FabDigitFabDigit

Ox/Ox vs Si3N4/SiCw

Composite · grade comparison

Ox/Ox and Si3N4/SiCw are both composite grades. Si3N4/SiCw is the stronger of the two: tensile strength 500 MPa (72.5 ksi) against 190 MPa (27.6 ksi) for Ox/Ox, about 163% more. In exchange, Ox/Ox is the more ductile: elongation 0.3% versus 0.15% for Si3N4/SiCw. Ox/Ox is lighter (2.75 g/cm³ vs 3.22 g/cm³ for Si3N4/SiCw) and Si3N4/SiCw is stiffer (320 GPa vs 75 GPa). On the shop floor, Ox/Ox machines more easily (poor vs not recommended).

Ox/OxChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

Si3N4/SiCwChoose it when strength drives the design.

Ox/Ox vs Si3N4/SiCw: properties

Ox/OxSi3N4/SiCw

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

75 GPa10.9 Msi
320 GPa46.4 Msi

Shear Modulus

25 GPa3.6 Msi
126 GPa18.3 Msi

Poisson's Ratio

0.12
0.27

Tensile Strength (Ultimate)

190 MPa27.6 ksi
500 MPa72.5 ksi

Elongation at Break

0.3%
0.15%

Compressive Strength

200 MPa29 ksi
3,000 MPa435 ksi

Compressive Modulus

70 GPa10.2 Msi
—

Flexural Strength

250 MPa36.3 ksi
900 MPa131 ksi

Flexural Modulus

65 GPa9.4 Msi
315 GPa45.7 Msi

Shear Strength

10 MPa1.5 ksi
350 MPa50.8 ksi

Fracture Toughness (K_IC)

8 MPa·√m7.3 ksi·√in
8.5 MPa·√m7.7 ksi·√in

Bulk Modulus

—
232 GPa33.6 Msi

Physical

Density and transition temperatures.

Density

2.75 g/cm³0.1 lb/in³
3.22 g/cm³0.12 lb/in³

Water Absorption (Saturation)

8%
—

Thermal

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

Thermal Conductivity

2 W/m·K1.2 BTU/hr·ft·°F
32 W/m·K18.5 BTU/hr·ft·°F

Specific Heat Capacity

1,000 J/kg·K0.24 BTU/lb·°F
700 J/kg·K0.17 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

6 µm/m·K3.3 µin/in·°F
3.4 µm/m·K1.9 µin/in·°F

Max Service Temperature (continuous)

1,200°C2,192 °F
1,300°C2,372 °F

Max Service Temperature (short-term)

1,300°C2,372 °F
1,500°C2,732 °F

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

Electrical

Conductivity and insulation.

Electrical Resistivity

1×10¹⁰ Ω·m3.94×10¹⁷ µΩ·in
1×10⁸ Ω·m3.94×10¹⁵ µΩ·in

Dielectric Constant (1 MHz)

5
9.5

Dissipation Factor (1 MHz)

0.008
—

Volume Resistivity

—
1×10¹⁰ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

92 / 100
88 / 100

Same in both: UV / Weathering Resistance 100 / 100

Manufacturability

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

Machinability

15 / 100
4 / 100

Polishability

25 / 100
90 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

600 MJ/kg257,954 BTU/lb
400 MJ/kg171,969 BTU/lb

Embodied Carbon (primary production)

45 kg CO₂/kg
30 kg CO₂/kg

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

69 kN·m/kg
155 kN·m/kg

Specific Stiffness (E / density)

27.3 MN·m/kg
99.4 MN·m/kg

Thermal Diffusivity

0.7 mm²/s
14.2 mm²/s

Thermal Shock Resistance Index

1
15

Strength versus weight

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

1101001,000510Density (g/cm³)Yield strength (MPa) — log scale

Manufacturing and finishing

CapabilityOx/OxSi3N4/SiCw
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Ox/Ox vs Si3N4/SiCw — frequently asked

Is Si3N4/SiCw stronger than Ox/Ox?

Yes. Si3N4/SiCw has a typical tensile strength of 500 MPa (72.5 ksi) against 190 MPa (27.6 ksi) for Ox/Ox — about 163% more.

Which is cheaper, Ox/Ox or Si3N4/SiCw?

Both sit in the same relative cost tier ($$$$, high); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, Ox/Ox or Si3N4/SiCw?

Ox/Ox. Its machinability rates poor (15/100) against not recommended (4/100) for Si3N4/SiCw.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Ox/Ox and Si3N4/SiCw 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.