T800S against T700S (Toray data sheets)
Where to buy| Property | T700S standard modulus | T800S intermediate modulus |
|---|---|---|
| Tensile strength | 711 ksi (4,900 MPa) | 853 ksi (5,880 MPa) |
| Tensile modulus | 33.4 Msi (230 GPa) | 42.7 Msi (294 GPa) |
| Strain at failure | 2.1% | 2.0% |
| Density | 1.80 g/cm³ | 1.80 g/cm³ |
| Filament diameter | 7 µm | 5 µm |
| Yield, 12K tow | 800 g/1000 m | 515 g/1000 m |
| Laminate tensile strength (60% Vf) | 415 ksi (2,860 MPa) | 477 ksi (3,290 MPa) |
| Laminate tensile modulus (60% Vf) | 19 Msi (134 GPa) | 24 Msi (163 GPa) |
| Laminate compressive strength | 210 ksi (1,450 MPa) | 216 ksi (1,490 MPa) |
| ILSS | 13 ksi (86.9 MPa) | 13 ksi (87.9 MPa) |
Toray sheets: T700S Rev. 11/24/2025, T800S Rev. 04/13/2018. Laminates normalised to 60% fiber volume, epoxy cured at 130 °C (the T800S sheet names #2592 epoxy). The strength gain in the fiber shows up as 15% in tensile but only 3% in compression of the laminate.
What the gain buys, and what it does not
Toray describes T800S as an intermediate modulus, high tensile strength fiber designed to meet the weight-saving demand of aircraft and high-performance products; it comes in 12K and 24K tows. Because the laminate compressive strength rises only from 210 to 216 ksi, buckling or compression-governed parts do not gain what a tension-governed part does.
In a repair, the fiber grade is a design choice already made. A patch cannot be switched from one fiber grade to another without approved data.
Standard or intermediate
T700S
- Fiber strength
- 4,900 MPa (711 ksi)
- Fiber modulus
- 230 GPa (33.4 Msi)
- Laminate compression
- 1,450 MPa (210 ksi)
T800S
- Fiber strength
- 5,880 MPa (853 ksi)
- Fiber modulus
- 294 GPa (42.7 Msi)
- Laminate compression
- 1,490 MPa (216 ksi)
Limits — when NOT to use this
- Lot averages, not allowables.
- Not interchangeable with standard modulus in a repair without approved data.
Where to buy
Distributors coming soon.
Sources
- Toray Composite Materials America, TORAYCA T800S Intermediate Modulus Carbon Fiber Data Sheet (Rev. 04/13/2018) — fiber and composite properties, tow sizes, resin compatibility.
- Toray Composite Materials America, TORAYCA T700S Standard Modulus Carbon Fiber Data Sheet (Rev. 11/24/2025) — fiber and composite properties, tow sizes, resin compatibility.
- FAA-H-8083-31B, AMT Handbook — Airframe, Volume 1 (2023), Chapter 7 — carbon fiber (p. 7-5).