Intent: Fatigue crack growth resistance and fracture toughness (tension applications) vs peak static compressive and tensile yield strength.
Engineering Verdict & When to Choose Each
2024 or 7075: specify the failure mode and evidence
By Mat Grades Editorial Desk · Updated 2026-11-14
Both alloys deserve a condition-specific review in demanding structural applications. Select by the relevant strength, fatigue, toughness and corrosion requirements rather than assuming that the highest tensile figure wins. The alloy number without temper, product form and direction is an incomplete design input.
For a thin load-carrying plate, establish the stress spectrum, notch details and inspection approach. Compare source evidence for the actual thickness and orientation. A small coupon result in a different condition is not sufficient support for a critical component.
Manufacturing can decide the practical route. Discuss material removal, residual-stress movement, fastening and surface protection with the supplier and machine shop. A prototype should include the final finish and the difficult geometry. Keep the approved source and condition with the design record so that a later substitution is reviewed against the evidence that justified the original selection.
2024 Aluminum: evidence to check
2024 Aluminum has 29 cataloged property rows. Modulus of Elasticity is reported as 73 GPa (typical; further condition not stated). Electrical Conductivity is reported as 50 % IACS (typical; O Temper). The record identifies ASTM B209 for Sheet & Plate; check its scope and ordered edition. These are source-scoped examples rather than unrestricted design allowables. Read the full row context and certificate before using a value for acceptance; an absent value is not zero or a performance failure.
7075 Aluminum: evidence to check
7075 Aluminum has 29 cataloged property rows. Modulus of Elasticity is reported as 72 GPa (typical; further condition not stated). Electrical Conductivity is reported as 45 % IACS (typical; O Temper). The record identifies ASTM B209 for Sheet & Plate; check its scope and ordered edition. These are source-scoped examples rather than unrestricted design allowables. Read the full row context and certificate before using a value for acceptance; an absent value is not zero or a performance failure.
Four questions before approval
- Which failure mode and load spectrum control the part?
- Are temper, thickness and direction comparable?
- Is the required fatigue or toughness evidence available?
- Does the trial include the final protective finish?
Check the linked material records for the complete source trail. Read the methodology before comparing minimum requirements with typical measurements. No direct substitution or qualified fabrication procedure is implied.
Material Comparison
Compare verified engineering materials side by side with condition-specific mechanical properties.
| Parameter | 2024 Aluminum | 7075 Aluminum |
|---|---|---|
| Material Family | Aluminum & Aluminum Alloys | Aluminum & Aluminum Alloys |
| Subfamily | Wrought Aluminum Alloys | Wrought Aluminum Alloys |
| AA Designation | 2024 | 7075 |
| UNS Designation | A92024 | A97075 |
| ISO Designation | AlCu4Mg1 | AlZn5.5MgCu |
| Element | 2024 Aluminum | 7075 Aluminum |
|---|---|---|
| Si (Silicon) | ≤ 0.5% | ≤ 0.4% |
| Fe (Iron) | ≤ 0.5% | ≤ 0.5% |
| Cu (Copper) | 3.8 – 4.9% | 1.2 – 2% |
| Mn (Manganese) | 0.3 – 0.9% | ≤ 0.3% |
| Mg (Magnesium) | 1.2 – 1.8% | 2.1 – 2.9% |
| Cr (Chromium) | ≤ 0.1% | 0.18 – 0.28% |
| Zn (Zinc) | ≤ 0.25% | 5.1 – 6.1% |
| Ti (Titanium) | ≤ 0.15% | ≤ 0.2% |
| OE (Other Elements Each) | OE: ≤ 0.05% each | OE: ≤ 0.05% each |
| OT (Other Elements Total) | ≤ 0.15% | ≤ 0.15% |
| Al (Aluminum) | — | — |
| Property | 2024 Aluminum | 7075 Aluminum |
|---|---|---|
| Density · TYPICALUnit: g/cm³ | 2.77 g/cm³ | 2.8 g/cm³ |
| Mechanical Parameter | 2024 AluminumO | 7075 AluminumO |
|---|---|---|
| Modulus of Elasticity · TYPICALUnit: GPa | 73 GPa | 72 GPa |
| Ultimate Tensile Strength · Cold Finished Rod & Bar · O Temper · TYPICALUnit: MPa | 186 MPa | 228 MPa |
| Yield Strength (0.2% Offset) · Cold Finished Rod & Bar · O Temper · TYPICALUnit: MPa | 76 MPa | 103 MPa |
| Elongation (4D) · Cold Finished Rod & Bar · O Temper · TYPICALUnit: % | 20 % | 17 % |
| Shear Strength · Cold Finished Rod & Bar · O Temper · TYPICALUnit: MPa | 124 MPa | 152 MPa |
| Fatigue Endurance Limit (5x10^8 cycles) · Cold Finished Rod & Bar · O Temper · TYPICALUnit: MPa | 90 MPa | 117 MPa |
| Property | 2024 Aluminum | 7075 Aluminum |
|---|---|---|
| Electrical Conductivity · O Temper · TYPICALCategory: ELECTRICAL • Unit: % IACS | 50 % IACS | 45 % IACS |
| Coefficient of Thermal Expansion · TYPICALCategory: THERMAL • Unit: µm/(m·K) | 23.2 µm/(m·K) | 23.4 µm/(m·K) |
| Solidus Temperature · TYPICALCategory: THERMAL • Unit: °C | 502 °C | 532 °C |
| Liquidus Temperature · TYPICALCategory: THERMAL • Unit: °C | 638 °C | 635 °C |
| Thermal Conductivity · O Temper · TYPICALCategory: THERMAL • Unit: W/(m·K) | 190 W/(m·K) | 173 W/(m·K) |
| Hardness Scale | 2024 Aluminum | 7075 Aluminum |
|---|---|---|
| HB Hardness · Cold Finished Rod & Bar · O Temper · TYPICAL | 47 HB | 60 HB |