2011 Aluminum

Representative aluminum raw/semi-finished material photo; exact grade not verified

Image Credit: alro.com

2011 Aluminum (AA 2011, UNS A92011) is a wrought aluminum–copper free-machining alloy developed for high-volume production of intricate turned parts. Its approximately 5–6% copper content allows heat-treatment strengthening, while lead and bismuth additions promote short, easily controlled chips during cutting. The alloy is consequently a strong choice for automatic screw machines, precision fittings, and small machined hardware. It is not a general-purpose corrosion-resistant or weldable alloy: the same free-machining additions that aid chip control limit its suitability for welded structures and demanding corrosive environments. Mechanical properties depend substantially on product form and temper.

Chemical Composition (wt.%)
Chemical Composition wt.%
Element	Min	Max
Silicon	—	0.40
Iron	—	0.70
Copper	5.0	6.0
Zinc	—	0.30
Aluminum	Balance

Composition notes

Silicon: Registered maximum composition limit.
Iron: Registered maximum composition limit.
Copper: Registered composition range.
Zinc: Registered maximum composition limit.
Aluminum: Remainder in the registered composition listing; AZoM reports a nominal aluminum content of 93.7%.

Registered AA composition limits are shown where clearly visible in the Aluminum Association record. The AZoM values for bismuth, lead, copper, and aluminum are reported nominal composition values, not registered limits. The registered table excerpt identifies aluminum as the remainder/balance; incomplete excerpted fields have not been reconstructed as numerical limits.

Values below are source-reported general alloy data. Thermal conductivity is specifically reported for T3 temper at 25 °C; density is reported as a nominal physical value. Strength values are deliberately omitted because no supplied source provides product-form- and temper-qualified tensile data for AA 2011.

Use the button to switch between Metric and US Customary units.

Table of 2011 Aluminum Properties

Table of 2011 Aluminum Properties
Physical Properties	Metric
Density	2.82 g/cm³2.82 g/cm³
Mechanical Properties	Metric
Elastic modulus	70–80 GPa
Poisson's ratio	0.33
Thermal Properties	Metric
Coefficient of thermal expansion (20–100 °C)	23 ×10⁻⁶/°C
Thermal conductivity	152 W/(m·K)

Test conditions & data notes

Density: Nominal value
Elastic modulus: General alloy value
Poisson's ratio: General alloy value
Thermal conductivity: 25 °C, T3 temper

Material Conditions & Tempers

2011 is supplied in condition-specific wrought product forms, and temper must be stated with the order because it controls strength, ductility, straightness, and machining response. T3 is specifically associated with the reported thermal-conductivity value. The supplied source also describes a T8 route following solution heat treatment, quenching, cold work, and artificial aging. Confirm dimensional tolerances and minimum mechanical properties against the applicable product standard and supplier certification.

Condition	Description	Notes
T3	Solution heat-treated, cold worked, and naturally aged condition used for wrought aluminum products.	Thermal conductivity of 152 W/(m·K) at 25 °C is reported for T3; no strength value is provided in the supplied sources.
T8	Solution heat-treated, cold worked, and artificially aged condition intended to develop higher strength after cold work.	The supplied AZoM source describes artificial aging after solution treatment and quenching; qualified strength depends on product form and specification.
O	Annealed condition used when maximum softness and forming latitude are required before subsequent processing.	Annealing practice must be controlled to the applicable product specification and section size.

Advantages & Limitations

Advantages	Limitations
Excellent free-machining behavior for automatic lathes and multi-spindle screw-machine work; lead and bismuth help produce short chips. Copper-bearing 2xxx-series chemistry permits strengthening by solution treatment, cold work, and aging. Well suited to close-tolerance, small-to-medium precision components where machining cycle time and chip control matter. Low density relative to steel supports lightweight fittings, stems, and machined hardware. Readily processed by conventional cold-working and forming methods when the selected temper provides sufficient ductility.	Corrosion resistance is inferior to many non-heat-treatable aluminum alloys; consider coatings, plating, lubrication, or a more corrosion-resistant alloy for wet or aggressive service. Welding is not recommended by the supplied technical source; do not select 2011 for welded structural assemblies. Lead and bismuth additions can restrict use where lead-free material, food-contact compliance, or stringent environmental requirements apply. Strength, fatigue behavior, and formability are temper- and product-form-dependent; a grade-only strength value is not adequate for design. Elevated-temperature service can reduce aluminum-alloy strength; verify performance at the actual operating temperature.

Advantages

Limitations

Excellent free-machining behavior for automatic lathes and multi-spindle screw-machine work; lead and bismuth help produce short chips.
Copper-bearing 2xxx-series chemistry permits strengthening by solution treatment, cold work, and aging.
Well suited to close-tolerance, small-to-medium precision components where machining cycle time and chip control matter.
Low density relative to steel supports lightweight fittings, stems, and machined hardware.
Readily processed by conventional cold-working and forming methods when the selected temper provides sufficient ductility.

Corrosion resistance is inferior to many non-heat-treatable aluminum alloys; consider coatings, plating, lubrication, or a more corrosion-resistant alloy for wet or aggressive service.
Welding is not recommended by the supplied technical source; do not select 2011 for welded structural assemblies.
Lead and bismuth additions can restrict use where lead-free material, food-contact compliance, or stringent environmental requirements apply.
Strength, fatigue behavior, and formability are temper- and product-form-dependent; a grade-only strength value is not adequate for design.
Elevated-temperature service can reduce aluminum-alloy strength; verify performance at the actual operating temperature.

Processing & Fabrication

Process	Description
Machining	2011 is principally selected as a free-machining alloy. High-speed steel or carbide tooling may be used; the supplied source notes dry cutting for light cuts and oil for heavier cuts. Optimize tooling, coolant, and chip evacuation for the part geometry and machine.
Cold working and forming	Conventional bending, forming, and shaping methods can be used. Choose a temper compatible with the required deformation, then use a qualified heat-treatment route if strengthening after forming is required.
Annealing	The supplied source describes holding at 413 °C (775 °F) for 2–3 hours, controlled cooling at 10 °C (50 °F) per hour to 260 °C (500 °F), then air cooling. Treat this as guidance only; production cycles require validation for product form and section size.
Hot working and forging	The supplied source gives a hot-working/forging range of 288–482 °C (550–900 °F). Use controlled heating and a qualified shop practice to avoid overheating and preserve workable microstructure.
Solution treatment and aging	The supplied source describes solution heat treatment at 510 °C (950 °F), water quenching, cold work as required, and artificial aging at 160 °C (320 °F) for about 14–15 hours for a T8-type condition. Establish final practice through the applicable specification and supplier guidance.
Welding	Welding is not recommended by the supplied source. Where joining is unavoidable, evaluate a mechanical fastening or redesign option before developing a qualified welding procedure.

Applications

2011 Aluminum is used where machining productivity, chip control, and repeatable precision outweigh corrosion resistance and weldability. It is especially appropriate for bar-stock parts made in volume on automatic screw machines, CNC turning centers, and transfer equipment.

Automatic screw-machine components: Its free-machining chemistry supports efficient production of complex turned profiles, drilled features, and threads with controllable chips.
Tube fittings and pipe stems: The alloy is suitable for compact precision fittings that benefit from rapid turning, threading, and dimensional repeatability.
Hose and atomizer parts: Small detailed components can be machined economically from 2011 bar stock; service environment should be reviewed for corrosion risk.
Precision machine parts: Pins, collars, bushings, spacers, and similar non-welded components benefit from the alloy's machining performance and heat-treatable copper-bearing base.
Lightweight instrument and hardware components: Where low mass and production-rate machining are priorities, 2011 can provide a practical alternative to more difficult-to-machine high-strength aluminum alloys.

Standards & Designations

Designation	Value	Description
Aluminum Association	AA 2011	Registered wrought aluminum alloy designation; the Aluminum Association Teal Sheets list 2011 as a U.S. designation registered in 1954.
UNS	UNS A92011	Designation identified by the supplied AZoM technical page.
Aluminum Association composition record	International Alloy Designation 2011	Chemical composition limits are listed in the Aluminum Association International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys.

Frequently Asked Questions

Why is 2011 Aluminum called a free-machining alloy?

2011 combines a copper-bearing aluminum base with lead and bismuth additions that improve chip breaking and cutting behavior. This makes it particularly effective for high-rate turning, drilling, threading, and automatic screw-machine production.

Can 2011 Aluminum be welded?

It is generally a poor choice for welded construction. The supplied technical source explicitly does not recommend welding 2011. For welded aluminum assemblies, select a grade designed for weldability and qualify the joint for the intended service.

Is 2011 Aluminum suitable for outdoor or corrosive service?

Not without careful assessment. Compared with many general-purpose aluminum alloys, 2011 has relatively limited corrosion resistance. Protective finishing and isolation from dissimilar metals may help, but a more corrosion-resistant alloy is often the better material choice for sustained wet, marine, or chemically aggressive exposure.

References & Data Notes

(n.d.). The Aluminum Association — International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys, revised December 2025. https://www.aluminum.org/sites/default/files/2026-01/Teal%20Sheets%20December%202025.pdf
(n.d.). AZoM — Aluminium / Aluminum 2011 alloy (UNS A92011). https://www.azom.com/article.aspx?ArticleID=6613

Composition values marked as registered are drawn from the supplied Aluminum Association record. The source excerpt does not expose all fields for the 2011 row, so no unverified registered limits were added. Nominal bismuth and lead values come from AZoM and must not be treated as procurement limits. Confirm chemistry, product form, temper, mechanical requirements, dimensional tolerances, and regulatory suitability from the governing specification and mill test certificate.