Aluminum 2011-T851
Temper
AA 2011 · UNS A92011 · EN AlCu6BiPb, AW-2011 · also FC1
T851 = t8, stress relieved by stretching
T8 strength in a stress-relieved bar; best choice for long slender turned components.
Values for the T851 condition
Other 2011 tempers and conditions
2011 is listed in 10 conditions; see the grade overview at 2011.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest state, used only as an intermediate condition before further working or heat treatment. | 90 | 165 | 25 | 45 HB | 45 % IACS |
T4, stress relieved by stretching | T4 strength with low residual stress; preferred where thin-wall parts must stay dimensionally stable after machining. | 193 | 324 | 18 | 85 HB | 39 % IACS |
Solution heat treated and naturally aged | Use when some cold forming or staking is needed after machining, or as the starting point for T8 ageing. | 193 | 324 | 18 | 85 HB | 39 % IACS |
Solution heat treated, cold worked, stress relieved by stretching | Choose for long drawn bars where straightness and low residual stress matter for CNC turning. | 290 | 379 | 15 | 95 HB | 39 % IACS |
T6, stress relieved by stretching | T6 properties with relieved residual stress for stable precision machined parts. | 290 | 385 | 12 | 100 HB | 44 % IACS |
Solution heat treated, cold worked and naturally aged | The standard stocked condition for 2011 free-machining rod and bar; best all-round strength/chip-forming combination. | 296 | 379 | 15 | 95 HB | 39 % IACS |
Solution heat treated and artificially aged | Pick when maximum hardness and thermal stability are needed without prior cold work. | 296 | 390 | 12 | 100 HB | 44 % IACS |
T851This page T8, stress relieved by stretching | T8 strength in a stress-relieved bar; best choice for long slender turned components. | 305 | 400 | 12 | 100 HB | 45 % IACS |
T8 with stress relief by stretching, minor straightening permitted | Commercial straightened version of T851 for drawn/extruded bar supplied to automatic lathes. | 305 | 400 | 12 | 100 HB | 45 % IACS |
Solution heat treated, cold worked and artificially aged | Highest strength and best dimensional/thermal stability for 2011; standard for high-load turned fittings. | 310 | 407 | 12 | 100 HB | 45 % IACS |
What is 2011-T851?
2011-T851 is 2011 in the T851 temper — t8 strength in a stress-relieved bar; best choice for long slender turned components. 2011-T851 has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 77% of aluminum grades. Elongation at break is 12% and the elastic modulus is 70 GPa (10.2 Msi). 2011-T851 has a density of 2.83 g/cm³ (0.102 lb/in³), heavier than 91% of aluminum grades. It melts at 541°C (1,006 °F).
Advantages
- Easy to machine — 100/100, better than 100% of aluminum grades
- High electrical conductivity — 45 % IACS, better than 86% of aluminum grades
- Conducts heat well — 173 W/m·K (100 BTU/hr·ft·°F), better than 84% of aluminum grades
- High strength — 305 MPa (44.2 ksi), better than 77% of aluminum grades
Limitations
- Needs corrosion protection — 25/100, worse than 100% of aluminum grades
- Difficult to weld — 10/100, worse than 99% of aluminum grades
2011-T851 properties
Typical room-temperature values for 2011-T851; 19 are specific to this condition. Other listed values are 2011 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2011-T851 has a density of 2.83 g/cm³ (0.102 lb/in³), heavier than 91% of aluminum grades. It melts at 541°C (1,006 °F).
Mechanical11
2011-T851 has a yield strength of 305 MPa (44.2 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 77% of aluminum grades. Elongation at break is 12% and the elastic modulus is 70 GPa (10.2 Msi).
Thermal6
2011-T851 is rated for continuous service to 150°C (302 °F). It conducts heat at 173 W/m·K (100 BTU/hr·ft·°F), better than 84% of aluminum grades. Thermal expansion is 22.9 µm/m·K (12.7 µin/in·°F).
Electrical3
2011-T851 conducts electricity at 45 % IACS, better than 86% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), worse than 100% of aluminum grades.
Sustainability4
Producing a kilogram of 2011-T851 takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.
Manufacturability7
2011-T851's machinability is excellent (100/100, better than 100% of aluminum grades); weldability not recommended (10/100); formability poor (18/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2011-T851
Is 2011 easy to machine?
Benchmark free-cutting aluminium: fine broken chips, excellent surface finish and long tool life at very high sfm; ideal for Swiss/automatic lathes.
Can 2011 be welded?
Essentially not weldable by fusion or brazing — Bi/Pb low-melting phases cause severe hot cracking; join mechanically or with adhesives.
Can 2011 be formed, bent or molded?
Poor cold formability, especially in T3/T8; avoid tight bends, staking or riveting — form in T4/O only with generous radii.
What surface finishes work on 2011?
Chromate/phosphate conversion coatings and paint work well; clear anodize is grey/mottled from Cu and Bi/Pb inclusions, hard anodize possible but non-uniform; electroplating requires careful pretreatment.
2011 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Si | ≤ 0.4 | — |
| Fe | ≤ 0.7 | — |
| Cu | 5 – 6 | 5.5 |
| Zn | ≤ 0.3 | — |
| Bichip-breaking phase | 0.2 – 0.6 | 0.4 |
| Pbchip-breaking phase; RoHS exemption often required | 0.2 – 0.6 | 0.4 |
| Others (each)each | ≤ 0.05 | — |
| Others (total)total | ≤ 0.15 | — |
| Al | balance | — |
2011-T851 — frequently asked
What is 2011-T851 used for?
2011-T851 is typically used for screw machine parts, threaded fasteners and studs, hose, pipe and hydraulic fittings, pneumatic and valve components, precision pins, bushings and spacers and instrument knobs and adjusting screws. In short: fastest machining aluminum.
What is the yield strength of 2011-T851?
2011-T851 has a typical yield strength of 305 MPa (44.2 ksi) and a tensile strength of 400 MPa (58 ksi) — stronger than 77% of aluminum grades. Strength varies by condition: see the 10 listed tempers.
Is 2011-T851 easy to machine?
Yes — machinability is rated excellent (100/100, better than 100% of aluminum grades). Benchmark free-cutting aluminium: fine broken chips, excellent surface finish and long tool life at very high sfm; ideal for Swiss/automatic lathes.
Can 2011-T851 be welded?
Not readily — weldability is rated not recommended (10/100). Essentially not weldable by fusion or brazing — Bi/Pb low-melting phases cause severe hot cracking; join mechanically or with adhesives.
What surface finishes work on 2011-T851?
Chromate/phosphate conversion coatings and paint work well; clear anodize is grey/mottled from Cu and Bi/Pb inclusions, hard anodize possible but non-uniform; electroplating requires careful pretreatment.
Can 2011-T851 be formed, bent or molded?
Poor cold formability, especially in T3/T8; avoid tight bends, staking or riveting — form in T4/O only with generous radii.
What is the maximum service temperature of 2011-T851?
2011-T851 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in 2011-T851?
Yes — 2011-T851 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASTM B211 — Aluminum-Alloy Rolled or Cold Finished Bar, Rod, and Wire — ASTM (2019)
- EN 573-3 / EN 754-2 (EN AW-2011, AlCu6BiPb) — CEN (2019)
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys — ASM International (1990)
- Aluminum Standards and Data (typical mechanical/physical property tables) — The Aluminum Association (2017)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.