Aluminum AC2A vs AC4B
Aluminum · grade comparison
Aluminum AC2A and AC4B are both aluminum grades. AC2A is the stronger of the two: yield strength 170 MPa (24.7 ksi) against 110 MPa (16 ksi) for AC4B, about 55% more; tensile strength follows at 250 MPa (36.3 ksi) vs 180 MPa (26.1 ksi). AC2A is harder — 85 HB against 75 HB for AC4B — which matters for wear surfaces and threads. AC2A runs hotter in service (175°C vs 150°C continuous). On the shop floor, AC4B welds better (45 vs 35 out of 100).
AC2AChoose it when strength drives the design, or when surface hardness matters.
AC4BChoose it when it will be welded.
AC2A vs AC4B: 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.
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 74 GPa10.7 Msi · Shear Modulus 27.5 GPa4 Msi · Bulk Modulus 72 GPa10.4 Msi · Poisson's Ratio 0.33 · Elongation at Break 2% · Fracture Toughness (K_IC) 18 MPa·√m16.4 ksi·√in · Charpy V-Notch Impact (RT) 3 J2.2 ft·lbf
Physical
Density and transition temperatures.
Same in both: Density 2.79 g/cm³0.1 lb/in³ · Melting Point (Solidus) 516°C961 °F · Liquidus Temperature 604°C1,119 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 21.5 µm/m·K11.9 µin/in·°F · Latent Heat of Fusion 389 J/g167 BTU/lb
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 27 % IACS · Electrical Resistivity 6.4×10⁻⁸ Ω·m2.52 µΩ·in
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)
Castability
Same in both: Brazeability / Solderability 25 / 100 · Polishability 40 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 26.5 MN·m/kg
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 | AC2A | AC4B |
|---|---|---|
| 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.
AC2A vs AC4B — frequently asked
Is AC2A stronger than AC4B?
Yes. AC2A has a typical yield strength of 170 MPa (24.7 ksi) against 110 MPa (16 ksi) for AC4B — about 55% more. Tensile strength is 250 MPa (36.3 ksi) vs 180 MPa (26.1 ksi).
Which is cheaper, AC2A or AC4B?
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 welds better, AC2A or AC4B?
AC4B. Its weldability rates fair (45/100) against fair (35/100) for AC2A.
Ready to make it?
Upload a CAD file and FabDigit prices the part in AC2A and AC4B 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.