How Strong Is Carbon Fiber Filament for 3D Printing
- Tamara Arkhangelskaya
- Jul 9
- 3 min read
Updated: Jul 22
Carbon fiber 3D printer filament is often marketed as a high-strength material for functional parts. But how strong is it really compared to standard PLA, PETG, or Nylon? And where does it fit into the broader range of engineering materials used in 3D printing?
In this post, we look at real tensile strength data from recent studies and explore where carbon fiber filaments deliver practical value.
What Is Carbon Fiber Filament and How It Works
Carbon fiber filament is a composite material where chopped carbon fibers are added to a base polymer like PLA, PETG, or Nylon. These short fibers reinforce the polymer matrix, improving its stiffness and strength. Because the fibers are not continuous, the improvement depends on how well the material is printed and how the fibers are distributed.
Carbon fiber filaments are known for being more brittle than their base counterparts. They also wear down brass nozzles quickly, which is why a hardened steel or ruby nozzle is strongly recommended. Additionally, carbon fiber makes the filament less flexible and more prone to snapping if coiled tightly. However, when printed correctly, these filaments produce parts with good dimensional stability and a matte, professional-looking surface.
Comparing Carbon Fiber PLA, PETG, and Nylon
Each carbon fiber filament starts with a different base material. PLA-CF is the easiest to print but also the most brittle. PETG-CF offers more flexibility and layer adhesion. Nylon-CF, often branded as NylonX, is more difficult to print but delivers the highest mechanical strength.
Material | Approximate Tensile Strength | Source |
PLA-CF | 38 MPa (XY), 26 MPa (Z) | |
PETG-CF | 35 ± 5 MPa | |
Nylon-CF | 102 ± 7 MPa |
Insights from Recent Research
Two studies explored the tensile strength of PLA and PLA-CF in detail:
A 2022 study published on MDPI tested FDM-printed PLA and PLA-CF samples and reported that PLA-CF had a lower tensile strength (approx. 49.41 MPa) compared to PLA (approx. 54.51 MPa). The authors noted this may be due to weak bonding between the carbon fibers and PLA polymer. However, the same study found that PLA-CF demonstrated a higher Young’s modulus and slightly better elongation at break. (MDPI)
Another study, published in 2021 via the NIH, found an opposite trend under different print conditions. In thin PLA specimens printed in the Y orientation, PLA had a tensile strength of approx. 43.05 MPa, while PLA-CF improved to approx. 56.77 MPa. This indicates the benefits of carbon fiber reinforcement can depend heavily on orientation and geometry. (NIH)
Similarly, a 2024 study presented at the E3S Web of Conferences showed that PETG samples produced by FDM had tensile strength values mostly in the low 30 MPa range. In contrast, carbon fiber PETG samples achieved tensile strengths in the upper 30 MPa range, peaking at over 38 MPa in optimized prints (E3S).
Another 2022 study investigated how carbon fiber reinforcement affects the tensile strength of nylon composites (ResearchGate). Using different carbon fiber percentages and raster angles, the researchers found that nylon with 10 percent carbon fiber content printed at 0 degrees achieved the highest tensile strength of the tested configurations. The orientation of printing and amount of fiber played a key role in mechanical performance.
These findings highlight that the performance of carbon fiber filaments depends on how they are processed, specifically, on their print orientation, wall thickness, and part geometry.
For more details on how to print the base materials, explore our page on FDM 3D printing. You can also find helpful material-specific information on PETG printing or PLA printing depending on your application.
Who Should Consider Carbon Fiber Filament
Carbon fiber filament is most useful for printing stiff functional parts. This includes load-bearing brackets, jigs and fixtures, and durable enclosures where rigidity is more important than flexibility.
However, these filaments require the right setup. You will need a printer with a hardened nozzle, a direct drive extruder (for nylon-based filaments), and active filament drying to avoid moisture-related print issues. While this is not a full technical how-to, it is important to highlight that poor hardware or filament handling can reduce the expected benefits.
Some tips on how to print carbon fiber filament can be found in manufacturer documentation or slicing software profiles specifically tuned for these materials.
If you are deciding between standard resin and tough resin, our post on standard resin vs tough resin for SLA printing explains the differences and when to use each.
Keep in mind that carbon fiber may increase stiffness and strength, but it also reduces flexibility. If you need a balance between toughness and printability, PETG-CF may be your best option. For maximum strength and heat resistance, NylonX is the better choice. If you require professional 3D printing services in Boston and across the US using CF-based materials, we will be very happy to help.
