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Aluminum AC4A vs AC4CH

Aluminum · grade comparison

Aluminum AC4A and AC4CH are both aluminum grades. AC4CH is the stronger of the two: tensile strength 280 MPa (40.6 ksi) against 260 MPa (37.7 ksi) for AC4A, about 8% more. AC4CH is the more ductile: elongation 8% versus 3% for AC4A, and AC4A is harder (90 HB vs 85 HB). On the shop floor, AC4CH machines more easily (good vs fair) and AC4CH welds better (very good vs good).

AC4CHChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

AC4A vs AC4CH: properties

AC4AAC4CH

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

71 GPa10.3 Msi
72.4 GPa10.5 Msi

Shear Modulus

26.5 GPa3.8 Msi
27 GPa3.9 Msi

Bulk Modulus

70 GPa10.2 Msi
71 GPa10.3 Msi

Tensile Strength (Ultimate)

260 MPa37.7 ksi
280 MPa40.6 ksi

Yield Strength (0.2% offset)

200 MPa29 ksi
210 MPa30.5 ksi

Elongation at Break

3%
8%

Compressive Strength

205 MPa29.7 ksi
215 MPa31.2 ksi

Shear Strength

180 MPa26.1 ksi
200 MPa29 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
25 MPa·√m22.8 ksi·√in

Hardness, Brinell

90 HB
85 HB

Same in both: Poisson's Ratio 0.33 · Fatigue Strength (Endurance Limit) 90 MPa13.1 ksi · Charpy V-Notch Impact (RT) 4 J3 ft·lbf

Physical

Density and transition temperatures.

Liquidus Temperature

596°C1,105 °F
613°C1,135 °F

Same in both: Density 2.68 g/cm³0.1 lb/in³ · Melting Point (Solidus) 557°C1,035 °F

Thermal

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

Thermal Conductivity

150 W/m·K86.7 BTU/hr·ft·°F
151 W/m·K87.2 BTU/hr·ft·°F

Latent Heat of Fusion

425 J/g183 BTU/lb
389 J/g167 BTU/lb

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 · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 39 % IACS · Electrical Resistivity 4.4×10⁻⁸ Ω·m1.73 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

58 / 100
55 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V

Manufacturability

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

Machinability

50 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
70%

Weldability

65 / 100
75 / 100

Formability (cold)

10 / 100
15 / 100

Castability

88 / 100
92 / 100

Brazeability / Solderability

25 / 100
30 / 100

Polishability

45 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

155 MJ/kg66,638 BTU/lb
200 MJ/kg85,985 BTU/lb

Embodied Carbon (primary production)

9.5 kg CO₂/kg
12.5 kg CO₂/kg

Typical Recycled Content

70%
20%

Same in both: Embodied Water 1,100 L/kg132 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

97 kN·m/kg
104 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
27 MN·m/kg

Modulus of Resilience

282 kJ/m³
305 kJ/m³

Thermal Diffusivity

58.1 mm²/s
58.5 mm²/s

Thermal Shock Resistance Index

26
27

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 scaleAC4AAC4CH

Manufacturing and finishing

CapabilityAC4AAC4CH
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 AC4CH — frequently asked

Is AC4CH stronger than AC4A?

Yes. AC4CH has a typical tensile strength of 280 MPa (40.6 ksi) against 260 MPa (37.7 ksi) for AC4A — about 8% more.

Which is cheaper, AC4A or AC4CH?

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 AC4CH?

AC4CH. Its machinability rates good (60/100) against fair (50/100) for AC4A; for welding the order is AC4CH first (very good, 75/100) then AC4A (good, 65/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC4A and AC4CH 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.