Aluminum 7085 · temper
Aluminum 7085-T7651
Properties of the T7651 condition, compared with the other 7085 tempers.
Choose when static strength and exfoliation resistance matter more than maximum toughness — upper wing covers, compression-dominated plate parts.
What is 7085-T7651?
7085-T7651 is 7085 in the T7651 temper — choose when static strength and exfoliation resistance matter more than maximum toughness — upper wing covers, compression-dominated plate parts. 7085-T7651 has a yield strength of 496 MPa (71.9 ksi) and a tensile strength of 531 MPa (77 ksi) — stronger than 96% of aluminum grades. Elongation at break is 9% and the elastic modulus is 70.5 GPa (10.2 Msi). 7085-T7651 has a density of 2.85 g/cm³ (0.103 lb/in³), heavier than 95% of aluminum grades. It melts at 477°C (891 °F). T7451 is the default condition FabDigit quotes; T7651 is available on request or by drawing note.
Advantages
- High strength — 496 MPa (71.9 ksi), better than 96% of aluminum grades
- Tough — resists crack growth — 33 MPa·√m (30 ksi·√in), better than 88% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Difficult to weld — 20/100, worse than 89% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
7085-T7651 properties
Typical room-temperature values for 7085-T7651 — 13 properties are specific to this condition; the rest are grade-level values shared by every 7085 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
7085-T7651 has a density of 2.85 g/cm³ (0.103 lb/in³), heavier than 95% of aluminum grades. It melts at 477°C (891 °F).
Mechanical13
7085-T7651 has a yield strength of 496 MPa (71.9 ksi) and a tensile strength of 531 MPa (77 ksi) — stronger than 96% of aluminum grades. Elongation at break is 9% and the elastic modulus is 70.5 GPa (10.2 Msi).
Thermal6
7085-T7651 is rated for continuous service to 120°C (248 °F). It conducts heat at 145 W/m·K (83.8 BTU/hr·ft·°F), better than 53% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
7085-T7651 conducts electricity at 39 % IACS, better than 65% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of 7085-T7651 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 75% of aluminum grades. Typical recycled content is 8%.
Manufacturability8
7085-T7651's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (20/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 7085 tempers and conditions
7085 is also supplied in 5 other conditions. The full side-by-side table is on the 7085 overview.
- T7451DefaultDefault thick-plate condition: best overall balance of strength, fracture toughness and SCC resistance for machined wing/fuselage structural parts.469 MPa yield · 150 HB
- T7651XExtrusion condition for 7085 stringers/stiffeners needing high compressive yield plus exfoliation resistance.517 MPa yield · 160 HB
- T7651Choose when static strength and exfoliation resistance matter more than maximum toughness — upper wing covers, compression-dominated plate parts.496 MPa yield · 158 HB
- T7452The standard condition for large 7085 die and hand forgings (bulkheads, landing-gear support ribs) where stress relief is done by cold compression rather than stretching.462 MPa yield · 148 HB
- T7351Pick when maximum fracture toughness and stress-corrosion resistance dominate over strength — thick plate for damage-tolerant fuselage frames and bulkheads.428 MPa yield · 138 HB
- T7352Forging counterpart of T7351 — maximum SCC/toughness margin in heavy sections at the cost of ~8 % strength.421 MPa yield · 136 HB
Working with 7085-T7651
Is 7085 easy to machine?
Machines very freely in T74/T76 tempers with sharp polished carbide, high speed and flood coolant; large stock removal from thick plate needs symmetric passes and stress-relieved (T7x51/T7x52) material to control distortion.
Can 7085 be welded?
Not fusion weldable (hot cracking, drastic HAZ property loss) — join by riveting, bolting or friction stir welding with post-weld property allowance.
Can 7085 be formed, bent or molded?
Formed hot as thick plate or die forging; in the aged temper only mild bending/straightening is possible — do stretch/compression stress relief before machining.
What surface finishes work on 7085?
Chromic or boric-sulfuric anodize plus epoxy primer for aerospace corrosion protection; hard anodize possible but grey-tinted, and shot peening or Alclad/paint systems are used on exposed surfaces.
7085 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 | ≤ 0.06 | 0.03 |
| Femax — kept very low for toughness | ≤ 0.08 | 0.05 |
| Cu | 1.3 – 2 | 1.6 |
| Mn | ≤ 0.04 | 0.01 |
| Mg | 1.2 – 1.8 | 1.5 |
| Cr | ≤ 0.04 | 0.01 |
| Zn | 7 – 8 | 7.5 |
| Ti | ≤ 0.06 | 0.03 |
| Zrdispersoid former, replaces Cr/Mn | 0.08 – 0.15 | 0.11 |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
7085-T7651 — frequently asked
What is 7085-T7651 used for?
7085-T7651 is typically used for aerospace heavy forgings, wing spars, fuselage and wing bulkheads, machined wing ribs and frames, landing gear structural fittings and thick-plate airframe fittings. In short: ultra-thick aerospace forging; low quench sensitivity.
What is the yield strength of 7085-T7651?
7085-T7651 has a typical yield strength of 496 MPa (71.9 ksi) and a tensile strength of 531 MPa (77 ksi) — stronger than 96% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 7085-T7651 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines very freely in T74/T76 tempers with sharp polished carbide, high speed and flood coolant; large stock removal from thick plate needs symmetric passes and stress-relieved (T7x51/T7x52) material to control distortion.
Can 7085-T7651 be welded?
Not readily — weldability is rated poor (20/100). Not fusion weldable (hot cracking, drastic HAZ property loss) — join by riveting, bolting or friction stir welding with post-weld property allowance.
What surface finishes work on 7085-T7651?
Chromic or boric-sulfuric anodize plus epoxy primer for aerospace corrosion protection; hard anodize possible but grey-tinted, and shot peening or Alclad/paint systems are used on exposed surfaces.
Can 7085-T7651 be formed, bent or molded?
Formed hot as thick plate or die forging; in the aged temper only mild bending/straightening is possible — do stretch/compression stress relief before machining.
What is the maximum service temperature of 7085-T7651?
7085-T7651 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 7085-T7451 and 7085-T7352?
T7451 is the default condition — default thick-plate condition: best overall balance of strength, fracture toughness and SCC resistance for machined wing/fuselage structural parts. T7352: forging counterpart of T7351 — maximum SCC/toughness margin in heavy sections at the cost of ~8 % strength. Yield strength is 469 MPa in T7451 versus 421 MPa in T7352.
Can FabDigit make parts in 7085-T7651?
Yes — 7085-T7651 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)
- AMS 4413 / AMS 4414 — Aluminum Alloy 7085 Plate and Die Forgings — SAE International (2016)
- Alcoa 7085 thick plate and forgings product information — Alcoa / Arconic (2010)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- MMPDS-17 Metallic Materials Properties Development and Standardization — Battelle / FAA (2022)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.