Aluminum 1200: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

Alloy 1200 is part of the 1xxx series of aluminum alloys, classified as commercially pure aluminum with a minimum aluminum content of approximately 99.0%. The 1xxx series is characterized by very low intentional alloying and by property sets dominated by the base metal, not by strengthening additions. Typical minor alloying elements present in 1200 are iron and silicon as impurities, along with trace amounts of copper, manganese, magnesium, zinc and titanium that are controlled to tight limits.

1200 is a non-heat-treatable alloy whose mechanical strength is developed almost entirely through strain (work) hardening and by controlling temper. The alloy provides excellent electrical and thermal conductivity, outstanding corrosion resistance in many environments, superb formability and very good weldability. Its primary limitations are low absolute strength and reduced fatigue strength compared with intentionally alloyed systems.

Industries that commonly use 1200 include electrical conductors and busbars, heat exchangers and thermal management, chemical and food processing equipment, architectural and decorative elements, and thin-gauge foils for packaging. Engineers select 1200 when high conductivity, maximum corrosion resistance and extensive forming are higher priorities than peak strength, or when chemical purity is required for compatibility with process media.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High	Excellent	Excellent	Fully annealed condition, maximum ductility
H12	Low–Moderate	High	Very Good	Excellent	Partial work-hardening, retains good forming
H14	Moderate	Moderate	Good	Excellent	Typical commercially supplied cold-work temper
H16	Moderate–High	Moderate	Fair–Good	Excellent	Greater cold work for higher strength
H18	High	Low	Limited	Excellent	Heavily cold-worked for max non-heat-treated strength
H22 / H24	Moderate	Moderate	Good	Excellent	Strain-hardened + stabilized to maintain properties
H111	Low–Moderate	High	Very Good	Excellent	Slightly or unevenly strain-hardened condition

Temper directly controls the balance between strength and ductility because 1200 cannot be precipitation hardened. Heavily cold-worked tempers (H16, H18) raise yield and tensile strength at the cost of elongation and formability. Annealed (O) material provides the best drawability and ductility for deep forming and spinning operations.

Chemical Composition

Element	% Range	Notes
Al	Balance (~99.00 min)	Primary constituent; defines conductivity and corrosion resistance
Si	≤ 0.30	Impurity; minor influence on strength and casting behavior
Fe	≤ 0.30	Common impurity; can form intermetallics that affect ductility and electrical conductivity
Mn	≤ 0.03	Typically trace; minor effect on strength
Mg	≤ 0.03	Trace only; not deliberate strengthening agent in 1200
Cu	≤ 0.05	Kept very low to preserve corrosion resistance and conductivity
Zn	≤ 0.03	Trace; higher levels would reduce corrosion performance
Ti	≤ 0.03	Added occasionally as grain refiner in processing; usually very low
Others (each)	≤ 0.05	Sum of other elements kept low to maintain purity

The composition emphasizes aluminum purity to maximize thermal and electrical conductivity and to ensure excellent corrosion resistance. Small concentrations of iron and silicon appear as unavoidable impurities from smelting and recycling; they can form fine intermetallic particles that slightly affect mechanical properties and formability. Control of copper and zinc is important because even small increases in these elements reduce corrosion resistance and conductivity.

Mechanical Properties

In the annealed (O) condition, 1200 exhibits low tensile and yield strength but very high elongation and toughness, making it favorable for deep drawing and forming operations. Typical tensile strength in O condition is modest and varies with gauge and processing history; specialty sheet and foil can show different baselines. Fatigue resistance in annealed 1200 is limited by low static strength but benefits from good ductility and the absence of large second‑phase particles.

Cold working produces significant increases in both yield and tensile strength at the expense of elongation and formability. Because the alloy is essentially pure aluminum, the increase in tensile strength with work hardening is predictable and useful for tailoring part performance without heat treatment. Hardness correlates closely with temper and cold work; annealed material measures low on Brinell or Vickers scales while H‑tempers show proportionately higher readings.

Thickness and processing history influence mechanical behavior: thinner gauges typically exhibit higher apparent strength due to processing strains and work hardening during rolling. Surface condition, residual stresses from forming and the presence of intermetallic particles from impurities also modulate fatigue initiation and propagation in service.

Property	O/Annealed	Key Temper (H14)	Notes
Tensile Strength	~70–120 MPa	~120–160 MPa	Wide ranges reflect thickness and processing; H14 is a common commercial temper
Yield Strength	~20–50 MPa	~50–110 MPa	Yield increases markedly with strain hardening
Elongation	~30–45%	~10–30%	Elongation decreases as temper increases
Hardness (HB)	~13–25 HB	~25–45 HB	Hardness rises with cold work; reported values depend on measurement method

Physical Properties

Property	Value	Notes
Density	2.71 g/cm³	Typical for commercially pure aluminum alloys
Melting Range	~ 660 °C	Aluminum solidus/liquidus near 660 °C
Thermal Conductivity	~220–235 W/m·K (at 25 °C)	Very high conductivity; dependent on purity and temper
Electrical Conductivity	~58–62 % IACS	One of the highest among commercial Al alloys
Specific Heat	~0.897 J/g·K	Typical aluminum specific heat near ambient
Thermal Expansion	~23–24 ×10^-6 /K (20–100 °C)	Moderate coefficient; relevant for thermal cycling design

The physical property set of 1200—especially thermal and electrical conductivity—drives its selection for heat-sink, busbar and conductor applications. High conductivity is a direct consequence of the alloy’s high Al content and low impurity levels. Density and thermal expansion are similar to other aluminum alloys, so weight and thermal movement considerations follow standard aluminum design practices.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.2 mm – 6 mm	Work-hardened or annealed	O, H12, H14, H16	Widely used for enclosures, fins, cladding
Plate	>6 mm (limited)	Lower common for heavy sections	O, H111	1200 is rarely used for heavy plate due to low strength
Extrusion	Sectional profiles up to ~150 mm	Strength depends on post‑extrusion cold work	O, H112, H22	Extrusion used for busbars and custom profiles where purity matters
Tube	Thin- and mid-wall tubes	Behavior like sheet; work-hardening possible	O, H14	Used in heat exchangers and fluid handling
Bar/Rod	Diameters from a few mm up	Cold-drawn increases strength	O, H14, H18	Common for conductor rod and forming stock

Forming method, thickness and desired end-use dictate which product form and temper are chosen. Foil and thin sheet exploit the alloy’s ductility and conductivity in thermal and packaging applications. Extrusions and bars are used where cross-sectional purity or conductivity is required; in those forms, post‑extrusion cold work is commonly used to impart desired mechanical performance.

Equivalent Grades

Standard	Grade	Region	Notes
AA	1200	USA	ASTM/AA designation for commercially pure Al (~99.0% Al)
EN AW	1200 / Al99.0	Europe	EN designation aligns chemically with AA1200; used in European supply chains
JIS	A1080 / A1050 (closest)	Japan	JIS series has closely related commercially pure grades; exact impurity limits may differ
GB/T	1200 (Al99.0)	China	Chinese standard lists Al99.0 grade comparable to AA1200

Cross-referencing between standards is approximate because different national standards define slightly different impurity limits and allowable minor elements. In practice, AA1200, EN AW‑1200 and GB/T 1200 refer to commercially pure Al grades with similar performance, while JIS uses nearby designations (e.g., A1050/A1080) for very high‑purity aluminum. Buyers should compare standard certificates for exact composition and mechanical test requirements before specifying across regions.

Corrosion Resistance

1200 exhibits excellent general atmospheric corrosion resistance because of its high aluminum content and the formation of a stable, protective aluminum oxide film. In polluted industrial atmospheres and many rural environments it remains very durable, and localized pitting is uncommon compared with higher‑alloyed aluminum where second phases can act as initiation sites. The purity of 1200 reduces galvanic coupling within the material and minimizes preferential attack under many conditions.

In marine and chloride‑exposed environments, 1200 performs well for many service conditions but is still susceptible to localized pitting in stagnant saltwater with high chloride concentrations. Compared with 5xxx (Mg-bearing) alloys, 1200 shows superior resistance to certain corrosion modes due to absence of Mg‑containing phases, although 5xxx alloys can offer higher mechanical strength. Stress corrosion cracking is not a major concern for 1200 because it is non-heat-treatable and lacks precipitate structures that contribute to SCC susceptibility in some higher‑strength aluminum alloys.

Galvanic interactions must still be considered: 1200 is anodic relative to many common metals (stainless steel, copper products) and will corrode preferentially if electrically connected in a conductive electrolyte. Appropriate isolation, coatings or sacrificial design should be used when joining to dissimilar metals. Overall, 1200’s corrosion profile is among the most benign of structural aluminum alloys, which is why it is widely used in chemical processing and food‑handling equipment.

Fabrication Properties

Weldability

1200 welds readily by common fusion techniques such as TIG and MIG, with minimal hot‑cracking risk because the alloy is essentially single‑phase aluminum. Because of its high purity and low alloy content, filler additions are chosen to match conductivity and ductility requirements; common fillers include 1100 and 4043 when some filler alloying is acceptable. Heat‑affected zones do not experience deleterious precipitate dissolutions, but HAZ softening is not a design concern because 1200 is not strengthened by heat treatment.

Machinability

Machinability of 1200 is generally rated as fair to moderate because the alloy is soft and gummy compared with leaded brasses or free‑machining steels. Tooling should use sharp carbide or high‑quality HSS inserts with positive rake to produce continuous chips, and cutting speeds should be moderate to avoid work hardening at the tool interface. Chip control and coolant selection are important for surface finish; because the alloy is ductile, built‑up edge on tooling can be a dominant factor influencing surface integrity.

Formability

Formability is one of 1200’s strongest attributes, particularly in O and light H tempers. Deep drawing, spinning, bending and stretch forming are straightforward with small bend radii and excellent springback predictability. As temper is increased through cold work, bend radii and required forming forces change predictably; designers typically specify annealed material where severe forming is anticipated and use H tempers for parts where some strength is required after forming.

Heat Treatment Behavior

1200 is a non-heat-treatable alloy and therefore does not respond to solution treatment and precipitation hardening strategies used for 2xxx–7xxx series alloys. Attempts at artificial aging do not produce significant strengthening because there are no substantial alloying elements to form strengthening precipitates.

Strength adjustment in 1200 is achieved entirely through mechanical processes: cold rolling, drawing, stretching and controlled annealing. Annealing (O temper) is typically performed by heating to temperatures where recrystallization occurs to restore ductility; subsequent controlled cold work and stabilization produce the H‑tempers used commercially.

High-Temperature Performance

Service temperature limits for 1200 are governed by the rapid decline in strength above ambient temperatures and by accelerated microstructural changes at elevated temperatures. Mechanical properties begin to degrade measurably above approximately 100–150 °C, and designers generally avoid continuous structural use much above 150 °C where significant softening and creep can occur. For thermal management applications (heat sinks), 1200 remains functionally useful at elevated temperatures because conductivity remains high and the oxide layer provides oxidation resistance.

Oxidation behavior is benign: a thin, adherent Al2O3 film forms rapidly and protects the metal from further corrosion in air. In cyclic thermal environments, differential expansion and oxide spallation must be considered for joint design, but bulk oxidation is not typically a limiting factor for 1200 in normal industrial temperature ranges. Welded joints show no precipitation‑related embrittlement, but designers must account for reduction in mechanical margins at elevated service temperatures.

Applications

Industry	Example Component	Why 1200 Is Used
Electrical	Busbars, conductors, transformer components	High electrical conductivity and good formability
Marine / Chemical	Tanks, ducting, heat exchangers, process equipment	Excellent corrosion resistance and chemical compatibility
Thermal Management	Heat sinks, fins, evaporator coils	High thermal conductivity and ease of fabrication
Packaging / Consumer	Foil, decorative trim, food processing components	Purity, formability and surface finish
Architectural	Cladding, flashing, trim	Formability, corrosion resistance and aesthetics

1200’s combination of electrical/thermal conductivity, corrosion resistance and formability makes it a staple where purity and ease of fabrication outweigh the need for high structural strength. Its use spans from thin foils for packaging to formed components in corrosive environments and extruded profiles for electrical applications.

Selection Insights

Choose 1200 when conductivity, corrosion resistance and extreme formability are primary design drivers and when peak strength is not required. Its low cost and broad availability for sheet, foil and extruded forms make it an economical choice for many thermal, electrical and chemical processing applications.

Compared with commercially pure 1100, 1200 typically trades slightly higher allowable impurity content for similar conductivity and slightly higher cost efficiency; both are in the same commercial‑purity family. Compared with work‑hardened alloys like 3003 or 5052, 1200 offers superior electrical and thermal conductivity and often better pure‑aluminum corrosion behavior, but it provides lower strength; choose 1200 where conductivity and formability are more important than load‑carrying capacity. Compared with heat‑treatable alloys such as 6061 or 6063, 1200 is selected when welding, corrosion resistance and conductivity are more critical than achieving high peak strength through aging; 1200 is preferred for conductive or chemically sensitive components despite lower mechanical limits.

Closing Summary

Aluminum 1200 remains a highly relevant engineering material because it delivers a unique blend of high conductivity, outstanding corrosion resistance and superior formability at low cost. For applications where purity and fabricability dominate the design trade space, 1200 is often the most practical and efficient choice.