FabDigitFabDigit

Aluminum AlSi12 vs EN AC-21100

Aluminum · grade comparison

Aluminum AlSi12 and EN AC-21100 are both aluminum grades. AlSi12 is the stronger of the two: yield strength 250 MPa (36.3 ksi) against 210 MPa (30.5 ksi) for EN AC-21100, about 19% more; tensile strength follows at 400 MPa (58 ksi) vs 320 MPa (46.4 ksi). In exchange, EN AC-21100 is the more ductile: elongation 6% versus 5% for AlSi12, and AlSi12 is harder (105 HB vs 95 HB). EN AC-21100 runs hotter in service (200°C vs 120°C continuous) and EN AC-21100 conducts heat better (135 W/m·K vs 120 W/m·K). On the shop floor, EN AC-21100 machines more easily (very good vs fair), AlSi12 welds better (very good vs poor), and EN AC-21100 sits in a lower cost tier (standard, $$) than AlSi12 (premium, $$$).

AlSi12Choose it when strength drives the design, or when it will be welded.

EN AC-21100Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

AlSi12 vs EN AC-21100: properties

AlSi12EN AC-21100

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

74 GPa10.7 Msi
71 GPa10.3 Msi

Tensile Strength (Ultimate)

400 MPa58 ksi
320 MPa46.4 ksi

Yield Strength (0.2% offset)

250 MPa36.3 ksi
210 MPa30.5 ksi

Elongation at Break

5%
6%

Compressive Strength

420 MPa60.9 ksi
215 MPa31.2 ksi

Shear Strength

240 MPa34.8 ksi
205 MPa29.7 ksi

Fatigue Strength (Endurance Limit)

100 MPa14.5 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

17 MPa·√m15.5 ksi·√in
24 MPa·√m21.8 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

105 HB
95 HB

Hardness, Vickers

115 HV
100 HV

Same in both: Elastic (Young's) Modulus 72 GPa10.4 Msi · Shear Modulus 27 GPa3.9 Msi · Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.67 g/cm³0.1 lb/in³
2.75 g/cm³0.1 lb/in³

Melting Point (Solidus)

574°C1,065 °F
545°C1,013 °F

Liquidus Temperature

585°C1,085 °F
650°C1,202 °F

Thermal

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

Thermal Conductivity

120 W/m·K69.3 BTU/hr·ft·°F
135 W/m·K78 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

20.4 µm/m·K11.3 µin/in·°F
22.5 µm/m·K12.5 µin/in·°F

Latent Heat of Fusion

510 J/g219 BTU/lb
390 J/g168 BTU/lb

Max Service Temperature (continuous)

120°C248 °F
200°C392 °F

Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
33 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
5.2×10⁻⁸ Ω·m2.05 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.83 V
-0.69 V

Corrosion Resistance

55 / 100
35 / 100

Manufacturability

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

Machinability

50 / 100
80 / 100

Weldability

80 / 100
25 / 100

Castability

95 / 100
40 / 100

Brazeability / Solderability

35 / 100
20 / 100

Machinability Rating (AISI 1212 = 100 %)

—
200%

Same in both: Formability (cold) 15 / 100 · Polishability 55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

215 MJ/kg92,433 BTU/lb
150 MJ/kg64,488 BTU/lb

Embodied Carbon (primary production)

13 kg CO₂/kg
9.5 kg CO₂/kg

Embodied Water

1,200 L/kg144 gal/lb
1,100 L/kg132 gal/lb

Typical Recycled Content

10%
25%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

150 kN·m/kg
116 kN·m/kg

Specific Stiffness (E / density)

27 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

434 kJ/m³
306 kJ/m³

Thermal Diffusivity

49.9 mm²/s
54.5 mm²/s

Thermal Shock Resistance Index

33
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 scaleAlSi12EN AC-21100

Manufacturing and finishing

CapabilityAlSi12EN AC-21100
3D printingYes—
Default conditionAs Printed—
Relative cost$$$ Premium$$ Standard
Min. machined wall——
Best machined surface——
Anodized (Aluminum AM)Yes—
Plated (Metal AM)Yes—

They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

AlSi12 vs EN AC-21100 — frequently asked

Is AlSi12 stronger than EN AC-21100?

Yes. AlSi12 has a typical yield strength of 250 MPa (36.3 ksi) against 210 MPa (30.5 ksi) for EN AC-21100 — about 19% more. Tensile strength is 400 MPa (58 ksi) vs 320 MPa (46.4 ksi).

Which is cheaper, AlSi12 or EN AC-21100?

EN AC-21100 is the lower-cost material: it sits in the standard tier ($$) while AlSi12 is premium ($$$). 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, AlSi12 or EN AC-21100?

EN AC-21100. Its machinability rates very good (80/100) against fair (50/100) for AlSi12; for welding the order is AlSi12 first (very good, 80/100) then EN AC-21100 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AlSi12 and EN AC-21100 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.