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Aluminum 7003 vs 7129

Aluminum · grade comparison

Aluminum 7003 and 7129 are both aluminum grades. 7129 is the stronger of the two: yield strength 350 MPa (50.8 ksi) against 315 MPa (45.7 ksi) for 7003, about 11% more; tensile strength follows at 400 MPa (58 ksi) vs 360 MPa (52.2 ksi). 7129 is harder — 120 HB against 105 HB for 7003 — which matters for wear surfaces and threads. 7003 conducts electricity better (39 % IACS vs 32 % IACS). On the shop floor, 7003 welds better (very good vs poor) and 7003 sits in a lower cost tier (standard, $$) than 7129 (premium, $$$).

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

7129Choose it when strength drives the design, or when surface hardness matters.

7003 vs 7129: properties

70037129

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

71 GPa10.3 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

360 MPa52.2 ksi
400 MPa58 ksi

Yield Strength (0.2% offset)

315 MPa45.7 ksi
350 MPa50.8 ksi

Compressive Strength

320 MPa46.4 ksi
355 MPa51.5 ksi

Shear Strength

210 MPa30.5 ksi
235 MPa34.1 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
150 MPa21.8 ksi

Fracture Toughness (K_IC)

28 MPa·√m25.5 ksi·√in
30 MPa·√m27.3 ksi·√in

Hardness, Brinell

105 HB
120 HB

Hardness, Vickers

112 HV
130 HV

Same in both: Elastic (Young's) Modulus 70 GPa10.2 Msi · Shear Modulus 26.5 GPa3.8 Msi · Poisson's Ratio 0.33 · Elongation at Break 11%

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

605°C1,121 °F
480°C896 °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
155 W/m·K89.6 BTU/hr·ft·°F

Specific Heat Capacity

875 J/kg·K0.21 BTU/lb·°F
865 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
32 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
5.4×10⁻⁸ Ω·m2.13 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
40 / 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
30 / 100

Same in both: Formability (cold) 35 / 100 · Brazeability / Solderability 15 / 100 · Polishability 60 / 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%
25%

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
143 kN·m/kg

Specific Stiffness (E / density)

25.2 MN·m/kg
25 MN·m/kg

Modulus of Resilience

709 kJ/m³
875 kJ/m³

Thermal Diffusivity

61.7 mm²/s
64 mm²/s

Thermal Shock Resistance Index

33
38

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 scale70037129

Manufacturing and finishing

Capability70037129
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 7129 — frequently asked

Is 7129 stronger than 7003?

Yes. 7129 has a typical yield strength of 350 MPa (50.8 ksi) against 315 MPa (45.7 ksi) for 7003 — about 11% more. Tensile strength is 400 MPa (58 ksi) vs 360 MPa (52.2 ksi).

Which is cheaper, 7003 or 7129?

7003 is the lower-cost material: it sits in the standard tier ($$) while 7129 is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, 7003 or 7129?

7003. Its weldability rates very good (75/100) against poor (30/100) for 7129.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7003 and 7129 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.