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Aluminum 7003 vs 7A04

Aluminum · grade comparison

Aluminum 7003 and 7A04 are both aluminum grades. 7A04 is the stronger of the two: yield strength 475 MPa (68.9 ksi) against 315 MPa (45.7 ksi) for 7003, about 51% more; tensile strength follows at 545 MPa (79 ksi) vs 360 MPa (52.2 ksi). In exchange, 7003 is the more ductile: elongation 11% versus 8% for 7A04, and 7A04 is harder (150 HB vs 105 HB). 7003 conducts heat better (150 W/m·K vs 130 W/m·K). On the shop floor, 7003 welds better (very good vs poor) and 7003 sits in a lower cost tier (standard, $$) than 7A04 (premium, $$$).

7003Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

7A04Choose it when strength drives the design.

7003 vs 7A04: properties

70037A04

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70 GPa10.2 Msi
71 GPa10.3 Msi

Shear Modulus

26.5 GPa3.8 Msi
26.9 GPa3.9 Msi

Bulk Modulus

71 GPa10.3 Msi
69 GPa10 Msi

Tensile Strength (Ultimate)

360 MPa52.2 ksi
545 MPa79 ksi

Yield Strength (0.2% offset)

315 MPa45.7 ksi
475 MPa68.9 ksi

Elongation at Break

11%
8%

Compressive Strength

320 MPa46.4 ksi
490 MPa71.1 ksi

Shear Strength

210 MPa30.5 ksi
330 MPa47.9 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
160 MPa23.2 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
160 HV

Hardness, Rockwell B

—
87 HRB

Same in both: Poisson's Ratio 0.33

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
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
23.4 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
33 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
5.2×10⁻⁸ Ω·m2.05 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
72 / 100

Machinability Rating (AISI 1212 = 100 %)

200%
—

Weldability

75 / 100
20 / 100

Formability (cold)

35 / 100
25 / 100

Same in both: Brazeability / Solderability 15 / 100 · Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

205 MJ/kg88,134 BTU/lb
200 MJ/kg85,985 BTU/lb

Embodied Carbon (primary production)

12.5 kg CO₂/kg
14 kg CO₂/kg

Typical Recycled Content

30%
10%

Same in both: Embodied Water 1,200 L/kg144 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

129 kN·m/kg
191 kN·m/kg

Specific Stiffness (E / density)

25.2 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

709 kJ/m³
1,589 kJ/m³

Thermal Diffusivity

61.7 mm²/s
47.5 mm²/s

Thermal Shock Resistance Index

33
43

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 scale70037A04

Manufacturing and finishing

Capability70037A04
CNC machiningYes—
Sheet metalYes—
Default condition——
Relative cost$$ Standard$$$ Premium
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
Anodizing Type IIYes—
CerakoteYes—
Chem Film (Alodine)Yes—
DLCYes—
E-CoatingYes—
ElectropolishingYes—
Hard Anodize Type III w/ PTFEYes—
Hard Anodizing Type IIIYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—

They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

7003 vs 7A04 — frequently asked

Is 7A04 stronger than 7003?

Yes. 7A04 has a typical yield strength of 475 MPa (68.9 ksi) against 315 MPa (45.7 ksi) for 7003 — about 51% more. Tensile strength is 545 MPa (79 ksi) vs 360 MPa (52.2 ksi).

Which is cheaper, 7003 or 7A04?

7003 is the lower-cost material: it sits in the standard tier ($$) while 7A04 is premium ($$$). 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 7A04?

7A04. Its machinability rates very good (72/100) against good (65/100) for 7003; for welding the order is 7003 first (very good, 75/100) then 7A04 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7003 and 7A04 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.