Aluminum 7A09-T7351
Temper
GB 7A09
T7351 = t73, stress relieved by stretching
Thick plate for machined airframe fittings needing both low residual stress and SCC immunity.
Values for the T7351 condition
Other 7A09 tempers and conditions
7A09 is listed in 10 conditions; see the grade overview at 7A09.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for deep forming, straightening or machining before heat treatment; must be re-solution treated and aged for service. | 105 | 230 | 16 | 60 HB | 47 % IACS |
T7351This page T73, stress relieved by stretching | Thick plate for machined airframe fittings needing both low residual stress and SCC immunity. | 420 | 490 | 12 | 130 HB | 40 % IACS |
Solution heat treated and overaged for stress-corrosion resistance | Pick for short-transverse loaded forgings and fasteners in humid/marine service where SCC must be eliminated, accepting ~10% lower strength. | 435 | 505 | 11 | 135 HB | 40 % IACS |
T74, stress relieved by stretching | Thick plate version of T74 for machined spars/bulkheads balancing strength, toughness and SCC resistance. | 445 | 515 | 11 | 137 HB | 38 % IACS |
Overaged between T73 and T76 | Compromise temper for heavy forgings: most of the T73 SCC benefit with higher strength than T73. | 455 | 525 | 10 | 140 HB | 38 % IACS |
T76, stress relieved by stretching | Stress-relieved T76 for machined thin-web panels needing exfoliation resistance and dimensional stability. | 460 | 525 | 10 | 140 HB | 38 % IACS |
T6, heat treated by the user | Choose when parts are formed/forged soft and heat treated after machining; properties slightly below mill T6. | 470 | 545 | 7 | 145 HB | 33 % IACS |
Overaged for exfoliation-corrosion resistance | Sheet/extrusion temper for thin skins and stringers where exfoliation resistance is required but T73 strength loss is unacceptable. | 470 | 535 | 9 | 142 HB | 38 % IACS |
T6, stress relieved by stretching | Plate temper for thick machined structures where low residual stress and dimensional stability matter. | 495 | 560 | 9 | 148 HB | 33 % IACS |
T6Default Solution heat treated and artificially aged | Default stocked condition: maximum strength for bar, extrusion and forging where SCC exposure is controlled. | 505 | 570 | 8 | 150 HB | 33 % IACS |
What is 7A09-T7351?
7A09-T7351 is 7A09 in the T7351 temper — thick plate for machined airframe fittings needing both low residual stress and SCC immunity. 7A09-T7351 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 12% and the elastic modulus is 71 GPa (10.3 Msi). 7A09-T7351 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 477°C (891 °F). T6 is the default condition FabDigit quotes; T7351 is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 35 MPa·√m (31.9 ksi·√in), better than 91% of aluminum grades
- High strength — 420 MPa (60.9 ksi), better than 89% of aluminum grades
Limitations
- Difficult to weld — 18/100, worse than 94% of aluminum grades
7A09-T7351 properties
Typical room-temperature values for 7A09-T7351; 21 are specific to this condition. Other listed values are 7A09 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
7A09-T7351 has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 477°C (891 °F).
Mechanical15
7A09-T7351 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 12% and the elastic modulus is 71 GPa (10.3 Msi).
Thermal6
7A09-T7351 is rated for continuous service to 150°C (302 °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
7A09-T7351 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (54/100), worse than 55% of aluminum grades.
Sustainability4
Producing a kilogram of 7A09-T7351 takes about 210 MJ of energy and emits 12.5 kg of CO₂ — more than 88% of aluminum grades. Typical recycled content is 15%.
Manufacturability8
7A09-T7351's machinability is very good (70/100, better than 72% of aluminum grades); weldability poor (18/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 7A09-T7351
Is 7A09 easy to machine?
Excellent chip formation in T6/T73; use sharp carbide, high speed and flood coolant, and rough from stress-relieved (T651/T7351) stock to avoid distortion.
Can 7A09 be welded?
Not arc-weldable (hot cracking, severe HAZ SCC); join by fasteners, bonding or friction stir welding, and re-heat-treat if welded.
Can 7A09 be formed, bent or molded?
Form in O or freshly quenched W temper; hot forge/extrude at ~380–450 °C, then solution treat 465–475 °C, water quench and age (T6: ~120 °C; T73/T74: two-step overage).
What surface finishes work on 7A09?
Chromate/trivalent conversion coat or Type II/III anodize for corrosion protection; anodic film is grey-bronze, so decorative bright anodizing is not recommended.
7A09 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 | 5.1 – 6.1 | 5.6 |
| Mg | 2 – 3 | 2.5 |
| Cu | 1.2 – 2 | 1.6 |
| Crgrain-boundary control / SCC resistance | 0.16 – 0.3 | 0.22 |
| Mn | ≤ 0.15 | — |
| Feimpurity | ≤ 0.5 | — |
| Siimpurity | ≤ 0.5 | — |
| Ti | ≤ 0.1 | — |
| Other (each)total 0.15 max | ≤ 0.05 | — |
| Al | balance | — |
7A09-T7351 — frequently asked
What is 7A09-T7351 used for?
7A09-T7351 is typically used for aircraft structural parts, high-strength forgings and machined structural components. In short: highest-strength 7000-series grade; 7178-equivalent property level; low ductility, not weldable.
What is the yield strength of 7A09-T7351?
7A09-T7351 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 7A09-T7351 easy to machine?
Yes — machinability is rated very good (70/100, better than 72% of aluminum grades). Excellent chip formation in T6/T73; use sharp carbide, high speed and flood coolant, and rough from stress-relieved (T651/T7351) stock to avoid distortion.
Can 7A09-T7351 be welded?
Not readily — weldability is rated poor (18/100). Not arc-weldable (hot cracking, severe HAZ SCC); join by fasteners, bonding or friction stir welding, and re-heat-treat if welded.
What surface finishes work on 7A09-T7351?
Chromate/trivalent conversion coat or Type II/III anodize for corrosion protection; anodic film is grey-bronze, so decorative bright anodizing is not recommended.
Can 7A09-T7351 be formed, bent or molded?
Form in O or freshly quenched W temper; hot forge/extrude at ~380–450 °C, then solution treat 465–475 °C, water quench and age (T6: ~120 °C; T73/T74: two-step overage).
What is the maximum service temperature of 7A09-T7351?
7A09-T7351 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.
What is the difference between 7A09-T6 and 7A09-O?
T6 is the default condition — default stocked condition: maximum strength for bar, extrusion and forging where SCC exposure is controlled. O: softest condition for deep forming, straightening or machining before heat treatment; must be re-solution treated and aged for service. Yield strength is 505 MPa in T6 versus 105 MPa in O.
Sources
- ASM Handbook Vol. 2 — Properties of Nonferrous Alloys (7075/7178 data) — ASM International (1990)
- MMPDS-16 typical/design values for 7000-series wrought products — Battelle/FAA (2021)
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.