Aluminum 7068-T6
Temper
AA 7068 · UNS A97068
T6 = solution heat treated and artificially aged
Peak-strength temper for forgings and non-stress-relieved product where maximum static strength is wanted.
Values for the T6 condition
Other 7068 tempers and conditions
7068 is listed in 7 conditions; see the grade overview at 7068.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Soft fabrication condition for heavy forming or straightening before re-heat-treatment; never used as a service temper. | 110 | 230 | 14 | 60 HB | 42 % IACS |
Solution treated, stretched, fully overaged for maximum SCC resistance | Special-order overaged condition for the most SCC-critical parts; strength drops toward 7075-T73 levels so it is rarely specified for 7068. | 555 | 600 | 12 | 160 HB | 39 % IACS |
Solution treated, stretched, overaged for exfoliation/SCC resistance | Pick when exfoliation and stress-corrosion resistance are required and ~7 % strength loss versus T6511 is acceptable. | 620 | 655 | 11 | 175 HB | 36 % IACS |
T6, stress relieved by stretching | Use for flat rolled or machined plate/bar where low residual stress and dimensional stability during machining matter. | 670 | 700 | 10 | 185 HB | 31 % IACS |
T6This page Solution heat treated and artificially aged | Peak-strength temper for forgings and non-stress-relieved product where maximum static strength is wanted. | 676 | 705 | 10 | 188 HB | 31 % IACS |
T6511Default T6, stress relieved by stretching, minor straightening | The standard stocked condition for 7068 extruded rod/bar/shapes — maximum strength with controlled residual stress. | 683 | 710 | 11 | 190 HB | 31 % IACS |
Solution treated, stress-relieved by stretching, aged; no further… | Extruded shapes/bar with minimum residual stress and no post-stretch straightening — best choice for symmetric heavy machining. | 683 | 710 | 11 | 190 HB | 31 % IACS |
What is 7068-T6?
7068-T6 is 7068 in the T6 temper — peak-strength temper for forgings and non-stress-relieved product where maximum static strength is wanted. 7068-T6 has a yield strength of 676 MPa (98 ksi) and a tensile strength of 705 MPa (102 ksi) — stronger than 100% of aluminum grades. Elongation at break is 10% and the elastic modulus is 73 GPa (10.6 Msi). 7068-T6 has a density of 2.85 g/cm³ (0.103 lb/in³), heavier than 96% of aluminum grades. It melts at 476°C (889 °F). T6511 is the default condition FabDigit quotes; T6 is available on request or by drawing note.
Advantages
- High strength — 676 MPa (98 ksi), better than 100% of aluminum grades
- Polishes to a fine finish — 65/100, better than 82% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Needs corrosion protection — 30/100, worse than 98% of aluminum grades
- Difficult to weld — 12/100, worse than 98% of aluminum grades
- Limited formability — 10/100, worse than 80% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
7068-T6 properties
Typical room-temperature values for 7068-T6; 12 are specific to this condition. Other listed values are 7068 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
7068-T6 has a density of 2.85 g/cm³ (0.103 lb/in³), heavier than 96% of aluminum grades. It melts at 476°C (889 °F).
Mechanical13
7068-T6 has a yield strength of 676 MPa (98 ksi) and a tensile strength of 705 MPa (102 ksi) — stronger than 100% of aluminum grades. Elongation at break is 10% and the elastic modulus is 73 GPa (10.6 Msi).
Thermal6
7068-T6 is rated for continuous service to 120°C (248 °F). It conducts heat at 155 W/m·K (89.6 BTU/hr·ft·°F), better than 71% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
7068-T6 conducts electricity at 31 % IACS, worse than 68% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (30/100), worse than 98% of aluminum grades.
Sustainability4
Producing a kilogram of 7068-T6 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 5%.
Manufacturability7
7068-T6's machinability is very good (72/100, better than 80% of aluminum grades); weldability not recommended (12/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7068-T6
Is 7068 easy to machine?
Machines well with sharp carbide, high speed and polished flutes (like 7075 but with higher cutting forces and springback); use flood or MQL coolant and choose T6510/T651 for low residual stress on thin-walled parts.
Can 7068 be welded?
Not recommended for fusion welding (hot cracking and severe HAZ strength/SCC loss); join by fasteners, adhesives, or friction-stir/friction welding with post-weld aging where qualified.
Can 7068 be formed, bent or molded?
Essentially no cold forming in T6x — bend or form in O/W (as-quenched) condition and re-age; supplied mainly as extrusions and die forgings hot-worked at ~370–430 °C.
What surface finishes work on 7068?
Anodizes well including Type III hard coat (shade runs slightly grey/dark); protect short-transverse machined surfaces with anodize + primer to limit stress-corrosion and exfoliation risk, or specify a T76 temper.
7068 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 |
|---|---|---|
| Znprimary strengthening addition | 7.3 – 8.3 | 7.8 |
| Mg | 2.2 – 3 | 2.6 |
| Cu | 1.6 – 2.4 | 2 |
| Zrgrain-structure control (recrystallization inhibitor) | 0.05 – 0.15 | 0.1 |
| Si | ≤ 0.12 | — |
| Fe | ≤ 0.15 | — |
| Mn | ≤ 0.1 | — |
| Cr | ≤ 0.05 | — |
| Ti | ≤ 0.01 | — |
| Others (each)0.15 max total | ≤ 0.05 | — |
| Al | balance | — |
7068-T6 — frequently asked
What is 7068-T6 used for?
7068-T6 is typically used for bicycle components, sporting goods (golf clubs, bats), high-strength fasteners and military components. In short: highest-strength aluminum extrusion; stronger than 7075-T6; not fusion weldable.
What is the yield strength of 7068-T6?
7068-T6 has a typical yield strength of 676 MPa (98 ksi) and a tensile strength of 705 MPa (102 ksi) — stronger than 100% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is 7068-T6 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well with sharp carbide, high speed and polished flutes (like 7075 but with higher cutting forces and springback); use flood or MQL coolant and choose T6510/T651 for low residual stress on thin-walled parts.
Can 7068-T6 be welded?
Not readily — weldability is rated not recommended (12/100). Not recommended for fusion welding (hot cracking and severe HAZ strength/SCC loss); join by fasteners, adhesives, or friction-stir/friction welding with post-weld aging where qualified.
What surface finishes work on 7068-T6?
Anodizes well including Type III hard coat (shade runs slightly grey/dark); protect short-transverse machined surfaces with anodize + primer to limit stress-corrosion and exfoliation risk, or specify a T76 temper.
Can 7068-T6 be formed, bent or molded?
Essentially no cold forming in T6x — bend or form in O/W (as-quenched) condition and re-age; supplied mainly as extrusions and die forgings hot-worked at ~370–430 °C.
What is the maximum service temperature of 7068-T6?
7068-T6 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 7068-T6511 and 7068-O?
T6511 is the default condition — the standard stocked condition for 7068 extruded rod/bar/shapes — maximum strength with controlled residual stress. O: soft fabrication condition for heavy forming or straightening before re-heat-treatment; never used as a service temper. Yield strength is 683 MPa in T6511 versus 110 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- 7068 Extruded Rod, Bar and Shapes — Alloy Data — Kaiser Aluminum (2020)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- MMPDS (Metallic Materials Properties Development and Standardization) — Battelle/FAA (2023)
- MatWeb aluminium 7068-T6511 data record — MatWeb LLC (2024)
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.