Aluminum 7085 · temper · default condition
Aluminum 7085-T7451
Properties of the T7451 condition, compared with the other 7085 tempers.
Default thick-plate condition: best overall balance of strength, fracture toughness and SCC resistance for machined wing/fuselage structural parts.
What is 7085-T7451?
7085-T7451 is 7085 in the T7451 temper — default thick-plate condition: best overall balance of strength, fracture toughness and SCC resistance for machined wing/fuselage structural parts. 7085-T7451 has a yield strength of 469 MPa (68 ksi) and a tensile strength of 505 MPa (73.2 ksi) — stronger than 93% of aluminum grades. Elongation at break is 11% and the elastic modulus is 70.5 GPa (10.2 Msi). 7085-T7451 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).
Advantages
- Tough — resists crack growth — 38 MPa·√m (34.6 ksi·√in), better than 96% of aluminum grades
- High strength — 469 MPa (68 ksi), better than 93% of aluminum grades
- High electrical conductivity — 41 % IACS, better than 78% 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-T7451 properties
Typical room-temperature values for 7085-T7451 — 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-T7451 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-T7451 has a yield strength of 469 MPa (68 ksi) and a tensile strength of 505 MPa (73.2 ksi) — stronger than 93% of aluminum grades. Elongation at break is 11% and the elastic modulus is 70.5 GPa (10.2 Msi).
Thermal6
7085-T7451 is rated for continuous service to 120°C (248 °F). It conducts heat at 152 W/m·K (87.8 BTU/hr·ft·°F), better than 66% of aluminum grades. Thermal expansion is 23.4 µm/m·K (13 µin/in·°F).
Electrical3
7085-T7451 conducts electricity at 41 % IACS, better than 78% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 56% of aluminum grades.
Sustainability4
Producing a kilogram of 7085-T7451 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-T7451's machinability is very good (70/100, better than 72% of aluminum grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
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-T7451
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-T7451 — frequently asked
What is 7085-T7451 used for?
7085-T7451 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-T7451?
7085-T7451 has a typical yield strength of 469 MPa (68 ksi) and a tensile strength of 505 MPa (73.2 ksi) — stronger than 93% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 7085-T7451 easy to machine?
Yes — machinability is rated very good (70/100, better than 72% 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-T7451 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-T7451?
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-T7451 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-T7451?
7085-T7451 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-T7451?
Yes — 7085-T7451 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.