Aluminum 7075 vs 7178
Aluminum · grade comparison
Aluminum 7075 and 7178 are both aluminum grades. 7178 is the stronger of the two: yield strength 538 MPa (78 ksi) against 503 MPa (73 ksi) for 7075, about 7% more; tensile strength follows at 607 MPa (88 ksi) vs 572 MPa (83 ksi). 7178 is harder — 160 HB against 150 HB for 7075 — which matters for wear surfaces and threads.
7178Choose it when strength drives the design, or when surface hardness matters.
7075 vs 7178: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Reduction in Area
Compressive Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Hardness, Rockwell B
Same in both: Elastic (Young's) Modulus 71.7 GPa10.4 Msi · Shear Modulus 26.9 GPa3.9 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Shear Strength 331 MPa48 ksi · Hardness, Vickers 175 HV
Physical
Density and transition temperatures.
Density
Liquidus Temperature
Same in both: Melting Point (Solidus) 477°C891 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Same in both: Brazeability / Solderability 10 / 100 · Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Water
Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Typical Recycled Content 15%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Strength versus weight
Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | 7075 | 7178 |
|---|---|---|
| Default condition | T6 | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 0.8 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining and Sheet metal. Both take the same 16 finishes: Anodizing Type II, Cerakote, Chem Film (Alodine), DLC, E-Coating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Nickel Plating and 4 more.
7075 vs 7178 — frequently asked
Is 7178 stronger than 7075?
Yes. 7178 has a typical yield strength of 538 MPa (78 ksi) against 503 MPa (73 ksi) for 7075 — about 7% more. Tensile strength is 607 MPa (88 ksi) vs 572 MPa (83 ksi).
Which is cheaper, 7075 or 7178?
Both sit in the same relative cost tier ($$$, premium); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, 7075 or 7178?
7075, by a small margin. Both rate very good for machinability — 78/100 against 72/100 for 7178; for welding the order is 7075 first (poor, 18/100) then 7178 (not recommended, 12/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 7075 and 7178 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.