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AS4D vs T700S

Composite · grade comparison

AS4D and T700S are both composite grades. T700S is the stronger of the two: tensile strength 4,900 MPa (711 ksi) against 4,480 MPa (650 ksi) for AS4D, about 9% more. T700S is the more ductile: elongation 2.1% versus 1.8% for AS4D. AS4D is stiffer (245 GPa vs 230 GPa) and AS4D runs hotter in service (400°C vs 350°C continuous). On the shop floor, T700S machines more easily (25 vs 15 out of 100).

AS4DChoose it when the part sees heat.

T700SChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

AS4D vs T700S: properties

AS4DT700S

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

245 GPa35.5 Msi
230 GPa33.4 Msi

Tensile Strength (Ultimate)

4,480 MPa650 ksi
4,900 MPa711 ksi

Elongation at Break

1.8%
2.1%

Compressive Strength

—
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

Thermal

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

Thermal Conductivity

6.8 W/m·K3.9 BTU/hr·ft·°F
9.4 W/m·K5.4 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

-0.6 µm/m·K-0.33 µin/in·°F
-0.38 µm/m·K-0.21 µin/in·°F

Max Service Temperature (continuous)

400°C752 °F
350°C662 °F

Same in both: Specific Heat Capacity 750 J/kg·K0.18 BTU/lb·°F · Min Service Temperature -269°C-452 °F · Max Service Temperature (short-term) 500°C932 °F

Electrical

Conductivity and insulation.

Electrical Resistivity

1.5×10⁻⁵ Ω·m591 µΩ·in
1.6×10⁻⁵ Ω·m630 µΩ·in

Volume Resistivity

0 Ω·cm
0 Ω·cm

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

85 / 100
90 / 100

UV / Weathering Resistance

90 / 100
60 / 100

Manufacturability

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

Machinability

15 / 100
25 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

30 kg CO₂/kg
28 kg CO₂/kg

Embodied Water

500 L/kg59.9 gal/lb
—

Same in both: Embodied Energy (primary production) 400 MJ/kg171,969 BTU/lb · Typical Recycled Content 0%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

2,503 kN·m/kg
2,722 kN·m/kg

Specific Stiffness (E / density)

136.9 MN·m/kg
127.8 MN·m/kg

Thermal Diffusivity

5.1 mm²/s
7 mm²/s

Thermal Shock Resistance Index

-207
-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

CapabilityAS4DT700S
Default condition——
Relative cost$$$$ High$$$$ High
Min. machined wall——
Best machined surface——

AS4D vs T700S — frequently asked

Is T700S stronger than AS4D?

Yes. T700S has a typical tensile strength of 4,900 MPa (711 ksi) against 4,480 MPa (650 ksi) for AS4D — about 9% more.

Which is cheaper, AS4D 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, AS4D or T700S?

T700S, by a small margin. Both rate poor for machinability — 25/100 against 15/100 for AS4D.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AS4D 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.