Fiber comparison
Carbon fiber (AS4) vs Aramid fiber (Kevlar 49)
Every value below is a typical room-temperature figure with its source, test method and conditions — the same dataset that drives the calculators.
| Property | Carbon fiber (AS4) | Aramid fiber (Kevlar 49) | Difference |
|---|---|---|---|
| Density | 1.79 g/cm³ | 1.44 g/cm³ | Carbon fiber (AS4) — 24% higher |
| Young's modulus E | 231 GPa | 131 GPa | Carbon fiber (AS4) — 76% higher |
| Tensile strength | 4447 MPa | 3620 MPa | Carbon fiber (AS4) — 23% higher |
Where these numbers come from
- Hexcel HexTow carbon fiber product datasheet
- Daniel & Ishai, Engineering Mechanics of Composite Materials, 2nd ed.
Typical room-temperature values for learning and preliminary design; grades vary widely and a supplier datasheet always overrides a textbook figure. Confirm against the datasheet before design work.