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Aluminum 5182 vs 5251

Aluminum · grade comparison

Aluminum 5182 and 5251 are both aluminum grades, both corrosion resistant al. 5251 is the stronger of the two: yield strength 150 MPa (21.8 ksi) against 130 MPa (18.9 ksi) for 5182, about 15% more. In exchange, 5182 is the more ductile: elongation 21% versus 10% for 5251, and 5182 is harder (70 HB vs 57 HB). 5251 runs hotter in service (120°C vs 65°C continuous) and 5251 conducts heat better (155 W/m·K vs 123 W/m·K). On the shop floor, 5251 sits in a lower cost tier (budget, $) than 5182 (standard, $$).

5182Choose it when the part is bent, formed or impact-loaded.

5251Choose it when strength drives the design, or when the part sees heat.

5182 vs 5251: properties

51825251

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

275 MPa39.9 ksi
210 MPa30.5 ksi

Yield Strength (0.2% offset)

130 MPa18.9 ksi
150 MPa21.8 ksi

Elongation at Break

21%
10%

Shear Strength

170 MPa24.7 ksi
125 MPa18.1 ksi

Fatigue Strength (Endurance Limit)

140 MPa20.3 ksi
105 MPa15.2 ksi

Hardness, Brinell

70 HB
57 HB

Same in both: Elastic (Young's) Modulus 70 GPa10.2 Msi · Shear Modulus 26 GPa3.8 Msi · Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.65 g/cm³0.1 lb/in³
2.69 g/cm³0.1 lb/in³

Melting Point (Solidus)

577°C1,071 °F
607°C1,125 °F

Liquidus Temperature

638°C1,180 °F
650°C1,202 °F

Thermal

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

Thermal Conductivity

123 W/m·K71.1 BTU/hr·ft·°F
155 W/m·K89.6 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

24.1 µm/m·K13.4 µin/in·°F
23.8 µm/m·K13.2 µin/in·°F

Latent Heat of Fusion

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

Max Service Temperature (continuous)

65°C149 °F
120°C248 °F

Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

31 % IACS
34 % IACS

Electrical Resistivity

5.6×10⁻⁸ Ω·m2.2 µΩ·in
5.1×10⁻⁸ Ω·m2.01 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Same in both: Galvanic Potential (seawater, vs SCE) -0.86 V · Corrosion Resistance 72 / 100

Manufacturability

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

Machinability

40 / 100
45 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
35%

Weldability

85 / 100
88 / 100

Formability (cold)

88 / 100
72 / 100

Brazeability / Solderability

15 / 100
25 / 100

Polishability

60 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

55%
30%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 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)

104 kN·m/kg
78 kN·m/kg

Specific Stiffness (E / density)

26.4 MN·m/kg
26 MN·m/kg

Modulus of Resilience

121 kJ/m³
161 kJ/m³

Thermal Diffusivity

51.6 mm²/s
64 mm²/s

Same in both: Thermal Shock Resistance Index 20

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 scale51825251

Manufacturing and finishing

Capability51825251
Default condition——
Relative cost$$ Standard$ Budget
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.

5182 vs 5251 — frequently asked

Is 5251 stronger than 5182?

Yes. 5251 has a typical yield strength of 150 MPa (21.8 ksi) against 130 MPa (18.9 ksi) for 5182 — about 15% more. Tensile strength is 210 MPa (30.5 ksi) vs 275 MPa (39.9 ksi).

Which is cheaper, 5182 or 5251?

5251 is the lower-cost material: it sits in the budget tier ($) while 5182 is standard ($$). 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, 5182 or 5251?

5251, by a small margin. Both rate fair for machinability — 45/100 against 40/100 for 5182.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 5182 and 5251 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.