Aluminum AC3A vs AC4C
Aluminum · grade comparison
Aluminum AC3A and AC4C are both aluminum grades. AC4C is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 75 MPa (10.9 ksi) for AC3A, about 140% more; tensile strength follows at 250 MPa (36.3 ksi) vs 165 MPa (23.9 ksi). In exchange, AC3A is the more ductile: elongation 6% versus 5% for AC4C, and AC4C is harder (80 HB vs 50 HB). AC4C conducts heat better (151 W/m·K vs 130 W/m·K). On the shop floor, AC4C machines more easily (good vs fair).
AC3AChoose it when the part is bent, formed or impact-loaded.
AC4CChoose it when strength drives the design, or when the part is machined in volume.
AC3A vs AC4C: 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
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Brinell
Compressive Strength
Hardness, Vickers
Same in both: 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
Thermal Expansion (CTE, 20–100 °C)
Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V · Corrosion Resistance 58 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 1,200 L/kg144 gal/lb
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 | AC3A | AC4C |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Both take the same 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.
AC3A vs AC4C — frequently asked
Is AC4C stronger than AC3A?
Yes. AC4C has a typical yield strength of 180 MPa (26.1 ksi) against 75 MPa (10.9 ksi) for AC3A — about 140% more. Tensile strength is 250 MPa (36.3 ksi) vs 165 MPa (23.9 ksi).
Which is cheaper, AC3A or AC4C?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, AC3A or AC4C?
AC4C. Its machinability rates good (62/100) against fair (40/100) for AC3A; for welding the order is AC3A first (very good, 80/100) then AC4C (very good, 75/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC3A and AC4C 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.