Aluminum 7475
AA 7475 · UNS A97475 · EN AW-7475, AW 7475
7475 is a high-purity Al-Zn-Mg-Cu aerospace alloy derived from 7075 with tightly controlled Fe and Si and optimised processing, which raises fracture toughness and resistance to fatigue crack growth while holding 7075-level strength.
7475 tempers and conditions
7475 is supplied in 10 conditions, soft to hard.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for severe forming or machining before solution treatment. | 105 | 228 | 17 | 60 HB | 45 % IACS |
As-quenched, stress relieved by stretching | Freshly quenched, refrigerated material used for stretch-forming or bending before artificial aging to T6/T73. | 220 | 380 | 17 | 95 HB | 31 % IACS |
Solution heat treated and overaged for stress-corrosion resistance | Choose where stress-corrosion cracking in the short-transverse direction must be eliminated, accepting ~10 % strength loss. | 420 | 490 | 13 | 133 HB | 40 % IACS |
T73, stress relieved by stretching | Default damage-tolerant plate temper: highest fracture toughness plus SCC immunity and low residual stress for heavy machining. | 421 | 490 | 13 | 135 HB | 40 % IACS |
Overaged for exfoliation resistance | Sheet temper balancing near-T6 strength with exfoliation/SCC resistance for skins and thin machined parts. | 427 | 496 | 12 | 136 HB | 38.5 % IACS |
T6 variant, underaged | Standard high-toughness 7475 sheet temper for fuselage/wing skins needing damage tolerance at near-T6 strength. | 448 | 524 | 12 | 142 HB | 36 % IACS |
Overaged for exfoliation-corrosion resistance | High-purity 7475 sheet/plate overaged to the T76 condition, trading a little strength from T6 for markedly better exfoliation-corrosion resistance and fracture toughness. | 455 | 524 | 12 | 142 HB | 40 % IACS |
T76, stress relieved by stretching | Plate compromise between T651 strength and T7351 corrosion/toughness; common for machined wing and frame components. | 455 | 524 | 12 | 140 HB | 38.5 % IACS |
Solution heat treated and artificially aged | Pick for maximum static strength where SCC exposure is low and part is not stretch-relieved. | 496 | 565 | 11 | 148 HB | 33 % IACS |
T6, stress relieved by stretching | Peak-strength plate with low residual stress for machined structural parts and moulds. | 496 | 565 | 11 | 150 HB | 33 % IACS |
What is 7475?
7475 is a high-purity Al-Zn-Mg-Cu aerospace alloy derived from 7075 with tightly controlled Fe and Si and optimised processing, which raises fracture toughness and resistance to fatigue crack growth while holding 7075-level strength. It is supplied mainly as plate and sheet for damage-tolerance-critical parts such as fuselage skins, lower wing panels and bulkheads, with T73/T76-type overaged tempers balancing stress-corrosion and exfoliation resistance. It is not fusion weldable in structure, bare material needs cladding or anodizing for corrosion protection, and cost is well above standard 7075. 7475 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 477°C (891 °F). 7475 has a yield strength of 421 MPa (61.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 89% of aluminum grades. Elongation at break is 13% and the elastic modulus is 71 GPa (10.3 Msi).
What is 7475 used for?
- Wing skins
- Fuselage skins
- Stringers
Advantages
- Tough — resists crack growth — 66 MPa·√m (60.1 ksi·√in), better than 100% of aluminum grades
- High strength — 421 MPa (61.1 ksi), better than 89% 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
- Ductile — tolerates forming and impact — 13%, better than 79% of aluminum grades
Limitations
- Difficult to weld — 18/100, worse than 94% of aluminum grades
7475 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
7475 has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 477°C (891 °F).
Mechanical12
7475 has a yield strength of 421 MPa (61.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 89% of aluminum grades. Elongation at break is 13% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
7475 is rated for continuous service to 150°C (302 °F). It conducts heat at 163 W/m·K (94.2 BTU/hr·ft·°F), better than 77% of aluminum grades. Thermal expansion is 22.7 µm/m·K (12.6 µin/in·°F).
Electrical3
7475 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (50/100), worse than 56% of aluminum grades.
Sustainability4
Producing a kilogram of 7475 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 12%.
Manufacturability8
7475's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (18/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 7475 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 7475
Is 7475 easy to machine?
Machines well in aged tempers with sharp polished-flute carbide, high speed and flood coolant; T7x plate distorts less than T651 thanks to stretch stress relief.
Can 7475 be welded?
Not fusion weldable in structure (hot cracking, SCC in HAZ) — join by riveting, adhesive bonding or friction-stir welding with post-weld temper control.
Can 7475 be formed, bent or molded?
Form in O or freshly quenched W temper then age; aged T6/T7x sheet needs generous bend radii (typically ≥4–6 t) and often warm forming.
Manufacturability
The process limits FabDigit applies to 7475. Every 7475 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Excellent72 / 100 |
|---|---|
| ISO material group | N.1 |
| Cutting speed (rough / finish) | 350 / 420 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 8× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Not Recommend30 / 100 |
|---|---|
| Weldability | Not Recommend18 / 100 |
7475 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 |
|---|---|---|
| Zn | 5.2 – 6.2 | 5.7 |
| Mg | 1.9 – 2.6 | 2.25 |
| Cu | 1.2 – 1.9 | 1.6 |
| Crgrain-structure control | 0.18 – 0.25 | 0.21 |
| Fetightly limited for toughness | ≤ 0.12 | 0.07 |
| Sitightly limited for toughness | ≤ 0.1 | 0.06 |
| Mn | ≤ 0.06 | 0.02 |
| Ti | ≤ 0.06 | 0.03 |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 7475?
Responds well to chromate/anodic pretreatments; clear or hard anodize is standard, and aerospace parts are usually clad, chromated and primed for corrosion protection.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Passivation
Conversion Coating
PVD Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 7475 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A97475
- Aluminum Association
- AA7475
- EN / DIN / Werkstoff-Nr.
- AW-7475AW 7475
How much does 7475 cost?
7475 is a premium-cost aluminum ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
7475 — frequently asked
What is 7475 used for?
7475 is typically used for wing skins, fuselage skins and stringers. In short: damage-tolerant aerospace plate.
What is the yield strength of 7475?
7475 has a typical yield strength of 421 MPa (61.1 ksi) and a tensile strength of 490 MPa (71.1 ksi) — stronger than 89% of aluminum grades. Strength varies by condition: see the 10 listed tempers.
Is 7475 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well in aged tempers with sharp polished-flute carbide, high speed and flood coolant; T7x plate distorts less than T651 thanks to stretch stress relief.
Can 7475 be welded?
Not readily — weldability is rated poor (18/100). Not fusion weldable in structure (hot cracking, SCC in HAZ) — join by riveting, adhesive bonding or friction-stir welding with post-weld temper control.
What surface finishes work on 7475?
Responds well to chromate/anodic pretreatments; clear or hard anodize is standard, and aerospace parts are usually clad, chromated and primed for corrosion protection.
Can 7475 be formed, bent or molded?
Form in O or freshly quenched W temper then age; aged T6/T7x sheet needs generous bend radii (typically ≥4–6 t) and often warm forming.
What is the maximum service temperature of 7475?
7475 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 7475 cost?
7475 is a premium-cost aluminum ($$$), cheaper than about 51% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 7475?
Yes — 7475 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. 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 4202 / AMS 4084 — 7475 Aluminum Alloy Plate and Sheet — SAE International (2019)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 19: Fatigue and Fracture — ASM International (1996)
- MMPDS-Metallic Materials Properties Development and Standardization (7475 typical values) — FAA/Battelle (2023)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.