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Cordierite vs Mullite

Ceramic · grade comparison

Cordierite and Mullite are both ceramic grades. Mullite is the stronger of the two: tensile strength 80 MPa (11.6 ksi) against 25 MPa (3.63 ksi) for Cordierite, about 3.2 times as much. Mullite is harder — 1,100 HV against 700 HV for Cordierite — which matters for wear surfaces and threads. Cordierite is lighter (2.3 g/cm³ vs 2.9 g/cm³ for Mullite) and Mullite is stiffer (150 GPa vs 70 GPa). On the shop floor, Cordierite machines more easily (poor vs not recommended) and Mullite sits in a lower cost tier (premium, $$$) than Cordierite (high, $$$$).

CordieriteChoose it when weight is the constraint, or when the part is machined in volume.

MulliteChoose it when strength drives the design, or when surface hardness matters.

Cordierite vs Mullite: properties

CordieriteMullite

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70 GPa10.2 Msi
150 GPa21.8 Msi

Shear Modulus

28 GPa4.1 Msi
60 GPa8.7 Msi

Bulk Modulus

47 GPa6.8 Msi
145 GPa21 Msi

Tensile Strength (Ultimate)

25 MPa3.6 ksi
80 MPa11.6 ksi

Compressive Strength

350 MPa50.8 ksi
700 MPa102 ksi

Flexural Strength

70 MPa10.2 ksi
170 MPa24.7 ksi

Fracture Toughness (K_IC)

1.5 MPa·√m1.4 ksi·√in
2.2 MPa·√m2 ksi·√in

Hardness, Vickers

700 HV
1,100 HV

Hardness, Mohs

7
7.5

Elongation at Break

—
0%

Shear Strength

—
115 MPa16.7 ksi

Hardness, Knoop

—
1,000 HK

Same in both: Poisson's Ratio 0.25

Physical

Density and transition temperatures.

Density

2.3 g/cm³0.08 lb/in³
2.9 g/cm³0.1 lb/in³

Melting Point (Solidus)

1,465°C2,669 °F
1,840°C3,344 °F

Porosity

8%
1%

Refractive Index

—
1.64

Thermal

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

Thermal Conductivity

2.5 W/m·K1.4 BTU/hr·ft·°F
5 W/m·K2.9 BTU/hr·ft·°F

Specific Heat Capacity

800 J/kg·K0.19 BTU/lb·°F
880 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

2 µm/m·K1.1 µin/in·°F
4.5 µm/m·K2.5 µin/in·°F

Max Service Temperature (continuous)

1,250°C2,282 °F
1,550°C2,822 °F

Same in both: Min Service Temperature -200°C-328 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹¹ Ω·m3.94×10¹⁸ µΩ·in
1×10¹² Ω·m3.94×10¹⁹ µΩ·in

Dielectric Strength

10 kV/mm254 V/mil
12 kV/mm305 V/mil

Dielectric Constant (1 MHz)

5
6.5

Dissipation Factor (1 MHz)

0.004
0.003

Volume Resistivity

1×10¹³ Ω·cm
1×10¹⁴ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

70 / 100
80 / 100

Manufacturability

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

Machinability

20 / 100
5 / 100

Polishability

35 / 100
60 / 100

Sintering / Firing Temperature

1,350°C2,462 °F
1,650°C3,002 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

30 MJ/kg12,898 BTU/lb
45 MJ/kg19,347 BTU/lb

Embodied Carbon (primary production)

2.2 kg CO₂/kg
3.2 kg CO₂/kg

Embodied Water

20 L/kg2.4 gal/lb
90 L/kg10.8 gal/lb

Same in both: Typical Recycled Content 5%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

11 kN·m/kg
28 kN·m/kg

Specific Stiffness (E / density)

30.4 MN·m/kg
51.7 MN·m/kg

Thermal Diffusivity

1.4 mm²/s
2 mm²/s

Thermal Shock Resistance Index

0
1

Strength versus weight

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

501002005001,000234567Density (g/cm³)Yield strength (MPa) — log scaleCordierite

Manufacturing and finishing

CapabilityCordieriteMullite
Default condition——
Relative cost$$$$ High$$$ Premium
Min. machined wall——
Best machined surface——

Cordierite vs Mullite — frequently asked

Is Mullite stronger than Cordierite?

Yes. Mullite has a typical tensile strength of 80 MPa (11.6 ksi) against 25 MPa (3.63 ksi) for Cordierite — about 3.2 times as much.

Which is cheaper, Cordierite or Mullite?

Mullite is the lower-cost material: it sits in the premium tier ($$$) while Cordierite is high ($$$$). 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, Cordierite or Mullite?

Cordierite. Its machinability rates poor (20/100) against not recommended (5/100) for Mullite.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Cordierite and Mullite 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.