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Aluminum 7003 vs 7075

Aluminum · grade comparison

Aluminum 7003 and 7075 are both aluminum grades, both high strength al. 7075 is the stronger of the two: yield strength 503 MPa (73 ksi) against 315 MPa (45.7 ksi) for 7003, about 60% more; tensile strength follows at 572 MPa (83 ksi) vs 360 MPa (52.2 ksi). 7075 is harder — 150 HB against 105 HB for 7003 — which matters for wear surfaces and threads. 7003 conducts heat better (150 W/m·K vs 130 W/m·K). On the shop floor, 7075 machines more easily (very good vs good), 7003 welds better (very good vs poor), and 7003 forms better (fair vs poor).

7003Choose it when it will be welded, or when cost is the deciding factor.

7075Choose it when strength drives the design, or when surface hardness matters.

7003 vs 7075: properties

70037075

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70 GPa10.2 Msi
71.7 GPa10.4 Msi

Shear Modulus

26.5 GPa3.8 Msi
26.9 GPa3.9 Msi

Bulk Modulus

71 GPa10.3 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

360 MPa52.2 ksi
572 MPa83 ksi

Yield Strength (0.2% offset)

315 MPa45.7 ksi
503 MPa73 ksi

Compressive Strength

320 MPa46.4 ksi
505 MPa73.2 ksi

Shear Strength

210 MPa30.5 ksi
331 MPa48 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
159 MPa23.1 ksi

Fracture Toughness (K_IC)

28 MPa·√m25.5 ksi·√in
27 MPa·√m24.6 ksi·√in

Hardness, Brinell

105 HB
150 HB

Hardness, Vickers

112 HV
175 HV

Reduction in Area

—
25%

Charpy V-Notch Impact (RT)

—
8 J5.9 ft·lbf

Hardness, Rockwell B

—
87 HRB

Same in both: Poisson's Ratio 0.33 · Elongation at Break 11%

Physical

Density and transition temperatures.

Density

2.78 g/cm³0.1 lb/in³
2.81 g/cm³0.1 lb/in³

Melting Point (Solidus)

605°C1,121 °F
477°C891 °F

Liquidus Temperature

645°C1,193 °F
635°C1,175 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

150 W/m·K86.7 BTU/hr·ft·°F
130 W/m·K75.1 BTU/hr·ft·°F

Specific Heat Capacity

875 J/kg·K0.21 BTU/lb·°F
960 J/kg·K0.23 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

23.2 µm/m·K12.9 µin/in·°F
23.6 µm/m·K13.1 µin/in·°F

Latent Heat of Fusion

390 J/g168 BTU/lb
395 J/g170 BTU/lb

Same in both: Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

39 % IACS
33 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
5.15×10⁻⁸ Ω·m2.03 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.86 V
-0.83 V

Corrosion Resistance

55 / 100
35 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

65 / 100
78 / 100

Machinability Rating (AISI 1212 = 100 %)

200%
160%

Weldability

75 / 100
18 / 100

Formability (cold)

35 / 100
25 / 100

Brazeability / Solderability

15 / 100
10 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

30%
15%

Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

129 kN·m/kg
204 kN·m/kg

Specific Stiffness (E / density)

25.2 MN·m/kg
25.5 MN·m/kg

Modulus of Resilience

709 kJ/m³
1,764 kJ/m³

Thermal Diffusivity

61.7 mm²/s
48.2 mm²/s

Thermal Shock Resistance Index

33
44

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.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scale70037075

Manufacturing and finishing

Capability70037075
Default condition—T6
Relative cost$$ Standard$$$ Premium
Min. machined wall0.5 mm0.8 mm
Best machined surfaceRa 0.8 µmRa 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.

7003 vs 7075 — frequently asked

Is 7075 stronger than 7003?

Yes. 7075 has a typical yield strength of 503 MPa (73 ksi) against 315 MPa (45.7 ksi) for 7003 — about 60% more. Tensile strength is 572 MPa (83 ksi) vs 360 MPa (52.2 ksi).

Which is cheaper, 7003 or 7075?

7003 is the lower-cost material: it sits in the standard tier ($$) while 7075 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 7003 or 7075?

7075. Its machinability rates very good (78/100) against good (65/100) for 7003; for welding the order is 7003 first (very good, 75/100) then 7075 (poor, 18/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7003 and 7075 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.