T300 vs T700 Carbon Fiber for FPV Drone Frames
The short version: T300 and T700S are both standard-modulus carbon fibers. Toray lists both at a nominal tensile modulus of 230 GPa, but T700S is rated at 4,900 MPa tensile strength versus 3,530 MPa for T300, with higher strain at failure as well. That makes T700S the higher-strength fiber on paper. It does not mean every plate labeled T700 will automatically outperform every T300 plate.
T300 vs T700S fiber data
| Fiber | Tensile strength | Tensile modulus | Strain at failure |
|---|---|---|---|
| T300 | 3,530 MPa | 230 GPa | 1.5% |
| T700S | 4,900 MPa | 230 GPa | 2.1% |
Sources: Toray T300 data sheet and Toray T700S data sheet.
Strength and stiffness are not the same thing
The matching 230 GPa modulus number is important. Modulus is a measure related to elastic stiffness; tensile strength is the stress the fiber can withstand before failure in the specified test. T700S gains substantially in strength and strain capability without moving into a higher-modulus fiber class. For an FPV frame, that distinction matters because a plate needs stiffness for flight behavior and enough damage tolerance for crashes.
The fiber name does not describe the whole carbon plate
An FPV plate is a laminate, not a bundle of bare fibers. Resin system, fiber volume, fabric architecture, ply orientation, cure quality, void content, machining quality, plate thickness, arm geometry, cutouts and edge finish all affect the finished part. A badly made “T700” laminate can be a worse frame plate than a well-made T300 laminate.
That is why comparing FPV carbon only by the fiber label is incomplete. The useful question is: what fiber is used, how is the laminate made, and how is the frame geometry using that material?
Why Funkolius uses T700 on performance frames
Funkolius uses T700 carbon on platforms where higher fiber strength is useful without chasing a higher-modulus, more specialized material. The Impetus 2 and MOTUS 4SX are examples. Plate thickness and geometry are still chosen separately for the job; material grade is only one part of the design.
Bottom line
T300: established standard-modulus fiber with balanced properties and a long production history. T700S: also standard modulus, but with higher rated tensile strength and strain at failure. For FPV frames, T700S gives a stronger fiber starting point, while the finished plate and frame design determine whether that advantage is actually realized.
