Aluminum 3007: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

3007 is a member of the 3xxx series aluminum alloys, a family defined by manganese as the primary alloying element. This series is non-heat-treatable and derives its strength predominantly through solid solution effects and work hardening rather than precipitation hardening.

Major alloying elements in 3007 typically include manganese with small controlled additions of silicon, iron and trace magnesium or chromium to tune strength, recrystallization behavior and corrosion performance. The overall strengthening mechanism is cold work (strain hardening) combined with microstructural control from alloying; ageing and solution treatments play negligible roles in peak-strength development.

Key traits of 3007 are moderate-to-high formability in the annealed condition, good corrosion resistance in atmospheric environments, reasonable weldability by common fusion processes, and a strength level above commercially pure aluminum but below typical heat-treatable 6xxx or 7xxx series alloys. These attributes make 3007 attractive in industries where fabrication flexibility and corrosion performance are important, such as automotive inner panels, architectural cladding, building façades, and consumer appliance components.

Designers choose 3007 over other alloys when a balance of formability, surface quality and modest strength is required, or when post-form processing (deep drawing, bending) is a priority. It is selected instead of highly alloyed or heat-treatable materials when cost, ease of forming and resistance to atmospheric corrosion are more critical than maximum yield strength.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (20–40%)	Excellent	Excellent	Fully annealed condition for maximum ductility
H12	Low-Medium	Moderate (10–25%)	Very Good	Very Good	Partial hardening with good drawability
H14	Medium	Moderate-Low (6–15%)	Good	Good	Typical commercial cold-worked temper for moderate strength
H16	Medium-High	Low (4–10%)	Fair	Good	Higher strain hardening for stiffer components
H18	High	Low (≤5%)	Limited	Good	Highest cold-worked temper used for higher yield needs
T4*	N/A/Not typical	N/A	N/A	N/A	Listed for completeness — 3xxx alloys are not typically precipitation hardened

Temper selection for 3007 strongly affects the strength-ductility trade-off: increasing H-number increases yield and tensile strength at the expense of elongation and formability. For forming-intensive operations, O or low H-tempers are preferred; for finished parts needing higher stiffness or springback control, H16/H18 may be specified.

Chemical Composition

Element	% Range	Notes
Si	0.05–0.50	Controlled to limit casting-related inclusions and retain surface finish.
Fe	0.20–0.70	Typical impurity; higher Fe reduces ductility and surface quality.
Mn	0.6–1.5	Principal strengthening alloying element in the 3xxx family.
Mg	0.05–0.50	Minor additions improve strain hardening and strength slightly.
Cu	≤0.20	Kept low to limit corrosion susceptibility and maintain weldability.
Zn	≤0.25	Low levels to avoid deleterious effects on corrosion and embrittlement.
Cr	≤0.10	Small amounts can control recrystallization and grain structure.
Ti	≤0.10	Grain refiner in cast or heavily worked products in trace amounts.
Others (each)	≤0.05	Trace elements kept low; Aluminium remainder balance

The composition shown is representative of typical industrial 3007 chemistry rather than a single formal standard. Manganese is the primary microalloying element giving most of the as-worked strength. Silicon and iron control castability and inclusions; small magnesium additions enhance strain-hardening response and modestly raise strength, while low copper and zinc preserve corrosion resistance and weldability.

Mechanical Properties

In tensile behavior, 3007 shows a ductile, work-hardenable response with a relatively flat strain-hardening exponent in the annealed condition and increasing yield with cold work. Annealed specimens typically exhibit high total elongation and low yield strength, while cold-worked tempers show higher yield and tensile values but reduced ductility and toughness. Fatigue behavior is controlled by surface quality, cold-work level and thickness; polished, cold-worked surfaces can show improved fatigue limits versus rough-rolled conditions.

Yield strength scales with cold reduction and can be increased predictably with H-tempers, but the alloy lacks a precipitation hardening path to reach the high yields of 6xxx or 7xxx alloys. Hardness correlates with tensile strength and cold reduction; thin gauge sheets work-harden faster and therefore often reach higher strength for the same temper than thicker plates.

Property	O/Annealed	Key Temper (H14)	Notes
Tensile Strength (MPa)	100–140	170–220	Values depend on thickness and cold work; values are typical ranges.
Yield Strength (0.2% Proof, MPa)	30–60	110–160	H14 significantly raises yield via strain hardening.
Elongation (%)	20–40	6–15	Annealed material suitable for deep drawing; H-tempers limit forming.
Hardness (HB)	25–45	55–85	Brinell ranges approximate; hardness increases roughly linearly with cold work.

Thickness affects mechanical response: thin gages cold work more uniformly and can achieve higher strengths in H-tempers, while thicker sections may retain lower yield and higher toughness. Pay attention to anisotropy introduced by rolling and to test directionality for critical structural applications.

Physical Properties

Property	Value	Notes
Density	2.70 g/cm³	Typical for commercial aluminum alloys; useful for mass calculations.
Melting Range	640–660 °C	Narrow solidus-liquidus window typical of wrought alloys.
Thermal Conductivity	150–180 W/(m·K)	Lower than pure Al due to alloying; still good for heat-spreading.
Electrical Conductivity	30–45 %IACS	Alloying reduces conductivity compared with pure aluminum.
Specific Heat	880–910 J/(kg·K)	Approximately 0.88–0.91 J/g·K at room temperature.
Thermal Expansion	23–24 µm/(m·K)	Similar to other Al-Mn alloys; important for thermal mismatch calculations.

The physical properties make 3007 suitable for components that require good thermal conduction but cannot afford the cost or reduced formability of higher-alloyed heat-treatable materials. Electrical and thermal conductivity remain adequate for many heat-sink and enclosure applications, while density advantages drive weight-sensitive designs in transport and architecture.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2–6.0 mm	Work hardening increases with reduction; thin sheets gain strength faster	O, H12, H14	Widely used for panels, deep drawing and stamping
Plate	6–50 mm	Lower strain-hardening per pass; thicker sections show lower cold-worked strength	O, H18	Used where thicker sections are needed with modest forming
Extrusion	Profiles up to 300 mm	Strength depends on extrusion ratio and subsequent cold work	O, H12	Extrusions used for architectural profiles and framing
Tube	0.5–10 mm wall	Cold drawing produces predictable increases in yield	O, H14	Tubing for HVAC, architectural, and structural elements
Bar/Rod	3–75 mm dia.	Work hardening through drawing and cold finishing	O, H16	Used for small machined components or structural rods

Sheet and strip manufacture dominates for 3007, where rolling and annealing cycles are tuned for surface finish and drawability. Extrusion and tube production require careful control of billet chemistry and homogenization to avoid surface defects and to control recrystallization behavior. Plate production is less common and used when thicker cross-sections with good corrosion resistance are needed.

Equivalent Grades

Standard	Grade	Region	Notes
AA	3007	USA	Primary designation used in some vendor catalogs; nomenclature follows 3xxx series.
EN AW	3007	Europe	Commercial alloy designation used in some European supply chains; check supplier specs.
JIS	A3007 (informal)	Japan	No universal JIS direct equivalent in some cases; check national standards.
GB/T	3007	China	Chinese suppliers may use the same numeric designation but verify composition tolerances.

Equivalency between regions is often approximate because different standards permit slightly different compositional tolerances and property verification methods. When substituting grades across standards, confirm chemistry limits, mechanical test conditions and temper designations since small variations in Mn or Mg can affect formability and recrystallization.

Corrosion Resistance

3007 exhibits good general atmospheric corrosion resistance due to its relatively low copper and zinc content and the protective aluminum oxide film. In industrial and mildly polluted environments it performs well long-term, with pitting largely controlled by surface finish and the presence of aggressive halides.

In marine or chloride-rich environments, 3xxx alloys, including 3007, show reasonable resistance but are generally outperformed by 5xxx magnesium-bearing alloys which combine higher corrosion resistance and strength in seawater. Surface treatments, anodizing or organic coatings are commonly applied to extend life in marine exposure.

Stress corrosion cracking susceptibility is low compared with high-strength heat-treatable alloys; however, concentrated chloride environments and tensile residual stresses can raise the risk. Galvanic interactions should be considered: when electrically coupled to more noble metals such as stainless steel or copper, aluminum will be the anodic partner and corrode preferentially unless insulated or isolated.

Compared with 1xxx series (commercially pure) alloys, 3007 sacrifices some electrical and thermal conductivity for improved strength and creep resistance. Compared to 5xxx alloys, it trades some corrosion resistance in aggressive seawater for superior formability and often lower cost.

Fabrication Properties

Weldability

3007 is readily welded with common fusion processes such as MIG (GMAW) and TIG (GTAW) with low risk of hot cracking when good practice is used. Recommended filler alloys are low-alloyed aluminum fillers compatible with the 3xxx family; ER4043 (Al-Si) and ER5356 (Al-Mg) are often used depending on joint requirements and post-weld corrosion considerations. Heat-affected zone softening is modest due to the non-heat-treatable nature, but weld area mechanical properties depend on joint design and residual stress control.

Machinability

Machinability of 3007 is moderate and similar to other 3xxx series alloys; it machines better than some highly alloyed or age-hardenable alloys due to ductile chip formation. Carbide tooling with positive rake and good coolant flow improves surface finish and tool life; speeds are typically conservative compared with steels and depend on temper and section thickness. Chips tend to be continuous and stringy in soft tempers, so chip control strategies (segmented cutting, chip breakers) are useful for automated operations.

Formability

Formability is a primary strength of 3007, particularly in the annealed O temper where deep drawing, spinning and complex stamping are feasible with low springback. Bend radii as low as 1–2× thickness are possible in O temper for many geometries; H-tempers increase springback and require larger radii or force. Cold work improves yield and can enable forming-stiffness trade-offs, but multiple-stage forming with intermediate anneals is common for intricate shapes.

Heat Treatment Behavior

As a non-heat-treatable alloy, 3007 does not respond to solution heat treatment and artificial aging in the same way as 6xxx or 7xxx alloys. Attempts at solution treatment and quench-aging produce only minor changes because manganese and the other principal elements do not precipitate strengthening phases under conventional treatments.

The principal way to modify strength is cold working (H-tempers) and controlled annealing. Full anneal (O) is achieved by heating to a temperature sufficient to recrystallize the structure (typically in the range used for 3xxx alloys), followed by slow cool to produce maximum softness and formability. Partial anneals and tempering via controlled strain and thermal cycles are used to tailor drawability or tensile properties for specific forming sequences.

For applications requiring recovery of ductility after significant cold work, standard annealing cycles are effective at restoring formability without complex heat treatment equipment. Always verify mechanical properties after any thermal treatment since microstructural coarsening or surface oxidation can alter performance.

High-Temperature Performance

3007 maintains usable mechanical properties up to moderate temperatures but experiences significant strength loss above approximately 150–200 °C. Long-term exposure at elevated temperatures accelerates recovery and recrystallization, reducing the work-hardened contributions to yield strength and stiffness.

Oxidation at service temperatures is typical of aluminum – a protective oxide forms rapidly and limits further attack, but scale and surface changes may affect brazing or coating adhesion. Heat exposure near melting range is not relevant for wrought product service, but thermal cycles during fabrication (e.g., welding) can locally change hardness and ductility in the HAZ.

For elevated-temperature structural applications, consider alloys specifically rated for high-temperature retention; 3007 is best used below the temperature range where significant softening occurs or where thermal cycling is minimal.

Applications

Industry	Example Component	Why 3007 Is Used
Automotive	Inner body panels, reinforcement strips	Excellent formability for deep drawing and stamping with adequate strength
Marine	Architectural marine structures, inland craft fittings	Good atmospheric corrosion resistance and ease of fabrication
Aerospace (non-primary)	Interior fittings, fairings	Favorable strength-to-weight and surface finish for non-structural parts
Electronics	Heat spreaders, enclosures	Good thermal conductivity and corrosion resistance for housings
Building & Architecture	Cladding, soffits, façades	Formability, surface finish and corrosion resistance for visible surfaces

3007 finds a niche where complex forming, good corrosion resistance and cost-effectiveness are required together. It is widely used for decorative or non-critical structural parts where manufacturability and long-term environmental durability matter.

Selection Insights

When choosing 3007, prioritize applications that require high formability and good atmospheric corrosion resistance but do not demand the peak strength of heat-treatable alloys. It is cost-effective and easier to form than many higher-strength alloys, and it welds and finishes well.

Compared with commercially pure aluminum (1100), 3007 sacrifices some electrical and thermal conductivity and slightly higher ductility for considerably improved strength and better mechanical stability after forming. Compared with common work-hardened alloys such as 3003 or 5052, 3007 typically sits between them: it provides higher strength than very soft 1xxx/3xxx alloys while retaining better formability and sometimes better corrosion resistance than Mg-rich 5xxx grades. Compared with heat-treatable alloys like 6061 or 6063, 3007 offers superior drawability and often lower cost; choose 3007 when complex forming and surface finish are more critical than the highest achievable peak strength.

Use 3007 when part geometry, forming steps and surface requirements dominate the design constraints; consider alternatives when maximum structural capacity or seawater-exposed load-bearing performance is required.

Closing Summary

3007 remains relevant as a practical 3xxx-series alloy that balances formability, corrosion resistance and moderate strength for a wide range of fabricated components. Its combination of ease of fabrication, predictable work-hardening behavior and favorable surface characteristics make it a dependable choice where manufacturability and environmental durability are primary design drivers.