Aluminum 3033: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

3033 is a member of the 3xxx series of aluminum alloys, which are manganese-bearing, non-heat-treatable, strain-hardenable alloys. It sits in the Mn-dominant family where manganese is the primary strength alloying addition and is processed primarily by cold working to develop strength.

Major alloying additions in 3033 typically include manganese with minor amounts of silicon, iron, copper, magnesium, zinc, chromium and titanium; these trace elements are tuned to balance strength, formability and corrosion resistance. The alloy relies on solid-solution strengthening from Mn and minor elements plus work-hardening (strain hardening) rather than precipitation hardening, so temper and cold-work history are the main levers for mechanical performance.

Key traits of 3033 include moderate strength relative to commercial-purity aluminum, good formability in annealed condition, reasonable corrosion resistance in many atmospheres, and generally good weldability with standard aluminum welding processes. Typical industries using 3033 include building and construction, automotive body and trim, HVAC, consumer goods, and some marine and electronics components where moderate strength and good formability are needed.

Engineers choose 3033 when a combination of enhanced strength over pure Al, excellent forming characteristics in the O temper, and economical processing is needed; it is selected over higher-strength heat-treatable alloys when deep drawing or complex forming is required or when post-weld strength retention matters more than maximum achievable yield.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed; easiest to form and to draw
H12	Low-Medium	Moderate	Very Good	Very Good	Light strain-hardened, some dimensional stability
H14	Medium	Moderate-Low	Good	Very Good	Common sheet temper; balance of formability and strength
H16	Medium	Moderate-Low	Good	Very Good	Stronger than H14 with reduced elongation
H18	Medium-High	Lower	Fair	Very Good	Heavier strain hardening for higher yield
H22	Medium	Moderate	Good	Very Good	Strain-hardened and partially annealed for form control
H24	Medium-High	Moderate-Low	Fair	Very Good	Strain-hardened and stabilized for springback control
H111	Variable	Variable	Variable	Very Good	Thermal/mechanical condition between O and H1x; mild work-hardening

Temper has a primary influence on mechanical properties because 3033 gains strength almost exclusively by plastic deformation and dislocation accumulation. Annealed O material is used for deep drawing and complex forming, while H1x tempers are used where higher yield and dimensional control are required.

Weldability remains generally high across tempers because 3033 is not precipitation hardenable; however, local softening in the heat-affected zone can reduce strength adjacent to welds in heavily cold-worked tempers. Selecting the proper temper is therefore a trade-off between formability, final part strength and expected post-fabrication processes.

Chemical Composition

Element	% Range	Notes
Si	0.10–0.60	Controls fluidity in casting and can modestly influence strength
Fe	0.20–0.70	Common impurity; impairs ductility if elevated
Mn	0.6–1.5	Principal strengthening element for 3xxx alloys
Mg	0.02–0.20	Minor contribution to strength and corrosion behavior
Cu	0.02–0.20	Small amounts increase strength but can reduce corrosion resistance
Zn	0.02–0.25	Minor influence on strength; excessive Zn reduces performance
Cr	0.01–0.10	Grain structure control and resistance to recrystallization
Ti	0.01–0.15	Grain refiner in cast or wrought products
Others (each)	0.05 max	Trace additions and residuals; total others controlled

All composition ranges above are typical industry ranges for 3033-type alloys and individual supplier specifications or standards may vary. Manganese is the dominant controlled element providing solid-solution strengthening and controlling grain structure, while the minor elements tune workability, surface quality and corrosion resistance.

Small additions of Mg and Cu can raise strength further but compromise some corrosion resistance; iron and silicon are tolerated as impurities but must be limited to avoid brittle intermetallics that harm formability and fatigue performance.

Mechanical Properties

As a non-heat-treatable alloy, 3033's tensile behavior is primarily a function of temper and thickness. In the annealed O condition 3033 exhibits relatively low yield and moderate ultimate tensile strength with high elongation ideal for drawing operations. In strain-hardened tempers (H14–H18), yield and tensile strength increase while elongation decreases; work-hardening exponent and r-value influence sheet forming and springback behavior.

Hardness correlates with temper and cold-work; annealed hardness is low and increases substantially with H1x processing. Fatigue performance is modest and highly dependent on surface finish, residual stresses from forming/welding, and the presence of corrosion; polished, cold-worked parts typically show better endurance limits than rough, annealed components. Thickness has the expected influence: thinner sheet often shows higher apparent strength after cold working due to increased cold-work per unit area, while heavy plate is less responsive to strain hardening and may be offered only in softer tempers.

Property	O/Annealed	Key Temper (e.g., H14/H18)	Notes
Tensile Strength	~110–150 MPa	~160–230 MPa	Wide range depending on cold work and thickness
Yield Strength	~35–80 MPa	~120–200 MPa	Yield rises substantially with H1x tempers
Elongation	~25–40%	~6–20%	Annealed has high ductility; H18 is much lower
Hardness (HRB)	~20–40	~40–75	Hardness correlates with strain hardening level

Values listed are typical indicative ranges for 3033 sheet and extruded forms; exact test data should be taken from supplier certifications for design calculations. Designers must consider reduced strength in the heat-affected zone after welding and when specifying forming operations, account for springback predicted from temper-specific yield and modulus behavior.

Physical Properties

Property	Value	Notes
Density	2.70 g/cm³	Typical for aluminum alloys; used in weight and stiffness calculations
Melting Range	~640–660 °C	Solidus–liquidus span influenced by alloying additions
Thermal Conductivity	~120–160 W/m·K	Lower than pure Al; good for non-critical heat dissipation
Electrical Conductivity	~30–45 % IACS	Reduced from pure aluminum by alloying; suitable for some conductive parts
Specific Heat	~896 J/kg·K	Approximate at ambient temperature
Thermal Expansion	~23–24 µm/m·K (20–100°C)	Typical isotropic expansion for wrought Al alloys

3033 retains the lightweight advantage of aluminum with density around 2.70 g/cm³, making it attractive where weight reduction is important. Thermal and electrical conductivities are lower than pure aluminum but adequate for many heat-spreading and moderate-conductivity applications; for high-performance heat-sink work, more conductive alloys or pure Al may be preferred.

Thermal expansion is similar to other Al alloys and should be accommodated in assemblies with dissimilar materials to avoid thermal-induced stresses or dimensional mismatch over service temperature cycles.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2–6.0 mm	Responds well to cold work	O, H14, H16, H18	Used for panels, HVAC, enclosures
Plate	>6.0 mm	Lower strain-hardening response	O, H111	Heavy sections typically supplied softer
Extrusion	Section dependent	Cold-working limited by profile	O, H112	Complex profiles for structural or decorative use
Tube	0.4–6.0 mm wall (varies)	Cold-drawn tubes gain strength	O, H14, H16	Used for furniture, HVAC, heat exchangers
Bar/Rod	Ø3–Ø60+ mm	Limited work-hardening after extrusion	O, H111	Machining stock, fasteners, shafts

Sheet and thin gauge products of 3033 are highly formable and the majority of structural and decorative applications use sheet in O or light H tempers. Extrusion and tube forms require careful control of quench and natural aging to manage dimensional stability, and heavier plate is generally sold in softer conditions because work-hardening of thick sections is less efficient.

Processing differences matter: sheet can be deep-drawn or roll-formed readily, while extrusions allow complex cross-sections but may require additional machining; weldability and subsequent finishing (anodizing, painting) guide product form choice for the end application.

Equivalent Grades

Standard	Grade	Region	Notes
AA	3033	USA	Industry designation for the alloy in the Aluminum Association registry
EN AW	3033	Europe	Common commercial designation under EN standards
JIS	—	Japan	No exact 1:1 JIS equivalent; closest behaviors align with Al-Mn 3xxx series alloys
GB/T	—	China	No single direct equivalent in many public GB listings; similar to 3A21/3xxx family

3033 is standardized under Aluminum Association and often identified as EN AW-3033 in Europe; however, some regions may not list a strict 1:1 counterpart in national standards. Where direct equivalents are not published, engineers should compare chemistry and temper behavior to nearby 3xxx series alloys (e.g., 3003, 3004) and validate performance via supplier data.

When substituting, confirm key metrics such as Mn content, impurity limits, tempering response, and supplier process controls to avoid unexpected differences in forming, corrosion resistance or weldability.

Corrosion Resistance

3033 exhibits good general atmospheric corrosion resistance typical of Al-Mn alloys; the naturally forming oxide provides protection in urban and rural environments. In industrial atmospheres with high SO2 or acidic pollutants, performance is reduced compared with more noble alloys or specially coated systems, so surface protection or appropriate coatings are commonly specified.

In marine or high-chloride environments, 3033 performs moderately well but is not as robust as 5xxx series (Al-Mg) alloys specifically formulated for seawater exposure. Pitting resistance is fair in mildly corrosive conditions; for prolonged immersion or splash-zone exposure, 5xxx series or proper protective coatings are recommended.

Stress corrosion cracking susceptibility is low for 3033 because it is non-heat-treatable and lacks precipitate-hardened microstructures that can promote cracking; however, residual tensile stresses from forming or welding combined with certain environments may still present localized risks. Galvanic interactions follow standard aluminum behavior: when coupled to more noble metals (copper, stainless steels in certain conditions), aluminum is anodic and will corrode preferentially unless electrically insulated or cathodic protection is used.

Fabrication Properties

Weldability

3033 welds readily using common aluminum processes such as TIG (GTAW) and MIG (GMAW). Recommended filler alloys are typically Al-Si (e.g., 4043) for improved fluidity and reduced cracking tendency, or Al-Mg fillers (e.g., 5356) when higher weld strength and better matching of base-metal ductility are required. Hot-cracking risk is low relative to some high-strength alloys, but careful joint design, cleanliness and control of heat input are important to minimize porosity and HAZ softening.

Machinability

Machinability of 3033 is moderate and similar to other 3xxx series alloys; it is more difficult than free-machining aluminum alloys but easier than many high-strength heat-treatable alloys. Carbide tooling with positive rake, rigid setup, and flood cooling produce consistent chips and tool life; recommended cutting speeds are moderate and feeds tuned to prevent built-up edge. Surface finish and dimensional accuracy are influenced by the temper; more highly strain-hardened tempers machine with slightly higher forces and reduced tendency to burr.

Formability

Formability is one of 3033's strengths in the annealed O condition, enabling deep drawing, stretch forming and complex bending with minimal cracking. Minimum recommended bend radii depend on temper and thickness but typical values are on the order of 1–3 times material thickness for moderate draws and larger for H18/H24 tempers. Cold-working increases strength but reduces elongation and increases springback, so designers must choose the temper that balances forming requirements and final mechanical properties.

Heat Treatment Behavior

3033 is a non-heat-treatable alloy, so traditional solution treatment and aging paths used for 2xxx/6xxx/7xxx alloys do not produce precipitation strengthening. Attempted artificial aging yields no significant increases in strength beyond small natural aging effects. For this reason, thermal processing is used chiefly to anneal or soften material rather than to harden it.

Work hardening is the primary strengthening mechanism: incremental increases in dislocation density via cold rolling, drawing or bending raise yield and tensile strengths. Full annealing (O temper) restores ductility by recrystallization and recovery. Stabilized tempers (H112, H22, H24) are achieved by combinations of cold work and low-temperature heat treatments intended to control springback and dimensional stability without relying on precipitation.

High-Temperature Performance

Operational strength of 3033 diminishes with increasing temperature; above roughly 100–150 °C, recovery and creep mechanisms accelerate and yield/tensile values drop noticeably. For continuous operation at elevated temperatures, designers should assume degraded mechanical properties and consider alloys specifically designed for higher-temperature retention.

Oxidation behavior is benign for aluminum — a protective oxide forms quickly — but prolonged exposure to high-temperature humid or chloride-containing atmospheres can invite corrosion acceleration. Welding zones and heavily cold-worked areas are particularly susceptible to localized softening or reduced creep resistance in thermal excursions.

Applications

Industry	Example Component	Why 3033 Is Used
Automotive	Interior trim, decorative panels	Good formability, reasonable strength, cost-effective
Marine	Non-structural housings, trim	Moderate corrosion resistance and light weight
Aerospace	Interior fittings and brackets	Favorable strength-to-weight for non-critical structural parts
Electronics	Chassis, moderate-duty heat spreaders	Balance of formability and thermal conductivity

3033 is commonly chosen for parts requiring complex forming, reliable corrosion performance in non-critical marine exposure, and economical production in sheet-form parts. Its combination of good weldability, light weight and predictable work-hardening behavior makes it useful for a broad range of mid-duty structural and cosmetic components.

In many applications 3033 provides a pragmatic balance between cost and performance when the absolute highest strength is not mandatory but formability and post-fabrication integrity are essential.

Selection Insights

Choose 3033 when you need better strength than commercially pure aluminum while retaining excellent formability and easy welding; it is a practical middle ground in the 3xxx family. For deep-drawn parts where subsequent strengthening via cold work is planned, 3033 in O temper allows maximum formability and predictable hardening.

Compared with commercially pure aluminum (e.g., 1100), 3033 trades some electrical and thermal conductivity for improved strength and better resistance to denting and fatigue. Compared with common work-hardened alloys (e.g., 3003 or 5052), 3033 typically sits near the top of the Mn-based family for a balance of strength and corrosion resistance — it is often a step up from 3003 in strength while retaining similar forming behavior. Compared with heat-treatable alloys (e.g., 6061 or 6063), 3033 will not reach the same peak strength but is preferred where deep forming, welding without aging concerns, or lower-cost sheet availability is more important than maximum static strength.

Closing Summary

3033 remains relevant where engineers require a manufacturable, weldable and moderately strong aluminum solution that balances formability, corrosion resistance and cost; its predictable work-hardening response and broad availability in sheet and extrusion forms make it a durable choice for many industrial and consumer applications.