parent material will locally soften in the HAZ, reducing local hardness and strength; distortion control and post-weld mechanical operations should be planned accordingly. Hot-cracking tendency is low for Al-Mn-Mg alloys but can be exacerbated by poor fit-up, contaminants, or excessive restraint.

Machinability

Machinability of 3004 is moderate to poor relative to free-machining aluminum alloys; it machines better than high-strength aluminum alloys but is less ideal than specialized free-cutting grades. Typical machining uses carbide tooling with moderate cutting speeds and higher feed rates to avoid built-up edge; turning, drilling and milling must account for gummy chip formation under some feed/insert conditions. Coolant and chip evacuation strategies are important for maintaining surface finish and tool life, and pre-hardening (work-hardened tempers) will reduce machinability further compared to annealed material.

Formability

Formability is one of the strong points for EN AW-3004 in annealed conditions and in partially softened tempers; it supports deep drawing, ironing and complex stamping with relatively tight bend radii. Recommended minimum inside bend radii depend on thickness and temper but are typically in the range of 0.5–1.5× material thickness for O and H24 tempers, with larger radii needed for fully hard H18. Cold-worked tempers respond predictably to incremental bending but springback and anisotropy must be anticipated in tooling design; warm forming is occasionally used to extend formability for thicker gauges.

Heat Treatment Behavior

EN AW-3004 is a non-heat-treatable alloy; strength alterations are accomplished almost exclusively through cold work (strain hardening) and annealing operations. There is no beneficial solution-treatment and artificial-aging cycle that produces the dramatic strength increases seen in 6xxx or 7xxx series alloys. Annealing cycles for stress relief and restoration of ductility are typically performed at temperatures between ~300–415 °C with soak times determined by section thickness and desired recrystallization.

Work hardening is accomplished by cold rolling, drawing or bending and is the primary method of achieving H-tempers; stabilization or partial anneals (H2x/H24) are used to achieve intermediate property sets and to control residual stresses. For critical dimensional and mechanical-property control, manufacturers commonly specify temper designation and percent cold work rather than relying on thermal treatments.

High-Temperature Performance

At elevated service temperatures, EN AW-3004 experiences gradual loss of strength and modulus relative to room temperature values, with significant softening occurring above approximately 150–200 °C. Continuous exposure above these temperatures accelerates recovery and recrystallization processes that reduce work-hardened strength, so high-temperature structural service is limited. Oxidation is slow at typical service temperatures and does not produce rapid scaling, but long-term exposure in high-temperature oxidizing atmospheres will produce surface thickening typical of aluminum alloys.

Weld heat-affected zones show localized softening as cold-worked regions recrystallize under thermal exposure; design must account for reduced local strength and potential distortion. For intermittent elevated-temperature exposure (short cycles or thermal shocks), 3004 retains reasonable dimensional stability, but repeated cycling will accelerate microstructural changes and mechanical-property degradation.

Applications

Industry	Example Component	Why EN AW-3004 Is Used
Automotive	Trim panels, interior components	Good formability and moderate strength for stamped and formed parts
Packaging	Beverage can stock, lids	Combination of drawability, surface finish and increased strength over 3003
HVAC / Building	Ducting, cladding, soffits	Corrosion resistance and ease of roll-forming and seam joining
Appliances	Exterior panels, housings	Cost-effective aesthetics and manufacturability
Electronics	Heat spreaders, enclosures	Thermal conductivity combined with formability for thin sections

EN AW-3004 is widely used where sheet metal forming, corrosion resistance and a favorable surface finish are required without the need for the highest possible tensile strength. Its compatibility with common coatings and anodizing finishes also supports architectural and consumer-visible applications.

Selection Insights

Choose EN AW-3004 when you need better strength than commercially pure aluminum (1100) while retaining much of the formability and corrosion resistance that make Al attractive. Compared with 1100, 3004 trades some electrical conductivity and ultimate ductility for a meaningful increase in yield and tensile strength, making it a better choice for structural sheet and can stock.

Compared with nearby work-hardened alloys such as 3003 and 5052, EN AW-3004 sits between them: it offers higher strength than 3003 due to Mg additions and often better formability than higher-Mg 5052, while 5052 will outperform 3004 in aggressive marine chloride environments. When compared with heat-treatable alloys such as 6061 or 6063, 3004 is preferred for deep drawing and surface-critical sheet applications despite lower achievable peak strengths because it avoids heat-treatment distortion and maintains superior forming behavior in thin gauges.

For procurement and design, prioritize 3004 when manufacturing steps include extensive cold forming and when coatings or anodizing are planned; consider 5xxx or 6xxx alternatives only if seawater resistance or much higher static strength is required, respectively.

Closing Summary

EN AW-3004 remains a practical and broadly applicable alloy for rolled sheet and coil applications where a balance of formability, corrosion performance, surface quality and moderate strength is required. Its reliance on work-hardening rather than heat treatment simplifies processing for many forming-dominated supply chains and keeps it relevant for packaging, architectural and general sheet-metal industries.