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Aluminum 7003 vs 7A85

Aluminum · grade comparison

Aluminum 7003 and 7A85 are both aluminum grades. 7A85 is the stronger of the two: yield strength 470 MPa (68.2 ksi) against 315 MPa (45.7 ksi) for 7003, about 49% more; tensile strength follows at 510 MPa (74 ksi) vs 360 MPa (52.2 ksi). 7A85 is harder — 155 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, $$) than 7A85 (high, $$$$).

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

7A85Choose it when strength drives the design, or when surface hardness matters.

7003 vs 7A85: properties

70037A85

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
75 GPa10.9 Msi

Tensile Strength (Ultimate)

360 MPa52.2 ksi
510 MPa74 ksi

Yield Strength (0.2% offset)

315 MPa45.7 ksi
470 MPa68.2 ksi

Elongation at Break

11%
10%

Compressive Strength

320 MPa46.4 ksi
480 MPa69.6 ksi

Shear Strength

210 MPa30.5 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
160 MPa23.2 ksi

Fracture Toughness (K_IC)

28 MPa·√m25.5 ksi·√in
40 MPa·√m36.4 ksi·√in

Hardness, Brinell

105 HB
155 HB

Hardness, Vickers

112 HV
165 HV

Reduction in Area

—
22%

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
476°C889 °F

Liquidus Temperature

645°C1,193 °F
635°C1,175 °F

Thermal

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

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
23.6 µm/m·K13.1 µin/in·°F

Same in both: Thermal Conductivity 150 W/m·K86.7 BTU/hr·ft·°F · 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
40 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
4.3×10⁻⁸ Ω·m1.69 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.86 V
-0.82 V

Corrosion Resistance

55 / 100
48 / 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%
190%

Weldability

75 / 100
20 / 100

Formability (cold)

35 / 100
25 / 100

Brazeability / Solderability

15 / 100
10 / 100

Castability

—
30 / 100

Same in both: Polishability 60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

205 MJ/kg88,134 BTU/lb
210 MJ/kg90,284 BTU/lb

Embodied Carbon (primary production)

12.5 kg CO₂/kg
13 kg CO₂/kg

Embodied Water

1,200 L/kg144 gal/lb
1,100 L/kg132 gal/lb

Typical Recycled Content

30%
5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

129 kN·m/kg
179 kN·m/kg

Specific Stiffness (E / density)

25.2 MN·m/kg
24.9 MN·m/kg

Modulus of Resilience

709 kJ/m³
1,556 kJ/m³

Thermal Diffusivity

61.7 mm²/s
61.2 mm²/s

Thermal Shock Resistance Index

33
46

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 scale70037A85

Manufacturing and finishing

Capability70037A85
CNC machiningYes—
Sheet metalYes—
Default condition——
Relative cost$$ Standard$$$$ High
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 7A85 — frequently asked

Is 7A85 stronger than 7003?

Yes. 7A85 has a typical yield strength of 470 MPa (68.2 ksi) against 315 MPa (45.7 ksi) for 7003 — about 49% more. Tensile strength is 510 MPa (74 ksi) vs 360 MPa (52.2 ksi).

Which is cheaper, 7003 or 7A85?

7003 is the lower-cost material: it sits in the standard tier ($$) while 7A85 is high ($$$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 7003 or 7A85?

7A85. 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 7A85 (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7003 and 7A85 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.