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EG Carbon Brush vs Impervious Graphite

Ceramic · grade comparison

EG Carbon Brush and Impervious Graphite are both ceramic grades. Impervious Graphite is the stronger of the two: tensile strength 25 MPa (3.63 ksi) against 14 MPa (2.03 ksi) for EG Carbon Brush, about 79% more. EG Carbon Brush is lighter (1.65 g/cm³ vs 1.8 g/cm³ for Impervious Graphite) and Impervious Graphite is stiffer (12 GPa vs 10 GPa). On the shop floor, EG Carbon Brush machines more easily (excellent vs very good).

EG Carbon BrushChoose it when weight is the constraint, or when the part sees heat.

Impervious GraphiteChoose it when strength drives the design.

EG Carbon Brush vs Impervious Graphite: properties

EG Carbon BrushImpervious Graphite

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

10 GPa1.5 Msi
12 GPa1.7 Msi

Shear Modulus

4.2 GPa0.61 Msi
—

Tensile Strength (Ultimate)

14 MPa2 ksi
25 MPa3.6 ksi

Compressive Strength

45 MPa6.5 ksi
95 MPa13.8 ksi

Flexural Strength

28 MPa4.1 ksi
50 MPa7.3 ksi

Shear Strength

12 MPa1.7 ksi
18 MPa2.6 ksi

Fracture Toughness (K_IC)

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

Hardness, Mohs

1.5
2

Elongation at Break

—
0.3%

Hardness, Vickers

—
50 HV

Same in both: Poisson's Ratio 0.2

Physical

Density and transition temperatures.

Density

1.65 g/cm³0.06 lb/in³
1.8 g/cm³0.07 lb/in³

Melting Point (Solidus)

3,650°C6,602 °F
—

Porosity

22%
0.5%

Thermal

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

Thermal Conductivity

45 W/m·K26 BTU/hr·ft·°F
125 W/m·K72.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Max Service Temperature (continuous)

350°C662 °F
170°C338 °F

Same in both: Specific Heat Capacity 710 J/kg·K0.17 BTU/lb·°F · Min Service Temperature -50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

4×10⁻⁵ Ω·m1,575 µΩ·in
1.2×10⁻⁵ Ω·m472 µΩ·in

Volume Resistivity

0 Ω·cm
0 Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
88 / 100

Manufacturability

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

Machinability

95 / 100
80 / 100

Polishability

35 / 100
45 / 100

Sintering / Firing Temperature

2,600°C4,712 °F
2,800°C5,072 °F

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

130 MJ/kg55,890 BTU/lb
190 MJ/kg81,685 BTU/lb

Embodied Carbon (primary production)

9 kg CO₂/kg
14 kg CO₂/kg

Embodied Water

60 L/kg7.2 gal/lb
—

Typical Recycled Content

5%
0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

8 kN·m/kg
14 kN·m/kg

Specific Stiffness (E / density)

6.1 MN·m/kg
6.7 MN·m/kg

Thermal Diffusivity

38.4 mm²/s
97.8 mm²/s

Thermal Shock Resistance Index

16
58

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

CapabilityEG Carbon BrushImpervious Graphite
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

EG Carbon Brush vs Impervious Graphite — frequently asked

Is Impervious Graphite stronger than EG Carbon Brush?

Yes. Impervious Graphite has a typical tensile strength of 25 MPa (3.63 ksi) against 14 MPa (2.03 ksi) for EG Carbon Brush — about 79% more.

Which is cheaper, EG Carbon Brush or Impervious Graphite?

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, EG Carbon Brush or Impervious Graphite?

EG Carbon Brush. Its machinability rates excellent (95/100) against very good (80/100) for Impervious Graphite.

Ready to make it?

Upload a CAD file and FabDigit prices the part in EG Carbon Brush and Impervious Graphite 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.