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Graphite vs WC-Co

Ceramic · grade comparison

Graphite and WC-Co are both ceramic grades. WC-Co is the stronger of the two: tensile strength 1,500 MPa (218 ksi) against 30 MPa (4.35 ksi) for Graphite, about 50 times as much. Graphite is lighter (1.78 g/cm³ vs 14.9 g/cm³ for WC-Co) and WC-Co is stiffer (630 GPa vs 11 GPa). On the shop floor, Graphite machines more easily (excellent vs not recommended).

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

WC-CoChoose it when strength drives the design, or when the part sees heat.

Graphite vs WC-Co: properties

GraphiteWC-Co

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

11 GPa1.6 Msi
630 GPa91.4 Msi

Shear Modulus

4.5 GPa0.65 Msi
250 GPa36.3 Msi

Bulk Modulus

7 GPa0.94 Msi
385 GPa55.8 Msi

Poisson's Ratio

0.2
0.22

Tensile Strength (Ultimate)

30 MPa4.4 ksi
1,500 MPa218 ksi

Compressive Strength

90 MPa13.1 ksi
5,800 MPa841 ksi

Flexural Strength

50 MPa7.3 ksi
2,100 MPa305 ksi

Shear Strength

28 MPa4.1 ksi
1,200 MPa174 ksi

Fracture Toughness (K_IC)

1 MPa·√m0.91 ksi·√in
9.5 MPa·√m8.6 ksi·√in

Hardness, Mohs

1.5
9

Elongation at Break

—
0%

Hardness, Vickers

—
1,600 HV

Hardness, Knoop

—
1,800 HK

Physical

Density and transition temperatures.

Density

1.78 g/cm³0.06 lb/in³
14.9 g/cm³0.54 lb/in³

Melting Point (Solidus)

3,650°C6,602 °F
1,320°C2,408 °F

Porosity

12%
0.04%

Thermal

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

Thermal Conductivity

110 W/m·K63.6 BTU/hr·ft·°F
90 W/m·K52 BTU/hr·ft·°F

Specific Heat Capacity

710 J/kg·K0.17 BTU/lb·°F
220 J/kg·K0.05 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

4.5 µm/m·K2.5 µin/in·°F
5.2 µm/m·K2.9 µin/in·°F

Max Service Temperature (continuous)

450°C842 °F
550°C1,022 °F

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

Electrical

Conductivity and insulation.

Electrical Resistivity

1.1×10⁻⁵ Ω·m433 µΩ·in
2×10⁻⁷ Ω·m7.87 µΩ·in

Volume Resistivity

0 Ω·cm
2×10⁻⁵ Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

80 / 100
55 / 100

Manufacturability

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

Machinability

92 / 100
3 / 100

Polishability

35 / 100
95 / 100

Sintering / Firing Temperature

2,900°C5,252 °F
1,420°C2,588 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

120 MJ/kg51,591 BTU/lb
400 MJ/kg171,969 BTU/lb

Embodied Carbon (primary production)

9 kg CO₂/kg
28 kg CO₂/kg

Embodied Water

90 L/kg10.8 gal/lb
350 L/kg41.9 gal/lb

Typical Recycled Content

10%
30%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

17 kN·m/kg
101 kN·m/kg

Specific Stiffness (E / density)

6.2 MN·m/kg
42.3 MN·m/kg

Thermal Diffusivity

87 mm²/s
27.5 mm²/s

Thermal Shock Resistance Index

67
41

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 scale

Manufacturing and finishing

CapabilityGraphiteWC-Co
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

Graphite vs WC-Co — frequently asked

Is WC-Co stronger than Graphite?

Yes. WC-Co has a typical tensile strength of 1,500 MPa (218 ksi) against 30 MPa (4.35 ksi) for Graphite — about 50 times as much.

Which is cheaper, Graphite or WC-Co?

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, Graphite or WC-Co?

Graphite. Its machinability rates excellent (92/100) against not recommended (3/100) for WC-Co.

Ready to make it?

Upload a CAD file and FabDigit prices the part in Graphite and WC-Co 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.