Aluminum AC4A vs AC4D
Aluminum · grade comparison
Aluminum AC4A and AC4D are both aluminum grades. AC4A is the stronger of the two: yield strength 200 MPa (29 ksi) against 180 MPa (26.1 ksi) for AC4D, about 11% more. AC4A is the more ductile: elongation 3% versus 2.5% for AC4D. On the shop floor, AC4D machines more easily (good vs fair) and AC4A welds better (good vs fair).
AC4AChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.
AC4DChoose it when the part is machined in volume.
AC4A vs AC4D: 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.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.5 GPa3.8 Msi · Poisson's Ratio 0.33 · Charpy V-Notch Impact (RT) 4 J3 ft·lbf
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)
Min Service Temperature
Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 425 J/g183 BTU/lb · Max Service Temperature (continuous) 150°C302 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 39 % IACS
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
Castability
Same in both: Formability (cold) 10 / 100 · Brazeability / Solderability 25 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Same in both: Typical Recycled Content 70%
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 | AC4A | AC4D |
|---|---|---|
| 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.
AC4A vs AC4D — frequently asked
Is AC4A stronger than AC4D?
Yes. AC4A has a typical yield strength of 200 MPa (29 ksi) against 180 MPa (26.1 ksi) for AC4D — about 11% more. Tensile strength is 260 MPa (37.7 ksi) vs 250 MPa (36.3 ksi).
Which is cheaper, AC4A or AC4D?
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, AC4A or AC4D?
AC4D. Its machinability rates good (62/100) against fair (50/100) for AC4A; for welding the order is AC4A first (good, 65/100) then AC4D (fair, 40/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC4A and AC4D 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.