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Aluminum AlSi7Mg vs EN AC-51100

Aluminum · grade comparison

Aluminum AlSi7Mg and EN AC-51100 are both aluminum grades. AlSi7Mg is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 80 MPa (11.6 ksi) for EN AC-51100, about 3.0 times as much; tensile strength follows at 350 MPa (50.8 ksi) vs 150 MPa (21.8 ksi). AlSi7Mg is the more ductile: elongation 8% versus 4% for EN AC-51100, and AlSi7Mg is harder (105 HB vs 50 HB). EN AC-51100 conducts heat better (145 W/m·K vs 130 W/m·K). On the shop floor, EN AC-51100 machines more easily (very good vs good), EN AC-51100 welds better (80 vs 70 out of 100), and EN AC-51100 sits in a lower cost tier (standard, $$) than AlSi7Mg (premium, $$$).

AlSi7MgChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

EN AC-51100Choose it when the part is machined in volume, or when it will be welded.

AlSi7Mg vs EN AC-51100: properties

AlSi7MgEN AC-51100

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

71 GPa10.3 Msi
70 GPa10.2 Msi

Shear Modulus

26.5 GPa3.8 Msi
26 GPa3.8 Msi

Bulk Modulus

69 GPa10 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

350 MPa50.8 ksi
150 MPa21.8 ksi

Yield Strength (0.2% offset)

240 MPa34.8 ksi
80 MPa11.6 ksi

Elongation at Break

8%
4%

Compressive Strength

250 MPa36.3 ksi
—

Shear Strength

215 MPa31.2 ksi
95 MPa13.8 ksi

Fatigue Strength (Endurance Limit)

100 MPa14.5 ksi
55 MPa8 ksi

Fracture Toughness (K_IC)

20 MPa·√m18.2 ksi·√in
—

Charpy V-Notch Impact (RT)

6 J4.4 ft·lbf
12 J8.9 ft·lbf

Hardness, Brinell

105 HB
50 HB

Hardness, Vickers

115 HV
55 HV

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

557°C1,035 °F
600°C1,112 °F

Liquidus Temperature

613°C1,135 °F
640°C1,184 °F

Thermal

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

Thermal Conductivity

130 W/m·K75.1 BTU/hr·ft·°F
145 W/m·K83.8 BTU/hr·ft·°F

Specific Heat Capacity

963 J/kg·K0.23 BTU/lb·°F
900 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
24 µm/m·K13.3 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
390 J/g168 BTU/lb

Same in both: Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

28 % IACS
25 % IACS

Electrical Resistivity

6.2×10⁻⁸ Ω·m2.44 µΩ·in
6.9×10⁻⁸ Ω·m2.72 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.83 V
-0.87 V

Corrosion Resistance

58 / 100
80 / 100

Manufacturability

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

Machinability

58 / 100
70 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
190%

Weldability

70 / 100
80 / 100

Formability (cold)

20 / 100
15 / 100

Castability

90 / 100
42 / 100

Brazeability / Solderability

30 / 100
25 / 100

Polishability

60 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

215 MJ/kg92,433 BTU/lb
200 MJ/kg85,985 BTU/lb

Embodied Carbon (primary production)

13 kg CO₂/kg
12.5 kg CO₂/kg

Embodied Water

1,200 L/kg144 gal/lb
1,150 L/kg138 gal/lb

Typical Recycled Content

10%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

131 kN·m/kg
56 kN·m/kg

Specific Stiffness (E / density)

26.6 MN·m/kg
26.3 MN·m/kg

Modulus of Resilience

406 kJ/m³
46 kJ/m³

Thermal Diffusivity

50.6 mm²/s
60.6 mm²/s

Thermal Shock Resistance Index

30
13

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 scaleEN AC-51100AlSi7Mg

Manufacturing and finishing

CapabilityAlSi7MgEN AC-51100
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.

AlSi7Mg vs EN AC-51100 — frequently asked

Is AlSi7Mg stronger than EN AC-51100?

Yes. AlSi7Mg has a typical yield strength of 240 MPa (34.8 ksi) against 80 MPa (11.6 ksi) for EN AC-51100 — about 3.0 times as much. Tensile strength is 350 MPa (50.8 ksi) vs 150 MPa (21.8 ksi).

Which is cheaper, AlSi7Mg or EN AC-51100?

EN AC-51100 is the lower-cost material: it sits in the standard tier ($$) while AlSi7Mg is premium ($$$). 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, AlSi7Mg or EN AC-51100?

EN AC-51100. Its machinability rates very good (70/100) against good (58/100) for AlSi7Mg; for welding the order is EN AC-51100 first (very good, 80/100) then AlSi7Mg (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AlSi7Mg and EN AC-51100 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.