Carbon fiber (IM7)
Intermediate-modulus PAN carbon fiber; higher stiffness and strength than AS4 — primary aircraft structure.
Also called: Hexcel IM7, intermediate modulus carbon fibre, IM7 12k, IM7 composite
| Property | Value | Source | Method | Conditions | Note |
|---|---|---|---|---|---|
| Density | 1.78 g/cm³ | Hexcel HexTow carbon fiber product datasheet | — | 23 °C, dry | — |
| Young's modulus E | 276 GPa | Hexcel HexTow carbon fiber product datasheet | — | 23 °C, dry | axial |
| Tensile strength | 5516 MPa | Hexcel HexTow carbon fiber product datasheet | — | 23 °C, dry | — |
IM7 is an intermediate-modulus, high-strength PAN-based carbon fibre made by Hexcel. It sits between standard-modulus fibres like T300 and AS4 (around 230 GPa) and the stiffer high-modulus grades — trading a little stiffness for high strength and a useful strain-to-failure.
That balance is why IM7 is a workhorse in aerospace primary structure, launch vehicles, pressure vessels and top-tier sporting goods: it gives near-high-modulus stiffness without the brittleness. It is most often used in an epoxy prepreg (for example IM7/8552).
The values here are for the dry fibre along its axis. In a real laminate the effective properties depend on the fibre volume fraction and the layup — run the numbers in the laminate and micromechanics calculators.
See where Carbon fiber fits in a real product, and what it competes with:
- Hexcel HexTow carbon fiber product datasheet
Typical room-temperature values for learning and preliminary design; grades vary. Always confirm against the supplier datasheet before design work. Data policy: docs/DATA-SOURCES.md in the repository.