Aluminum 1095: Composition, Properties, Temper Guide & Applications

Comprehensive Overview

1095 is an aluminum alloy in the 1xxx series, representing a near-commercial-purity grade with minimum aluminium content approaching 99.95%. The 1xxx series is characterized by minimal intentional alloying; the designator 1095 signals very low levels of impurity elements and a focus on intrinsic aluminium properties rather than alloyed strengthening.

Major alloying elements are essentially impurities and residuals: silicon, iron and trace elements such as copper, manganese, magnesium, chromium and titanium at sub‑percent levels. Strength is obtained through strain hardening (work hardening) rather than precipitation heat treatment, since 1095 is not heat-treatable in the metallurgical sense.

Key traits include excellent electrical and thermal conductivity, high ductility and formability in annealed condition, and very good atmospheric corrosion resistance driven by its high purity. Weldability is generally excellent with standard fusion methods, but mechanical strength in the heat‑affected zone (HAZ) can be reduced after welding due to annealing effects.

Typical industries for 1095 include chemical processing, electrical conductors, heat exchange and cladding, bullion and foil production, and specialized architectural and decorative applications. Engineers choose 1095 when high conductivity, superior formability, or maximal corrosion resistance from a near‑pure aluminium is required over higher‑strength but lower‑conductivity alloys.

Temper Variants

Temper	Strength Level	Elongation	Formability	Weldability	Notes
O	Low	High (30–45%)	Excellent	Excellent	Fully annealed, best ductility and conductivity
H12	Low–Medium	Moderate (15–30%)	Good	Excellent	Light strain hardening, still very formable
H14	Medium	Lower (8–20%)	Good	Excellent	Half‑hard; common for drawing and light stamping
H16	Medium–High	Low–Medium (6–12%)	Fair	Excellent	Quarter‑hard conditions for stronger formed parts
H18	High	Low (4–8%)	Limited	Excellent	Full‑hard cold worked, highest strength by cold work

Tempering for 1095 is achieved exclusively by controlled plastic deformation (H‑tempers) and by annealing (O). T‑tempers and precipitation treatments are not applicable because 1095 lacks significant solute elements needed for age hardening. The selected temper is a primary design variable: annealed O gives maximum forming latitude and conductivity, while progressively higher H‑tempers trade formability for strength through dislocation density increase.

Chemical Composition

Element	% Range	Notes
Si	≤0.25	Typical impurity; influences castability and small effect on strength
Fe	≤0.95	Primary residual; higher Fe can form intermetallics that reduce ductility
Mn	≤0.05	Usually minimal; can slightly influence grain structure if present
Mg	≤0.05	Minimal; not sufficient for precipitation strengthening
Cu	≤0.05	Kept very low to preserve corrosion resistance and conductivity
Zn	≤0.05	Trace levels only; little strengthening effect
Cr	≤0.01	Trace; controls grain growth in some processes
Ti	≤0.03	Grain refiner in cast or wrought processing when intentionally added
Others	Balance to 100% (Al ~99.90–99.99)	Remainder predominantly Al; "others" capture trace elements

The chemical makeup of 1095 emphasizes aluminium bulk with only trace residuals. Silicon and iron are the most consequential impurities; they form intermetallic particles that can act as sites for crack initiation and influence formability. Low copper and magnesium content preserve corrosion resistance and electrical conductivity, and intentional additions of minor grain refiners (Ti) are sometimes specified for controlled grain structure during casting or extrusion.

Mechanical Properties

Tensile behavior in 1095 is dominated by its purity and the degree of cold work. In annealed condition the alloy exhibits low yield and tensile strengths with long uniform elongation and high total elongation, producing very ductile behavior. Cold work (H‑tempers) increases yield and ultimate strengths primarily by dislocation accumulation and work hardening but reduces uniform and total elongation proportionally.

Hardness correlates closely with temper; Brinell and Vickers values are low compared with alloyed series and rise with H‑tempers. Fatigue performance benefits from the absence of coarse strengthening precipitates, but surface condition, impurity particle distribution and cold‑working state strongly influence initiation behavior. Thickness affects drawing and forming behavior: thin gauges are readily cold drawn in O condition, while thicker sections require more significant deformation energy and exhibit lower formability in hardened conditions.

Control of processing history (rolling reduction, anneal cycles, surface finish) is critical to achieve required toughness and fatigue life for structural components. Welding introduces local softening through recovery and recrystallization, affecting yield distribution across joints and potentially reducing fatigue resistance if not properly managed.

Property	O/Annealed	Key Temper (e.g., H14)	Notes
Tensile Strength	Typical 60–110 MPa	Typical 110–170 MPa	Wide range due to purity and work hardening; values are process dependent
Yield Strength	Typical 25–60 MPa	Typical 95–140 MPa	Yield increases markedly with H‑tempers from cold work
Elongation	Typical 30–45%	Typical 8–20%	Ductility falls as hardness and strength rise with temper
Hardness	Typical 15–30 HB	Typical 30–60 HB	Hardness roughly proportional to cold work; low absolute values vs alloyed series

Physical Properties

Property	Value	Notes
Density	2.70 g/cm³	Typical for aluminium; useful for mass and stiffness calculations
Melting Range	660–665 °C	Primary melting point of aluminium; narrow range due to high purity
Thermal Conductivity	~220–235 W/m·K (25 °C)	High conductivity close to pure aluminium; beneficial for heat sinks
Electrical Conductivity	~58–62 %IACS	Excellent electrical conductor; beneficial for busbars and conductors
Specific Heat	~900 J/kg·K (0–100 °C)	High specific heat compared with many metals; influences thermal inertia
Thermal Expansion	~23–24 µm/m·K	Typical coefficient for aluminium; important for thermal match design

The physical properties make 1095 attractive where heat and electrical conduction are priorities alongside low mass. Density and thermal expansion dictate design tolerances in assemblies with dissimilar materials. Melting and thermal conductivity inform processes such as brazing, welding and thermal management design, where the alloy’s high conductivity must be accommodated in heat input calculations.

Product Forms

Form	Typical Thickness/Size	Strength Behavior	Common Tempers	Notes
Sheet	0.1–6 mm	Uniform; thickness influences drawability	O, H12, H14	Widely used for cladding, heat exchangers, and decorative panels
Plate	>6 mm up to 50+ mm	Lower through‑thickness ductility in thick plate	O, H18	Less common; used when large, pure aluminium sections required
Extrusion	Complex profiles, wide range	Strength influenced by extrusion ratio and post‑work	O, H12, H14	Used for electrical busbars, architectural profiles, frame components
Tube	Thin to thick walled	Drawing and pilgering affect residual stresses	O, H14	Common for conduits and fluid handling where corrosion resistance matters
Bar/Rod	Diameters from 1 mm to 200 mm	Cold drawing increases strength	O, H16, H18	Used for fabricated parts, rivets, and specialty electrical conductors

Processing differences are significant between wrought sheet/plate and extrusion or tube products. Rolling and cold drawing introduce controlled work hardening and texture that influence anisotropy, formability and mechanical response. Choice of product form should align with joining strategy and final temper requirements because subsequent forming or welding can alter local mechanical and electrical performance.

Equivalent Grades

Standard	Grade	Region	Notes
AA	1095	USA	American Aluminium Association designation for near‑pure aluminium
EN AW	1095	Europe	EN designation mirrors AA nomenclature for high‑purity wrought product
JIS	A1095	Japan	Japanese Industrial Standard equivalent used in domestic specifications
GB/T	1095	China	Chinese standard designation aligned with international naming conventions

Equivalent grade designations are broadly consistent because 1xxx series alloys are defined by their aluminium minimum and strict impurity limits. However, tolerance bands for trace elements and permitted impurity levels can vary slightly by standard, which affects electrical conductivity, recrystallization behavior and formability in tight‑tolerance applications. For critical electrical or foil applications, always verify the specific standard and supplier’s certified composition and properties.

Corrosion Resistance

1095 exhibits excellent general atmospheric corrosion resistance due to the high aluminium content and absence of aggressive alloying elements. Its natural oxide film provides passivation and protection in many environments; however localized attack can occur in polluted atmospheric conditions or acid environments. Regular maintenance and appropriate surface finishes (anodizing or cladding) further enhance long‑term performance.

In marine environments the alloy performs reasonably well in terms of uniform corrosion; nonetheless, chloride‑induced pitting and crevice corrosion are more effectively resisted by specific marine‑grade alloys (e.g., 5xxx series). Galvanic interactions must be managed: 1095 is anodic relative to copper and stainless steels and can corrode sacrificially when in electrical contact with more noble materials unless insulating measures or compatible fasteners are used.

Stress corrosion cracking incidence is low for high‑purity aluminium alloys because they lack high concentrations of alloying elements that promote SCC. When compared with 5xxx and 6xxx families, 1095 trades some localized corrosion resistance for higher conductivity and ductility, while offering superior overall corrosion stability versus many heat‑treatable high‑strength alloys that contain copper or zinc.

Fabrication Properties

Weldability

1095 welds readily with TIG, MIG and resistance welding processes because of its low alloy content and high thermal conductivity. Weld filler selection commonly uses matching-purity filler or Al‑pure welding rods; copper‑bearing fillers are avoided to preserve corrosion resistance. Hot‑cracking risk is low but shrinkage stresses and HAZ softening can be significant, requiring pre‑ and post‑weld control of distortion and, where needed, mechanical compensation. Welds can show reduced mechanical properties near the fusion zone due to recovery and recrystallization of cold work.

Machinability

Machinability of 1095 is moderate to good; the soft matrix and ductile chips demand sharp tooling and chip breakers for efficient cutting. Tool steels such as carbide tipped cutters and high‑speed steel with positive geometry perform well; cutting speeds should consider high thermal conductivity which quickly dissipates heat from the cut zone. Surface finish achieves high quality with low tool wear, but care must be taken to avoid gummy chips in low‑speed, heavy‑depth cuts. Abrasive wear on tools is minimal compared with high‑silicon aluminium alloys.

Formability

Formability in O condition is excellent, permitting deep drawing, spinning, and complex stamping with relatively large bend reductions. Minimum bend radii depend on temper and thickness; in O the recommended inside bend radii can be as low as 0.5–1.0×thickness for many operations, while H‑tempers require larger radii and may necessitate intermediate anneals. Cold work increases yield and reduces elongation, so staged forming with intermediate stress relief is common for complex shapes. For tight radius bending or severe stretch forming, annealed or lightly strain‑hardened tempers are preferred.

Heat Treatment Behavior

As a non‑heat‑treatable alloy, 1095 does not respond to solution treatment and aging for strengthening; there are no precipitation hardening steps that meaningfully increase strength. Strength adjustments are made via cold work (strain hardening) and controlled annealing. Typical annealing treatments for full softening are carried out at temperatures in the range of ~300–420 °C with soak times that depend on gauge, producing the O temper and restoring ductility and conductivity.

Tempering transitions are expressed as degrees of work hardening (H12, H14, H16, H18), and temper selection is achieved by specified amounts of rolling, drawing or bending reductions. Over‑annealing or excessive thermal exposure during fabrication (welding, brazing) causes recrystallization and softening, which must be accounted for in component design and joint planning.

High-Temperature Performance

1095 exhibits significant strength reduction at elevated temperatures compared with room temperature; useful load‑bearing capacity falls progressively above 100 °C and is typically limited for continuous service above ~150 °C. Oxidation is modest because aluminium forms a stable oxide layer, but surface scaling is minimal relative to steels and high‑temperature alloys. Thermal cycles and exposure to elevated process temperatures can anneal cold‑worked tempers locally, particularly in welded HAZ regions, leading to permanent softening and dimensional instability.

Designers should therefore limit continuous operating temperatures and account for creep under sustained loads when temperatures exceed 100 °C. For short thermal excursions the alloy retains reasonable integrity, but long‑term mechanical or fatigue life can be compromised by high‑temperature exposure and should be validated by application‑specific testing.

Applications

Industry	Example Component	Why 1095 Is Used
Electrical/Power	Busbars, electrical conductors	High electrical conductivity and formability
Heat Transfer	Heat sinks, fin stock	High thermal conductivity and low density
Chemical Processing	Cladding, tanks	High corrosion resistance to many chemicals
Architectural	Decorative panels, curtain walls	Surface finishability and corrosion stability
Consumer Goods	Foil, reflectors, cookware	Excellent formability and surface quality

1095 finds frequent use where the combination of near‑pure aluminium properties matters more than high strength: conductivity, thermal performance, corrosion resistance and formability. Components that require extensive forming, tight radii, excellent surface finish or electrical performance are natural fits for 1095, particularly when coupled with cost and availability priorities.

Selection Insights

Choose 1095 when the design priorities are high electrical or thermal conductivity, superior formability and excellent general corrosion resistance rather than peak strength. Its purity makes it attractive for busbars, heat‑transfer elements and decorative or cladding applications where surface finish and conductivity trump mechanical load capacity.

Compared with commercially pure aluminium like 1100, 1095 offers comparable or slightly higher purity and similar formability, trading little in conductivity while sometimes requiring tighter control of residuals for specialized electrical uses. Compared with work‑hardened alloys such as 3003 or 5052, 1095 generally offers higher conductivity and similar or superior formability but lower strength and less resistance to localized sea‑water pitting than Mg‑alloyed 5xxx grades. Compared with heat‑treatable structural alloys like 6061 or 6063, 1095 is selected when conductivity and formability are prime over achievable peak strength; it is preferred for electrical or thermal roles and for components requiring repeated forming or very high surface quality.

Closing Summary

1095 remains relevant where near‑pure aluminium performance is required: excellent conductivity, superior formability and intrinsic corrosion resistance combined with low density. Its role is complementary to higher‑strength and precipitation‑hardened alloys, making it a staple material for electrical, thermal and chemically exposed applications where purity and ductility are decisive.