Slate vs Soapstone
Natural Material · grade comparison
Slate and Soapstone are both natural material grades. Slate is the stronger of the two: tensile strength 16 MPa (2.32 ksi) against 10 MPa (1.45 ksi) for Soapstone, about 60% more. Slate is lighter (2.8 g/cm³ vs 2.95 g/cm³ for Soapstone) and Slate is stiffer (65 GPa vs 60 GPa). On the shop floor, Soapstone machines more easily (excellent vs good) and Slate sits in a lower cost tier (budget, $) than Soapstone (standard, $$).
SlateChoose 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.
Slate vs Soapstone: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all natural material 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 natural material 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.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Poisson's Ratio
Tensile Strength (Ultimate)
Elongation at Break
Compressive Strength
Flexural Strength
Shear Strength
Fracture Toughness (K_IC)
Hardness, Knoop
Hardness, Mohs
Physical
Density and transition temperatures.
Density
Porosity
Melting Point (Solidus)
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Thermal Expansion (CTE, 20–100 °C) 9 µm/m·K5 µin/in·°F
Electrical
Conductivity and insulation.
Electrical Resistivity
Dielectric Strength
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Polishability
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)
Specific Stiffness (E / density)
Thermal Diffusivity
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
| Capability | Slate | Soapstone |
|---|---|---|
| Default condition | — | — |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
Slate vs Soapstone — frequently asked
Is Slate stronger than Soapstone?
Yes. Slate has a typical tensile strength of 16 MPa (2.32 ksi) against 10 MPa (1.45 ksi) for Soapstone — about 60% more.
Which is cheaper, Slate or Soapstone?
Slate 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, Slate or Soapstone?
Soapstone. Its machinability rates excellent (90/100) against good (55/100) for Slate.
Ready to make it?
Upload a CAD file and FabDigit prices the part in Slate 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.