Aluminum 5056 vs 5251
Aluminum · grade comparison
Aluminum 5056 and 5251 are both aluminum grades, both corrosion resistant al. 5056 is the stronger of the two: yield strength 235 MPa (34.1 ksi) against 150 MPa (21.8 ksi) for 5251, about 57% more; tensile strength follows at 330 MPa (47.9 ksi) vs 210 MPa (30.5 ksi). 5056 is the more ductile: elongation 20% versus 10% for 5251, and 5056 is harder (78 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 112 W/m·K). On the shop floor, 5056 machines more easily (good vs fair) and 5251 sits in a lower cost tier (budget, $) than 5056 (standard, $$).
5056Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
5251Choose it when the part sees heat, or when cost is the deciding factor.
5056 vs 5251: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Same in both: Latent Heat of Fusion 395 J/g170 BTU/lb · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
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 · Typical Recycled Content 30%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 5056 | 5251 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $ Budget |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 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.
5056 vs 5251 — frequently asked
Is 5056 stronger than 5251?
Yes. 5056 has a typical yield strength of 235 MPa (34.1 ksi) against 150 MPa (21.8 ksi) for 5251 — about 57% more. Tensile strength is 330 MPa (47.9 ksi) vs 210 MPa (30.5 ksi).
Which is cheaper, 5056 or 5251?
5251 is the lower-cost material: it sits in the budget tier ($) while 5056 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, 5056 or 5251?
5056. Its machinability rates good (55/100) against fair (45/100) for 5251.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 5056 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.