PA-CF vs PAHT-CF vs PPA-CF vs PPS-CF: Which Carbon Fibre?
How the four carbon-fibre filaments we print compare on heat, stiffness, toughness, humidity and chemicals, and how to pick the right one for your part.
Carbon-fibre filaments are what you reach for when PETG, ASA or plain nylon are not stiff enough or not heat resistant enough. We print four of them: PA-CF, PAHT-CF, PPA-CF and PPS-CF. They look the same (matte black, slightly textured) but they behave very differently once a part gets hot, wet or splashed with oil.
This guide explains what each one is, how they compare, and how to choose. The short version: start with PA-CF, and only step up when your part's temperature, humidity or chemical exposure asks for it.
What "Carbon Fibre" Means in a 3D Printing Filament
All four are a base plastic filled with short, chopped carbon fibres. The fibres make the plastic much stiffer, cut warping and shrinkage, and give the matte finish. They are not the long woven sheets used in a bike frame, so a printed part is stiff and light rather than as strong as a composite layup.
The base plastic is what really sets each material apart:
- PA-CF is nylon (polyamide) with carbon fibre. Stiff, tough and the most affordable of the four.
- PAHT-CF is a high-temperature nylon with carbon fibre. It takes more heat and absorbs less moisture than PA-CF.
- PPA-CF is polyphthalamide, a semi-aromatic high-performance nylon, with carbon fibre. It is our stiffest material and resists oils, fuels and coolants.
- PPS-CF is polyphenylene sulfide with carbon fibre. It has the highest heat and chemical resistance we print and is flame retardant by nature, but it is brittle.
Side-by-Side Comparison
Ratings are relative within the carbon-fibre group. Temperatures are the rough working limits we quote on each material page, not a certified rating for your part.
| PA-CF | PAHT-CF | PPA-CF | PPS-CF | |
|---|---|---|---|---|
| Working temperature | ~150 °C | ~180 °C | ~220 °C | ~260 °C |
| Stiffness | High | High | Highest | High |
| Impact toughness | Good | Good | Fair | Low (brittle) |
| Humidity stability | Fair | Good | Good | Excellent |
| Chemical resistance | Good | Good | Excellent | Best |
| Flame retardant | No | No | No | Yes |
| Relative price | $ | $$ | $$$ | $$$$ |
How to Choose, Step by Step
Work down this list and stop at the first material that meets every requirement. Each step up costs more, so there is no point paying for heat or chemical resistance a part will never use.
- Does it need carbon fibre at all? If the part stays below about 80 °C and does not need to be especially stiff, PETG or ASA will be cheaper, faster and available in more colours. If it needs to flex or take impacts, plain nylon or PC is often the better choice.
- Stiff part, normal conditions: PA-CF. Brackets, drone and RC frames, jigs and replacement gears that see up to about 150 °C.
- Runs hot or lives somewhere damp: PAHT-CF. Parts beside a motor, in a parked car or in a humid plant room, up to about 180 °C. Read our PAHT-CF guide.
- Above 200 °C, near oils or fuels, or replacing machined metal: PPA-CF. Read our PPA-CF guide.
- Harsh chemicals, flame sensitivity or extreme heat on a static part: PPS-CF. Read our PPS-CF guide.
Common Mistakes When Picking an Engineering Filament
- Picking the most expensive option "to be safe". PPS-CF has the best heat and chemical numbers, but it is the most brittle of the four. A clip or snap-fit that would be fine in PA-CF can crack in PPS-CF.
- Ignoring humidity. Singapore is humid all year. Standard nylon-based materials take on moisture after printing, which can shift tight fits slightly. If a press-fit or bolt pattern must stay exact, PAHT-CF, PPA-CF or PPS-CF hold their size better.
- Expecting the same strength in every direction. Like every FDM print, a carbon-fibre part is weakest across its layers. Orientation matters as much as material. Our guide on how strong 3D printed parts are covers this.
- Designing thin, sharp details. Fibre-filled plastics are stiffer and less forgiving. Use generous fillets and walls, and avoid very fine features.
What Is the Same Across All Four
- Matte black only. There are no colour options for any of our carbon-fibre materials.
- Dried before every print. We dry each spool before the job because damp filament prints weak and rough. That adds roughly 12–24 hours, and the ready-by date on your quote already includes it.
- Hardened nozzle. Carbon fibre wears out a standard brass nozzle, so we print these on hardened nozzles.
- Bambu Lab printers. We print on Bambu Lab H2-series machines with a heated chamber. Our PAHT-CF, PPA-CF and PPS-CF are Bambu Lab's own filaments.
- A flat handling fee. The drying and nozzle setup are billed as a small flat fee per order, shown as its own line on your quote rather than hidden in the per-gram price.
- Supports are harder to remove. They break off roughly, so design to need as few as you can. Our FDM design reference has the rules.
Not Sure Which One You Need?
Tell us what the part does, how hot it gets and what it touches. We will suggest the cheapest material that does the job, and if a carbon-fibre grade is overkill we will say so. You can also upload your file for an instant quote in any of the four and compare the prices yourself.
