Aluminum 7475 · temper
Aluminum 7475-T73
Properties of the T73 condition, compared with the other 7475 tempers.
Choose where stress-corrosion cracking in the short-transverse direction must be eliminated, accepting ~10 % strength loss.
What is 7475-T73?
7475-T73 is 7475 in the T73 temper — choose where stress-corrosion cracking in the short-transverse direction must be eliminated, accepting ~10 % strength loss. 7475-T73 has a yield strength of 420 MPa (60.9 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). 7475-T73 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).
Advantages
- Tough — resists crack growth — 68 MPa·√m (61.9 ksi·√in), better than 100% of aluminum grades
- High strength — 420 MPa (60.9 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-T73 properties
Typical room-temperature values for 7475-T73 — 11 properties are specific to this condition; the rest are grade-level values shared by every 7475 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
7475-T73 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-T73 has a yield strength of 420 MPa (60.9 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-T73 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-T73 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), worse than 55% of aluminum grades.
Sustainability4
Producing a kilogram of 7475-T73 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 75% of aluminum grades. Typical recycled content is 12%.
Manufacturability8
7475-T73's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (18/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 7475 tempers and conditions
7475 is also supplied in 9 other conditions. The full side-by-side table is on the 7475 overview.
- T6Pick for maximum static strength where SCC exposure is low and part is not stretch-relieved.496 MPa yield · 148 HB
- T651Peak-strength plate with low residual stress for machined structural parts and moulds.496 MPa yield · 150 HB
- T76High-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 MPa yield · 142 HB
- T7651Plate compromise between T651 strength and T7351 corrosion/toughness; common for machined wing and frame components.455 MPa yield · 140 HB
- T61Standard high-toughness 7475 sheet temper for fuselage/wing skins needing damage tolerance at near-T6 strength.448 MPa yield · 142 HB
- T761Sheet temper balancing near-T6 strength with exfoliation/SCC resistance for skins and thin machined parts.427 MPa yield · 136 HB
- T7351Default damage-tolerant plate temper: highest fracture toughness plus SCC immunity and low residual stress for heavy machining.421 MPa yield · 135 HB
- T73Choose where stress-corrosion cracking in the short-transverse direction must be eliminated, accepting ~10 % strength loss.420 MPa yield · 133 HB
- OSoftest condition for severe forming or machining before solution treatment.105 MPa yield · 60 HB
Working with 7475-T73
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.
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.
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 | — |
7475-T73 — frequently asked
What is 7475-T73 used for?
7475-T73 is typically used for wing skins, fuselage skins and stringers. In short: damage-tolerant aerospace plate.
What is the yield strength of 7475-T73?
7475-T73 has a typical yield strength of 420 MPa (60.9 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-T73 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-T73 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-T73?
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-T73 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-T73?
7475-T73 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 7475-T73?
Yes — 7475-T73 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 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.