CF
HexTow® AS4 3K
Hexcel ? Aerospace Standard
Manufacturer page / TDSDescription
HexTow® AS4 carbon fiber is a continuous, high strength, high strain, PAN based fiber. Suggested for use in weaving, prepregging, filament winding, braiding, and pultrusion.
Comparative overview
Carbon fiber — High-strength standard-modulus carbon
Strengths: Higher tensile strength and strain than baseline carbon while retaining mature standard-modulus processing.
When to use: Select for pressure vessels, pultrusion, industrial structures and sporting goods requiring strength with controlled cost.
Key tradeoffs: Less stiff than IM/HM grades; conductive and more expensive than baseline large-tow carbon.
Qualitative ratings (1–10 scale)
| Relative cost | 8/10 — High — aerospace/high-performance PAN carbon with controlled precursor, surface treatment and sizing. |
|---|---|
| EM transparency | 1/10 — Very poor — electrically conductive; causes reflection/attenuation rather than RF transparency. |
| Temperature / fire resistance | 6/10 — Good — non-melting but oxidation in air and the matrix system cap fire/hot-service performance. |
| Impact / penetration resistance | 7/10 — High — higher strain and tensile strength than HM/UHM carbon improve impact response, but delamination and brittle fiber fracture remain. Stored TDS elongation: 1.8%. |
| Electrical / thermal conductivity | 7/10 — High — electrically conductive with moderate axial thermal conductivity typical of PAN carbon. Stored axial thermal conductivity: 6.83 W/m·K. |
| Specific tensile strength | 8/10 — 8/10 | 2514.5 kN·m/kg | Product TDS |
| Atmospheric durability | 9/10 — Excellent — carbon fiber is intrinsically resistant to UV, moisture and salt exposure; long-term laminate durability is usually governed by sizing, matrix, galvanic coupling and interfaces rather than the fiber. |
| Sustainability (CO₂e) | 5/10 — 19.85 kg CO₂e/kg fiber — High emissions — data quality: High |
Technical properties
| Tensile strength | 4501.0 MPa |
|---|---|
| Tensile modulus | 231.0 GPa |
| Density | 1.79 g/cm³ |
| Filament diameter | 7.1 µm |
Applications and processing
AerospaceBraidingFilament WindingPrepreg TapePultrusionWeaving