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IM8 vs T700S

Composite · grade comparison

IM8 and T700S are both composite grades. IM8 is the stronger of the two: tensile strength 5,930 MPa (860 ksi) against 4,900 MPa (711 ksi) for T700S, about 21% more. IM8 is stiffer (304 GPa vs 230 GPa) and IM8 runs hotter in service (400°C vs 350°C continuous).

IM8Choose it when strength drives the design, or when the part sees heat.

IM8 vs T700S: properties

IM8T700S

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

304 GPa44.1 Msi
230 GPa33.4 Msi

Tensile Strength (Ultimate)

5,930 MPa860 ksi
4,900 MPa711 ksi

Elongation at Break

2%
2.1%

Compressive Strength

2,900 MPa421 ksi
1,470 MPa213 ksi

Flexural Strength

—
1,620 MPa235 ksi

Flexural Modulus

—
120 GPa17.4 Msi

Shear Strength

—
98 MPa14.2 ksi

Same in both: Poisson's Ratio 0.27

Physical

Density and transition temperatures.

Density

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

Water Absorption (24 h)

0.05%
—

Thermal

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

Thermal Conductivity

5.4 W/m·K3.1 BTU/hr·ft·°F
9.4 W/m·K5.4 BTU/hr·ft·°F

Specific Heat Capacity

880 J/kg·K0.21 BTU/lb·°F
750 J/kg·K0.18 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

-0.55 µm/m·K-0.31 µin/in·°F
-0.38 µm/m·K-0.21 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Max Service Temperature (short-term)

600°C1,112 °F
500°C932 °F

Same in both: Min Service Temperature -269°C-452 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1.55×10⁻⁵ Ω·m610 µΩ·in
1.6×10⁻⁵ Ω·m630 µΩ·in

Volume Resistivity

—
0 Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
90 / 100

Same in both: UV / Weathering Resistance 60 / 100

Manufacturability

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

Machinability

20 / 100
25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

480 MJ/kg206,363 BTU/lb
400 MJ/kg171,969 BTU/lb

Embodied Carbon (primary production)

30 kg CO₂/kg
28 kg CO₂/kg

Embodied Water

700 L/kg83.9 gal/lb
—

Same in both: Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

3,313 kN·m/kg
2,722 kN·m/kg

Specific Stiffness (E / density)

169.8 MN·m/kg
127.8 MN·m/kg

Thermal Diffusivity

3.4 mm²/s
7 mm²/s

Thermal Shock Resistance Index

-192
-527

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

CapabilityIM8T700S
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

IM8 vs T700S — frequently asked

Is IM8 stronger than T700S?

Yes. IM8 has a typical tensile strength of 5,930 MPa (860 ksi) against 4,900 MPa (711 ksi) for T700S — about 21% more.

Which is cheaper, IM8 or T700S?

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, IM8 or T700S?

T700S, by a small margin. Both rate poor for machinability — 25/100 against 20/100 for IM8.

Ready to make it?

Upload a CAD file and FabDigit prices the part in IM8 and T700S 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.