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Granite vs Soapstone

Natural Material · grade comparison

Granite and Soapstone are both natural material grades. Granite is the stronger of the two: tensile strength 12 MPa (1.74 ksi) against 10 MPa (1.45 ksi) for Soapstone, about 20% more. Granite is lighter (2.68 g/cm³ vs 2.95 g/cm³ for Soapstone) and Soapstone is stiffer (60 GPa vs 50 GPa). On the shop floor, Soapstone machines more easily (excellent vs poor) and Granite sits in a lower cost tier (budget, $) than Soapstone (standard, $$).

GraniteChoose it when strength drives the design, or when weight is the constraint.

SoapstoneChoose it when the part sees heat, or when the part is machined in volume.

Granite vs Soapstone: properties

GraniteSoapstone

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

50 GPa7.3 Msi
60 GPa8.7 Msi

Shear Modulus

21 GPa3 Msi
20 GPa2.9 Msi

Bulk Modulus

40 GPa5.8 Msi
36 GPa5.2 Msi

Poisson's Ratio

0.22
0.27

Tensile Strength (Ultimate)

12 MPa1.7 ksi
10 MPa1.5 ksi

Elongation at Break

0.05%
—

Compressive Strength

180 MPa26.1 ksi
85 MPa12.3 ksi

Flexural Strength

14 MPa2 ksi
18 MPa2.6 ksi

Shear Strength

20 MPa2.9 ksi
18 MPa2.6 ksi

Fracture Toughness (K_IC)

1.2 MPa·√m1.1 ksi·√in
1 MPa·√m0.91 ksi·√in

Hardness, Knoop

650 HK
60 HK

Hardness, Mohs

6.5
3

Physical

Density and transition temperatures.

Density

2.68 g/cm³0.1 lb/in³
2.95 g/cm³0.11 lb/in³

Melting Point (Solidus)

1,215°C2,219 °F
1,500°C2,732 °F

Porosity

0.7%
0.6%

Thermal

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

Thermal Conductivity

2.9 W/m·K1.7 BTU/hr·ft·°F
6 W/m·K3.5 BTU/hr·ft·°F

Specific Heat Capacity

800 J/kg·K0.19 BTU/lb·°F
980 J/kg·K0.23 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

8 µm/m·K4.4 µin/in·°F
9 µm/m·K5 µin/in·°F

Max Service Temperature (continuous)

300°C572 °F
900°C1,652 °F

Same in both: Min Service Temperature -60°C-76 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

10,000 Ω·m3.94×10¹¹ µΩ·in
1×10⁸ Ω·m3.94×10¹⁵ µΩ·in

Dielectric Strength

—
6 kV/mm152 V/mil

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

88 / 100
92 / 100

Manufacturability

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

Machinability

25 / 100
90 / 100

Polishability

85 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

6 MJ/kg2,580 BTU/lb
2 MJ/kg860 BTU/lb

Embodied Carbon (primary production)

0.45 kg CO₂/kg
0.14 kg CO₂/kg

Embodied Water

12 L/kg1.4 gal/lb
20 L/kg2.4 gal/lb

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

4 kN·m/kg
3 kN·m/kg

Specific Stiffness (E / density)

18.7 MN·m/kg
20.3 MN·m/kg

Thermal Diffusivity

1.4 mm²/s
2.1 mm²/s

Same in both: Thermal Shock Resistance Index 0

Strength versus weight

Yield strength against density for every natural material grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

Manufacturing and finishing

CapabilityGraniteSoapstone
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall——
Best machined surface——

Granite vs Soapstone — frequently asked

Is Granite stronger than Soapstone?

Yes. Granite has a typical tensile strength of 12 MPa (1.74 ksi) against 10 MPa (1.45 ksi) for Soapstone — about 20% more.

Which is cheaper, Granite or Soapstone?

Granite is the lower-cost material: it sits in the budget tier ($) while Soapstone is standard ($$). 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, Granite or Soapstone?

Soapstone. Its machinability rates excellent (90/100) against poor (25/100) for Granite.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Granite and Soapstone 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.