Aluminum 7175
AA 7175 · EN AW-7175, AW 7175
7175 is a high-purity (low Fe, Si) version of 7075 in the heat-treatable Al–Zn–Mg–Cu system, supplied mainly as aerospace die forgings, open-die forgings and thick plate.
7175 tempers and conditions
7175 is supplied in 13 conditions, soft to hard.
Compare all 13 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, used only for intermediate forming/machining before solution treatment. | 105 | 230 | 17 | 60 HB | 45 % IACS |
T73, stress relieved by stretching | Low-residual-stress overaged plate/bar for thick machined aerospace fittings. | 440 | 510 | 12 | 138 HB | 40 % IACS |
Overaged, stress relieved by cold compression | Large forgings that must be heavily machined — compression stress relief keeps parts dimensionally stable. | 440 | 510 | 10 | 142 HB | 39 % IACS |
Extrusion: overaged, stretched, minor straightening permitted | Overaged extruded shapes/bar where SCC resistance and straightness are both required. | 450 | 515 | 10 | 140 HB | 40 % IACS |
Solution treated, stress relieved by stretching/compression, overaged | Default aerospace supply condition: overaged for SCC resistance with residual stress removed for dimensionally stable machining. | 455 | 524 | 11 | 140 HB | 40 % IACS |
Overaged (T74) and stress relieved by cold restriking in the finish die | High-strength Al-Zn-Mg-Cu die-forging temper: T74 two-step overage giving near-T6 strength with good SCC and exfoliation resistance, residual stress removed by cold restrike in the finish die. | 455 | 525 | 11 | 135 HB | 40 % IACS |
Solution heat treated and overaged for stress-corrosion resistance | Choose when short-transverse SCC resistance and toughness outrank peak strength. | 455 | 525 | 12 | 140 HB | 40 % IACS |
Overaged between T73 and T76 | The workhorse 7175 forging temper: near-T6 strength with T73-level SCC and toughness performance. | 455 | 524 | 11 | 145 HB | 39 % IACS |
Extrusion: T74 overaged, stretched, straightened | Extruded stringers/spar caps needing higher strength than T73511 with good SCC behaviour. | 490 | 545 | 10 | 148 HB | 38 % IACS |
Extrusion: overaged for exfoliation resistance, stretched | Intermediate overage giving good exfoliation resistance with strength above T73 tempers. | 490 | 545 | 10 | 148 HB | 38 % IACS |
T6, stress relieved by stretching | Peak-strength plate with low residual stress for stable machining of thick parts. | 515 | 585 | 11 | 150 HB | 33 % IACS |
Solution heat treated and artificially aged | Maximum strength condition for forgings/extrusions where SCC exposure is low. | 525 | 595 | 11 | 150 HB | 33 % IACS |
T6 with improved mechanical properties | Highest-strength registered temper for 7175 die forgings when maximum static strength is needed. | 560 | 620 | 9 | 160 HB | 32 % IACS |
What is 7175?
7175 is a high-purity (low Fe, Si) version of 7075 in the heat-treatable Al–Zn–Mg–Cu system, supplied mainly as aerospace die forgings, open-die forgings and thick plate. Fewer inclusions and a controlled grain structure give higher fracture toughness and more uniform short-transverse properties than 7075 at the same strength level, which suits fuselage frames, landing gear parts and fittings. It is essentially not arc weldable, is stress-corrosion sensitive unless used in overaged T73/T74-type tempers, costs more than 7075 and has limited cold formability. 7175 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). 7175 has a yield strength of 455 MPa (66 ksi) and a tensile strength of 524 MPa (76 ksi) — stronger than 92% of aluminum grades. Elongation at break is 11% and the elastic modulus is 71.7 GPa (10.4 Msi).
What is 7175 used for?
- Aircraft structural fittings
- Helicopter rotor hubs
- Fuselage frames and bulkheads
- Landing gear components
- Wing and spar forgings
- Highly loaded machined brackets
- Thick-plate structural parts
Advantages
- High strength — 455 MPa (66 ksi), better than 92% of aluminum grades
- Easy to machine — 78/100, better than 89% of aluminum grades
- Tough — resists crack growth — 33 MPa·√m (30 ksi·√in), better than 87% of aluminum grades
Limitations
- Difficult to weld — 12/100, worse than 98% of aluminum grades
7175 properties
Typical room-temperature values; bars are the position among aluminum grades.
Physical3
7175 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).
Mechanical14
7175 has a yield strength of 455 MPa (66 ksi) and a tensile strength of 524 MPa (76 ksi) — stronger than 92% of aluminum grades. Elongation at break is 11% and the elastic modulus is 71.7 GPa (10.4 Msi).
Thermal6
7175 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
7175 conducts electricity at 40 % IACS, better than 72% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.
Sustainability4
Producing a kilogram of 7175 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 8%.
Manufacturability7
7175's machinability is very good (78/100, better than 89% of aluminum grades); weldability not recommended (12/100); 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.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 7175 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 7175
Is 7175 easy to machine?
Machines very well in T7x tempers with sharp polished carbide, high speed and flood coolant; expect long chips and use chip-breaking geometry.
Can 7175 be welded?
Not arc weldable for structure (hot-cracking, SCC in HAZ); join by riveting, bolting, adhesive bonding or friction stir welding with process qualification.
Can 7175 be formed, bent or molded?
Forge/hot work at ~380–440 °C; cold forming in T-tempers is very limited — form in O or W temper and re-heat-treat.
Manufacturability
The process limits FabDigit applies to 7175. Every 7175 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Excellent78 / 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 Recommend25 / 100 |
|---|---|
| Weldability | Not Recommend12 / 100 |
7175 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 | 2.1 – 2.9 | 2.5 |
| Cu | 1.2 – 2 | 1.6 |
| Crgrain-structure control | 0.18 – 0.28 | 0.23 |
| Ferestricted vs 7075 for toughness | ≤ 0.2 | 0.12 |
| Sirestricted vs 7075 | ≤ 0.15 | 0.08 |
| Mn | ≤ 0.1 | 0.03 |
| Ti | ≤ 0.1 | 0.03 |
| Others (each) | ≤ 0.05 | |
| Others (total) | ≤ 0.15 | |
| Al | balance |
What surface finishes work on 7175?
Chromic/sulfuric anodize, Type III hardcoat, chemical conversion coating (Alodine) plus primer; avoid caustic etch overexposure on close-tolerance machined parts.
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 7175 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Aluminum Association
- AA7175
- EN / DIN / Werkstoff-Nr.
- AW-7175AW 71753.4334
How much does 7175 cost?
7175 is a premium-cost aluminum ($$$), cheaper than about 58% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
7175 — frequently asked
What is 7175 used for?
7175 is typically used for aircraft structural fittings, helicopter rotor hubs, fuselage frames and bulkheads, landing gear components, wing and spar forgings and highly loaded machined brackets. In short: premium aerospace forging.
What is the yield strength of 7175?
7175 has a typical yield strength of 455 MPa (66 ksi) and a tensile strength of 524 MPa (76 ksi) — stronger than 92% of aluminum grades. Strength varies by condition: see the 13 listed tempers.
Is 7175 easy to machine?
Yes — machinability is rated very good (78/100, better than 89% of aluminum grades). Machines very well in T7x tempers with sharp polished carbide, high speed and flood coolant; expect long chips and use chip-breaking geometry.
Can 7175 be welded?
Not readily — weldability is rated not recommended (12/100). Not arc weldable for structure (hot-cracking, SCC in HAZ); join by riveting, bolting, adhesive bonding or friction stir welding with process qualification.
What surface finishes work on 7175?
Chromic/sulfuric anodize, Type III hardcoat, chemical conversion coating (Alodine) plus primer; avoid caustic etch overexposure on close-tolerance machined parts.
Can 7175 be formed, bent or molded?
Forge/hot work at ~380–440 °C; cold forming in T-tempers is very limited — form in O or W temper and re-heat-treat.
What is the maximum service temperature of 7175?
7175 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 7175 cost?
7175 is a premium-cost aluminum ($$$), cheaper than about 58% 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 7175?
Yes — 7175 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 4149 — Aluminum Alloy 7175 Die Forgings and Rolled Rings, T74 — SAE International (2018)
- ASTM B247 — Aluminum-Alloy Die, Hand and Rolled Ring Forgings — ASTM International (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- MMPDS — Metallic Materials Properties Development and Standardization — Battelle/FAA (2019)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.