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Aluminum 7003 vs 7055

Aluminum · grade comparison

Aluminum 7003 and 7055 are both aluminum grades. 7055 is the stronger of the two: yield strength 634 MPa (92 ksi) against 315 MPa (45.7 ksi) for 7003, about 101% more; tensile strength follows at 655 MPa (95 ksi) vs 360 MPa (52.2 ksi). 7055 is harder — 190 HB against 105 HB for 7003 — which matters for wear surfaces and threads. On the shop floor, 7003 welds better (very good vs poor), 7003 forms better (fair vs poor), and 7003 sits in a lower cost tier (standard, $$) than 7055 (high, $$$$).

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

7055Choose it when strength drives the design, or when surface hardness matters.

7003 vs 7055: properties

70037055

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70 GPa10.2 Msi
70.5 GPa10.2 Msi

Shear Modulus

26.5 GPa3.8 Msi
26.9 GPa3.9 Msi

Bulk Modulus

71 GPa10.3 Msi
75 GPa10.9 Msi

Tensile Strength (Ultimate)

360 MPa52.2 ksi
655 MPa95 ksi

Yield Strength (0.2% offset)

315 MPa45.7 ksi
634 MPa92 ksi

Compressive Strength

320 MPa46.4 ksi
648 MPa94 ksi

Shear Strength

210 MPa30.5 ksi
372 MPa54 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
185 MPa26.8 ksi

Fracture Toughness (K_IC)

28 MPa·√m25.5 ksi·√in
31 MPa·√m28.2 ksi·√in

Hardness, Brinell

105 HB
190 HB

Hardness, Vickers

112 HV
200 HV

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
2.85 g/cm³0.1 lb/in³

Melting Point (Solidus)

605°C1,121 °F
475°C887 °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
154 W/m·K89 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

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

Same in both: Latent Heat of Fusion 390 J/g168 BTU/lb · Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

39 % IACS
37 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
4.66×10⁻⁸ Ω·m1.83 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.86 V
-0.84 V

Corrosion Resistance

55 / 100
42 / 100

Manufacturability

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

Machinability

65 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

200%
70%

Weldability

75 / 100
15 / 100

Formability (cold)

35 / 100
20 / 100

Brazeability / Solderability

15 / 100
10 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

1,200 L/kg144 gal/lb
1,150 L/kg138 gal/lb

Typical Recycled Content

30%
12%

Same in both: Embodied Energy (primary production) 205 MJ/kg88,134 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

129 kN·m/kg
230 kN·m/kg

Specific Stiffness (E / density)

25.2 MN·m/kg
24.7 MN·m/kg

Modulus of Resilience

709 kJ/m³
2,851 kJ/m³

Thermal Diffusivity

61.7 mm²/s
62.8 mm²/s

Thermal Shock Resistance Index

33
61

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 scale70037055

Manufacturing and finishing

Capability70037055
Default condition——
Relative cost$$ Standard$$$$ High
Min. machined wall0.5 mm0.5 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 7055 — frequently asked

Is 7055 stronger than 7003?

Yes. 7055 has a typical yield strength of 634 MPa (92 ksi) against 315 MPa (45.7 ksi) for 7003 — about 101% more. Tensile strength is 655 MPa (95 ksi) vs 360 MPa (52.2 ksi).

Which is cheaper, 7003 or 7055?

7003 is the lower-cost material: it sits in the standard tier ($$) while 7055 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 7003 or 7055?

7003. Its weldability rates very good (75/100) against poor (15/100) for 7055.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7003 and 7055 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.